Download - Groundwater Sept2011
832019 Groundwater Sept2011
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DNJ
Groundwater
Geology 11 ndash Principles of Geology
A M P Tengonciangamp D D N Javier
Department of Physical Sciences
University of the Philippines Baguio
The Hydrologic Cycle
Precipitation =Runoff + Infiltration + Transpiration + Evaporation
httpgawaterusgsgovedugraphicsearthwheredistributiongifTarbuckamp Lutgens 20xx Earth Science
Earthrsquos Inventory
of WaterSaline
Fresh25 of all the fresh
water on Earth
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- all water in the ground occupying the pore spaces within rock
and regolith
- that portion of precipitation (rainfall snow etc) which seeps
through the ground and is stored below the surface
Geologic importance erosional agent equalizes streamflow
(reservoir for rivers during periods of no rain)
Economic importance drinking water irrigation livestock power
generation industrial cooling
Groundwater Sources of groundwater
bull Connate water ndash water that has remainedtrapped in a sedimentary rock since the original
sediments were deposited in the water prior tolithification may be very old and saline
bull Meteoric water ndash water of atmospheric originwhich reaches the Earthrsquos surface as rainfall orseepage from surface water bodies
bull Juvenile water ndash original water formed frommagmatic processes has never been in theatmosphere
bull Zone of aeration ndash
unsaturated zone vadose
zone (Lat shallow)
ndash water is able to pass
through to reach the
water-table (vadose
water)
ndash pore spaces are not
completely filled with
water
bull Zone of saturation ndash
phreatic zone (Gr
wellspring)
ndash pore spaces are
saturated with water
bull Water table ndash upper surface
of zone of saturation
The Water Table
-boundary between the
unsaturated (vadose)
zone and saturated zone
of an aquifer
Note
The vadose zone has an
important
environmental role in
groundwater systems
Surface pollutants must
filter through the vadose
zone before entering the
zone of saturation
bull Capillary fringe ndash zone
where water is drawnupward by capillary
action immediately
above the water table
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Water Table
bull Important in predicting
the productivity of wells
bullExplains the changes inflows of springs and
streams
bull Accounts for fluctuation
in levels of lakes
bull Unobservable directly
but can be mapped and
studied in detail in areas
where wells are
numerous
bull The shape of the water
table is usually a subdued
replica of the surfacetopography
bull Irregularities are due to
ndash variations in rainfall
ndash nature of carrying
material
ndash slow and varied
groundwater
movement under
different conditions
downward
movement of
water from the
soil to the water
table
Porosity
bull Measure of how much of a rock is open space
bull Percentage of total volume of rock or sediment thatconsists of pore spaces (absolute porosity)
bull Effective porosity ndash the proportion of the rock or
sediment consisting of interconnected pores
bull Dictates the amount of water stored by material
Porosity in Sediments
Porosity in differentsedimentsA) A porosity of 30 percent
in a reasonably well-sortedsedimentB) A porosity of 15 percentin a poorly sorted sedimentin which fine particles fill
spaces between largergrainsC) Reduction in porosity inan otherwise very poroussediment due to cementthat binds particles together
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Porosity
bull Primary ndash created by the same
processes that formed the
material
ndash sediments amp sedimentary
rocks
ndash vesicular lava deposits
bull Secondary ndash develops after the
material was formed
ndash rock fractures (joints and
faults)
ndash cavities formed by
dissolution of soluble rocks22
Bedient et al 1999
Typical Values of Porosity
Permeability
bull Measure of the ease with which water can move
through a porous rock
bull The ability of a material to transmit fluid
bull Related to the effective porosity of a material
ndash the smaller the pore spaces the slower the
movement of water
ndash sandstone ndash good permeability
ndash shale ndash poor permeability
Porosity and Permeability
Porous
and
Permeable
Porous but
not
Permeable
Reduced
Porosity and
Permeability
Porosity and Permeability
shale sandstone limestone
Porous and PermeablePorous but not Permeable
Porosity and permeability
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HYDRAULIC HEAD FLUID POTENTIAL = h (length units)bull Measure of energy potential (essentially is a measure ofelevationalgravitational potential energy)
bull The driving force for groundwater flow
bull
Water flows from high to low fluid potential or hydraulic (even if thismeans it may go uphill)
bull Hydraulic head is used to determine the hydraulic gradient
Hydraulic head = the driving force that moves groundwater Thehydraulic head combines fluid pressure and gradient and can bethought of as the standing elevation that water will rise to in a wellallowed to come to equilibrium with the subsurface Groundwateralways moves from an area of higher hydraulic head to an area of lowerhydraulic head Therefore groundwater not only flows downward it canalso flow laterally or upward
Groundwater Movement
S Hughes 2003
Groundwater Flow Velocity - Darcyrsquos Law
v = K (h1-h2)lv velocity
K hydraulic conductivity
The velocity of groundwater is based on hydraulic conductivity (K)as well as the hydraulic head (I)
The equation to describe the relations between subsurface materialsand the movement of water through them is
Q = KIAQ = Discharge = volumetric flow rate volume of water flowingthrough an aquifer per unit time (m3 day)
A = Area through which the groundwater is flowing cross-sectionalarea of flow (aquifer width x thickness in m 2)
Rearrange the equation to QA = KI known as the flux (v) which isan apparent velocity
Groundwater Movement -- Darcyrsquos Law
S Hughes 2003
Groundwater Movement -- Darcyrsquos Law
Q = KIA -- Henry Darcy 1856 studied water flowing through porous
material His equation describes groundwater flow
Darcyrsquos experiment
bull Water is applied underpressure through end Aflows through the pipe anddischarges at end B
bull Water pressure ismeasured using piezometertubes
Hydraulic head = dh (change in height between A and B)Flow length = dL (distance between the two tubes)Hydraulic gradient (I) = dh dL
S Hughes 2003
High K materials
Groundwater MovementTable 106 in textbook (Keller 2000)
Porosity and hydraulic conductivity (rate at which water moves througha material) of selected earth materials
Hydraulic
Porosity ConductivityMaterial () (mday)
UnconsolidatedClay 45 0041Sand 35 328Gravel 25 2050Gravel and sand 20 820
RockSandstone 15 287Dense limestone or shale 5 0041Granite 1 00041
S Hughes 2003
Hydraulic conductivity = ability of material to allow water to move through itexpressed in terms of mday (distancetime) It is a function of the size andshape of particles and the size shape and connectivity of pore spaces
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Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining bedsDecades
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
WellsWater table
Flow lines
Confining beds
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Millennia
Centuries
Decades
Years
Days
Dischargearea
WellsWater table
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Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
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Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
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Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
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Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
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Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
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Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
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Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
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bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
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Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
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At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
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Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
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Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
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Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
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Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
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Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
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Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
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The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
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Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
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DNJ
- all water in the ground occupying the pore spaces within rock
and regolith
- that portion of precipitation (rainfall snow etc) which seeps
through the ground and is stored below the surface
Geologic importance erosional agent equalizes streamflow
(reservoir for rivers during periods of no rain)
Economic importance drinking water irrigation livestock power
generation industrial cooling
Groundwater Sources of groundwater
bull Connate water ndash water that has remainedtrapped in a sedimentary rock since the original
sediments were deposited in the water prior tolithification may be very old and saline
bull Meteoric water ndash water of atmospheric originwhich reaches the Earthrsquos surface as rainfall orseepage from surface water bodies
bull Juvenile water ndash original water formed frommagmatic processes has never been in theatmosphere
bull Zone of aeration ndash
unsaturated zone vadose
zone (Lat shallow)
ndash water is able to pass
through to reach the
water-table (vadose
water)
ndash pore spaces are not
completely filled with
water
bull Zone of saturation ndash
phreatic zone (Gr
wellspring)
ndash pore spaces are
saturated with water
bull Water table ndash upper surface
of zone of saturation
The Water Table
-boundary between the
unsaturated (vadose)
zone and saturated zone
of an aquifer
Note
The vadose zone has an
important
environmental role in
groundwater systems
Surface pollutants must
filter through the vadose
zone before entering the
zone of saturation
bull Capillary fringe ndash zone
where water is drawnupward by capillary
action immediately
above the water table
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Water Table
bull Important in predicting
the productivity of wells
bullExplains the changes inflows of springs and
streams
bull Accounts for fluctuation
in levels of lakes
bull Unobservable directly
but can be mapped and
studied in detail in areas
where wells are
numerous
bull The shape of the water
table is usually a subdued
replica of the surfacetopography
bull Irregularities are due to
ndash variations in rainfall
ndash nature of carrying
material
ndash slow and varied
groundwater
movement under
different conditions
downward
movement of
water from the
soil to the water
table
Porosity
bull Measure of how much of a rock is open space
bull Percentage of total volume of rock or sediment thatconsists of pore spaces (absolute porosity)
bull Effective porosity ndash the proportion of the rock or
sediment consisting of interconnected pores
bull Dictates the amount of water stored by material
Porosity in Sediments
Porosity in differentsedimentsA) A porosity of 30 percent
in a reasonably well-sortedsedimentB) A porosity of 15 percentin a poorly sorted sedimentin which fine particles fill
spaces between largergrainsC) Reduction in porosity inan otherwise very poroussediment due to cementthat binds particles together
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Porosity
bull Primary ndash created by the same
processes that formed the
material
ndash sediments amp sedimentary
rocks
ndash vesicular lava deposits
bull Secondary ndash develops after the
material was formed
ndash rock fractures (joints and
faults)
ndash cavities formed by
dissolution of soluble rocks22
Bedient et al 1999
Typical Values of Porosity
Permeability
bull Measure of the ease with which water can move
through a porous rock
bull The ability of a material to transmit fluid
bull Related to the effective porosity of a material
ndash the smaller the pore spaces the slower the
movement of water
ndash sandstone ndash good permeability
ndash shale ndash poor permeability
Porosity and Permeability
Porous
and
Permeable
Porous but
not
Permeable
Reduced
Porosity and
Permeability
Porosity and Permeability
shale sandstone limestone
Porous and PermeablePorous but not Permeable
Porosity and permeability
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HYDRAULIC HEAD FLUID POTENTIAL = h (length units)bull Measure of energy potential (essentially is a measure ofelevationalgravitational potential energy)
bull The driving force for groundwater flow
bull
Water flows from high to low fluid potential or hydraulic (even if thismeans it may go uphill)
bull Hydraulic head is used to determine the hydraulic gradient
Hydraulic head = the driving force that moves groundwater Thehydraulic head combines fluid pressure and gradient and can bethought of as the standing elevation that water will rise to in a wellallowed to come to equilibrium with the subsurface Groundwateralways moves from an area of higher hydraulic head to an area of lowerhydraulic head Therefore groundwater not only flows downward it canalso flow laterally or upward
Groundwater Movement
S Hughes 2003
Groundwater Flow Velocity - Darcyrsquos Law
v = K (h1-h2)lv velocity
K hydraulic conductivity
The velocity of groundwater is based on hydraulic conductivity (K)as well as the hydraulic head (I)
The equation to describe the relations between subsurface materialsand the movement of water through them is
Q = KIAQ = Discharge = volumetric flow rate volume of water flowingthrough an aquifer per unit time (m3 day)
A = Area through which the groundwater is flowing cross-sectionalarea of flow (aquifer width x thickness in m 2)
Rearrange the equation to QA = KI known as the flux (v) which isan apparent velocity
Groundwater Movement -- Darcyrsquos Law
S Hughes 2003
Groundwater Movement -- Darcyrsquos Law
Q = KIA -- Henry Darcy 1856 studied water flowing through porous
material His equation describes groundwater flow
Darcyrsquos experiment
bull Water is applied underpressure through end Aflows through the pipe anddischarges at end B
bull Water pressure ismeasured using piezometertubes
Hydraulic head = dh (change in height between A and B)Flow length = dL (distance between the two tubes)Hydraulic gradient (I) = dh dL
S Hughes 2003
High K materials
Groundwater MovementTable 106 in textbook (Keller 2000)
Porosity and hydraulic conductivity (rate at which water moves througha material) of selected earth materials
Hydraulic
Porosity ConductivityMaterial () (mday)
UnconsolidatedClay 45 0041Sand 35 328Gravel 25 2050Gravel and sand 20 820
RockSandstone 15 287Dense limestone or shale 5 0041Granite 1 00041
S Hughes 2003
Hydraulic conductivity = ability of material to allow water to move through itexpressed in terms of mday (distancetime) It is a function of the size andshape of particles and the size shape and connectivity of pore spaces
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Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining bedsDecades
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
WellsWater table
Flow lines
Confining beds
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Millennia
Centuries
Decades
Years
Days
Dischargearea
WellsWater table
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Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
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Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
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Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
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Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
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Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
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DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
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Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
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bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
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Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
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At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
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Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
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DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
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Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
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Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
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Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
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Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
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The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
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Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
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Water Table
bull Important in predicting
the productivity of wells
bullExplains the changes inflows of springs and
streams
bull Accounts for fluctuation
in levels of lakes
bull Unobservable directly
but can be mapped and
studied in detail in areas
where wells are
numerous
bull The shape of the water
table is usually a subdued
replica of the surfacetopography
bull Irregularities are due to
ndash variations in rainfall
ndash nature of carrying
material
ndash slow and varied
groundwater
movement under
different conditions
downward
movement of
water from the
soil to the water
table
Porosity
bull Measure of how much of a rock is open space
bull Percentage of total volume of rock or sediment thatconsists of pore spaces (absolute porosity)
bull Effective porosity ndash the proportion of the rock or
sediment consisting of interconnected pores
bull Dictates the amount of water stored by material
Porosity in Sediments
Porosity in differentsedimentsA) A porosity of 30 percent
in a reasonably well-sortedsedimentB) A porosity of 15 percentin a poorly sorted sedimentin which fine particles fill
spaces between largergrainsC) Reduction in porosity inan otherwise very poroussediment due to cementthat binds particles together
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DNJ
Porosity
bull Primary ndash created by the same
processes that formed the
material
ndash sediments amp sedimentary
rocks
ndash vesicular lava deposits
bull Secondary ndash develops after the
material was formed
ndash rock fractures (joints and
faults)
ndash cavities formed by
dissolution of soluble rocks22
Bedient et al 1999
Typical Values of Porosity
Permeability
bull Measure of the ease with which water can move
through a porous rock
bull The ability of a material to transmit fluid
bull Related to the effective porosity of a material
ndash the smaller the pore spaces the slower the
movement of water
ndash sandstone ndash good permeability
ndash shale ndash poor permeability
Porosity and Permeability
Porous
and
Permeable
Porous but
not
Permeable
Reduced
Porosity and
Permeability
Porosity and Permeability
shale sandstone limestone
Porous and PermeablePorous but not Permeable
Porosity and permeability
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HYDRAULIC HEAD FLUID POTENTIAL = h (length units)bull Measure of energy potential (essentially is a measure ofelevationalgravitational potential energy)
bull The driving force for groundwater flow
bull
Water flows from high to low fluid potential or hydraulic (even if thismeans it may go uphill)
bull Hydraulic head is used to determine the hydraulic gradient
Hydraulic head = the driving force that moves groundwater Thehydraulic head combines fluid pressure and gradient and can bethought of as the standing elevation that water will rise to in a wellallowed to come to equilibrium with the subsurface Groundwateralways moves from an area of higher hydraulic head to an area of lowerhydraulic head Therefore groundwater not only flows downward it canalso flow laterally or upward
Groundwater Movement
S Hughes 2003
Groundwater Flow Velocity - Darcyrsquos Law
v = K (h1-h2)lv velocity
K hydraulic conductivity
The velocity of groundwater is based on hydraulic conductivity (K)as well as the hydraulic head (I)
The equation to describe the relations between subsurface materialsand the movement of water through them is
Q = KIAQ = Discharge = volumetric flow rate volume of water flowingthrough an aquifer per unit time (m3 day)
A = Area through which the groundwater is flowing cross-sectionalarea of flow (aquifer width x thickness in m 2)
Rearrange the equation to QA = KI known as the flux (v) which isan apparent velocity
Groundwater Movement -- Darcyrsquos Law
S Hughes 2003
Groundwater Movement -- Darcyrsquos Law
Q = KIA -- Henry Darcy 1856 studied water flowing through porous
material His equation describes groundwater flow
Darcyrsquos experiment
bull Water is applied underpressure through end Aflows through the pipe anddischarges at end B
bull Water pressure ismeasured using piezometertubes
Hydraulic head = dh (change in height between A and B)Flow length = dL (distance between the two tubes)Hydraulic gradient (I) = dh dL
S Hughes 2003
High K materials
Groundwater MovementTable 106 in textbook (Keller 2000)
Porosity and hydraulic conductivity (rate at which water moves througha material) of selected earth materials
Hydraulic
Porosity ConductivityMaterial () (mday)
UnconsolidatedClay 45 0041Sand 35 328Gravel 25 2050Gravel and sand 20 820
RockSandstone 15 287Dense limestone or shale 5 0041Granite 1 00041
S Hughes 2003
Hydraulic conductivity = ability of material to allow water to move through itexpressed in terms of mday (distancetime) It is a function of the size andshape of particles and the size shape and connectivity of pore spaces
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DNJ
Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining bedsDecades
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
WellsWater table
Flow lines
Confining beds
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Millennia
Centuries
Decades
Years
Days
Dischargearea
WellsWater table
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DNJ
Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
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Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
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Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
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Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
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Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
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Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
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Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
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bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
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Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
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At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
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Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
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Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
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Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
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Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
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Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
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Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
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The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
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Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
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Porosity
bull Primary ndash created by the same
processes that formed the
material
ndash sediments amp sedimentary
rocks
ndash vesicular lava deposits
bull Secondary ndash develops after the
material was formed
ndash rock fractures (joints and
faults)
ndash cavities formed by
dissolution of soluble rocks22
Bedient et al 1999
Typical Values of Porosity
Permeability
bull Measure of the ease with which water can move
through a porous rock
bull The ability of a material to transmit fluid
bull Related to the effective porosity of a material
ndash the smaller the pore spaces the slower the
movement of water
ndash sandstone ndash good permeability
ndash shale ndash poor permeability
Porosity and Permeability
Porous
and
Permeable
Porous but
not
Permeable
Reduced
Porosity and
Permeability
Porosity and Permeability
shale sandstone limestone
Porous and PermeablePorous but not Permeable
Porosity and permeability
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HYDRAULIC HEAD FLUID POTENTIAL = h (length units)bull Measure of energy potential (essentially is a measure ofelevationalgravitational potential energy)
bull The driving force for groundwater flow
bull
Water flows from high to low fluid potential or hydraulic (even if thismeans it may go uphill)
bull Hydraulic head is used to determine the hydraulic gradient
Hydraulic head = the driving force that moves groundwater Thehydraulic head combines fluid pressure and gradient and can bethought of as the standing elevation that water will rise to in a wellallowed to come to equilibrium with the subsurface Groundwateralways moves from an area of higher hydraulic head to an area of lowerhydraulic head Therefore groundwater not only flows downward it canalso flow laterally or upward
Groundwater Movement
S Hughes 2003
Groundwater Flow Velocity - Darcyrsquos Law
v = K (h1-h2)lv velocity
K hydraulic conductivity
The velocity of groundwater is based on hydraulic conductivity (K)as well as the hydraulic head (I)
The equation to describe the relations between subsurface materialsand the movement of water through them is
Q = KIAQ = Discharge = volumetric flow rate volume of water flowingthrough an aquifer per unit time (m3 day)
A = Area through which the groundwater is flowing cross-sectionalarea of flow (aquifer width x thickness in m 2)
Rearrange the equation to QA = KI known as the flux (v) which isan apparent velocity
Groundwater Movement -- Darcyrsquos Law
S Hughes 2003
Groundwater Movement -- Darcyrsquos Law
Q = KIA -- Henry Darcy 1856 studied water flowing through porous
material His equation describes groundwater flow
Darcyrsquos experiment
bull Water is applied underpressure through end Aflows through the pipe anddischarges at end B
bull Water pressure ismeasured using piezometertubes
Hydraulic head = dh (change in height between A and B)Flow length = dL (distance between the two tubes)Hydraulic gradient (I) = dh dL
S Hughes 2003
High K materials
Groundwater MovementTable 106 in textbook (Keller 2000)
Porosity and hydraulic conductivity (rate at which water moves througha material) of selected earth materials
Hydraulic
Porosity ConductivityMaterial () (mday)
UnconsolidatedClay 45 0041Sand 35 328Gravel 25 2050Gravel and sand 20 820
RockSandstone 15 287Dense limestone or shale 5 0041Granite 1 00041
S Hughes 2003
Hydraulic conductivity = ability of material to allow water to move through itexpressed in terms of mday (distancetime) It is a function of the size andshape of particles and the size shape and connectivity of pore spaces
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Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining bedsDecades
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
WellsWater table
Flow lines
Confining beds
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Millennia
Centuries
Decades
Years
Days
Dischargearea
WellsWater table
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Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
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Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
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Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
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Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
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Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
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Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
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Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
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DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 524
eol 11 1st Sem AY2011-12 91920
DNJ
HYDRAULIC HEAD FLUID POTENTIAL = h (length units)bull Measure of energy potential (essentially is a measure ofelevationalgravitational potential energy)
bull The driving force for groundwater flow
bull
Water flows from high to low fluid potential or hydraulic (even if thismeans it may go uphill)
bull Hydraulic head is used to determine the hydraulic gradient
Hydraulic head = the driving force that moves groundwater Thehydraulic head combines fluid pressure and gradient and can bethought of as the standing elevation that water will rise to in a wellallowed to come to equilibrium with the subsurface Groundwateralways moves from an area of higher hydraulic head to an area of lowerhydraulic head Therefore groundwater not only flows downward it canalso flow laterally or upward
Groundwater Movement
S Hughes 2003
Groundwater Flow Velocity - Darcyrsquos Law
v = K (h1-h2)lv velocity
K hydraulic conductivity
The velocity of groundwater is based on hydraulic conductivity (K)as well as the hydraulic head (I)
The equation to describe the relations between subsurface materialsand the movement of water through them is
Q = KIAQ = Discharge = volumetric flow rate volume of water flowingthrough an aquifer per unit time (m3 day)
A = Area through which the groundwater is flowing cross-sectionalarea of flow (aquifer width x thickness in m 2)
Rearrange the equation to QA = KI known as the flux (v) which isan apparent velocity
Groundwater Movement -- Darcyrsquos Law
S Hughes 2003
Groundwater Movement -- Darcyrsquos Law
Q = KIA -- Henry Darcy 1856 studied water flowing through porous
material His equation describes groundwater flow
Darcyrsquos experiment
bull Water is applied underpressure through end Aflows through the pipe anddischarges at end B
bull Water pressure ismeasured using piezometertubes
Hydraulic head = dh (change in height between A and B)Flow length = dL (distance between the two tubes)Hydraulic gradient (I) = dh dL
S Hughes 2003
High K materials
Groundwater MovementTable 106 in textbook (Keller 2000)
Porosity and hydraulic conductivity (rate at which water moves througha material) of selected earth materials
Hydraulic
Porosity ConductivityMaterial () (mday)
UnconsolidatedClay 45 0041Sand 35 328Gravel 25 2050Gravel and sand 20 820
RockSandstone 15 287Dense limestone or shale 5 0041Granite 1 00041
S Hughes 2003
Hydraulic conductivity = ability of material to allow water to move through itexpressed in terms of mday (distancetime) It is a function of the size andshape of particles and the size shape and connectivity of pore spaces
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 624
eol 11 1st Sem AY2011-12 91920
DNJ
Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining bedsDecades
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
WellsWater table
Flow lines
Confining beds
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Millennia
Centuries
Decades
Years
Days
Dischargearea
WellsWater table
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 724
eol 11 1st Sem AY2011-12 91920
DNJ
Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 824
eol 11 1st Sem AY2011-12 91920
DNJ
Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 924
eol 11 1st Sem AY2011-12 91920
DNJ
Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1024
eol 11 1st Sem AY2011-12 91920
DNJ
Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1124
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1224
eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Flow lines
Confining beds
WellsWater table
Millennia
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining bedsDecades
Years
Days
Dischargearea
WellsWater table
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Centuries
Decades
Years
Days
Dischargearea
Unconfinedaquifer
Confinedaquifers
WellsWater table
Flow lines
Confining beds
Unconfinedaquifer
Confinedaquifers
Flow lines
Confining beds
Millennia
Centuries
Decades
Years
Days
Dischargearea
WellsWater table
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
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DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
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DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
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DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
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DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
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DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
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DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
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DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
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DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
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DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 724
eol 11 1st Sem AY2011-12 91920
DNJ
Effluent streams
bull Receive water emergingfrom a submerged spring or
other groundwater seepage
bull The surface of the streamdirectly relates to the watertable thus will rise and fallas the water table rises andfalls
bull Common in temperate totropical climates run yearround
Influent streams
bull May or may not be directly
connected to the water table
bull Supplement the water in the
zone of saturation producing
an upward bulge in the water
table directly underneath
bull Common in arid climates may
be temporary only present
when rainfall or flash flooding
occurs
Groundwater storage amp movement
bull Aquifer ndash permeable rock strata or sediment thattransmits groundwater freely (eg sands gravelsfractured rock)
An aquifer is a formation that allows water to be accessibleat a usable rate
bull Aquitard ndash impermeable rock strata or sedimentthat slows down or retards water movement (egclay non-fractured rock)
bull Aquiclude (aquifuge) ndash porous rock stata or
sediment with poor permeability such that itblocks groundwater movement
Unconfined
Aquifer
They are notsealed off at anypoint
Recharge canoccur anywhere
Water at wtableunder atmpressure
Must lower bucketor pump to accesswater
Unconfined aquifer ndash an aquifer whose upper limit is the water table has no confining
layers that retard vertical water movement
Confined aquifer ndash an aquifer sandwiched between two impermeable strata Confined
aquifers have non-permeable layers above and below the aquifer zone referred
to as aquitards or aquicludes
Unconfined aquifer
-Sealed off
-Transmits waterdown from RA
-Water confined inaquifer unlessdrilled
-Water underhydrostaticpressure
- Water rises wellmay flow
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1024
eol 11 1st Sem AY2011-12 91920
DNJ
Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1124
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
832019 Groundwater Sept2011
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eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 824
eol 11 1st Sem AY2011-12 91920
DNJ
Perched aquifer ndash an unconfined groundwater body supported by a
small impermeable or slowly permeable layer
Spring ndash natural flow of groundwater resulting from the intersection
of the water table with the land surface
Springs
bull Form when an aquicludeblocks the downwardmovement of
groundwater and forces itto move laterally towardsa more permeable bed orarea of less confinement
bull Dependent on rock typesand relationshipsprimary amp secondaryporosity and permeability
Porous limestone overlies an impermeable shale unit and a line
of springs occurs along the hillside where the two rock unitsmeet
Springs issue from the contact between a highly jointed lava flow
and the underlying impermeable mudstone
Springs flow from the place where a fault intersects the ground
surface
Springs
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 924
eol 11 1st Sem AY2011-12 91920
DNJ
Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1024
eol 11 1st Sem AY2011-12 91920
DNJ
Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1124
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1224
eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 924
eol 11 1st Sem AY2011-12 91920
DNJ
Springs Desert Oases
Wells
bull Openings bored into the zone of saturationSuccessful andUnsuccessful Wells
Yields to wells from nonhomogeneous rock can bevariableA) wells that penetratefractures in metamorphicand igneous rocks producewater Dry wells result if nowater-bearing fractures areencounteredB) Perched water bodiesabove the main water tableare held up by aquicludes
and provide shallow sourcesof groundwater Wells thatmiss the perched water bodyand do not reach the deeperwater table are dry
Wellsbull Drawdown ndash lowering of water
table resulting from the
removal of water from a well
cone of depression
bull Hydraulic gradient ndash slope of
the water table increases with
more groundwater extraction
thereby increasing the rate of
groundwater flow into the well
Artesian wells
bull Groundwater under pressure rises above the level of the
aquiferbull Conditions for an artesian system
ndash Water must be confined to an aquifer that is inclined so that
one end can receive water
ndash Aquicludes or aquitards both above and below the aquifer
must be present to prevent the water from escaping the
pressure created on the aquifer will cause the water to rise
bull Does not always connote free-flowing surface discharge
bull Nonflowing artesian wells ndash pressure surface is below ground
level
bull Flowing artesian wells ndash pressure surface is above ground level
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1024
eol 11 1st Sem AY2011-12 91920
DNJ
Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1124
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1224
eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1024
eol 11 1st Sem AY2011-12 91920
DNJ
Flowing or Artesian Well Development
Flowing Artesian Wells
groundwater in confined system is
under enough pressure that no well
pumping is needed
The Dakota Aquifer System
Problems with groundwater withdrawal
bull Groundwater depletion or lowering of the water
table
ndash groundwater removed from an aquifer exceeds
the amount produced (ie demand gtgt supply)
ndash caused by
bull too much demand
bull too little recharge
Lowering of the Water Table
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1124
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1224
eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1124
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Saltwater contamination
ndash commonly occurs in many coastal areas where there is
a direct relationship between fresh groundwater andsalt groundwater
ndash since freshwater is less dense than salt water it f loats
on the salt water and forms a large lens-shaped body
that may extend to considerable depths below sea
level
ndash excessive pumping depletes the fresh groundwater
causing salt water to rise to a height where it can be
drawn into wells contaminating the freshwater supply
Saltwater Intrusion
Before
After
Animation
Problems with groundwater withdrawal
bull Groundwater contamination due to human activities
ndash most common source of pollution is sewage
(septic tanks inadequatebroken sewer systems
barnyard wastes etc)
ndash other sources include highway salt fertilizers
pesticides plus chemicals that may leak from
pipelines storage tanks landfills and holding
ponds
Reversal of Groundwater Flow Direction Reversal of Groundwater Flow Direction
Animation 1
Animation 2
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1224
eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1224
eol 11 1st Sem AY2011-12 91920
DNJ
Development of Contamination in Groundwater
Contaminant Plumes
If contaminants are soluble (completely dissolved in thewater) they move with the local groundwater flow
If contaminants are INSOLUBLE (do not dissolve or mix in the water)
Contaminant Plumes
Problems with groundwater withdrawal
bull Pore collapse
ndash because water cannot be compressed it holds thegrains of the rock or sediment apart
ndash extraction of water from pores eliminate thesupport holding the grains apart (air that replacesthe water can be compressed)
ndash grains pack more closely together permanentlydecreasing the porosity and permeability of therock
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1324
eol 11 1st Sem AY2011-12 91920
DNJ
Problems with groundwater withdrawal
bull Surface subsidence
ndash common in areas underlain by thick layers of
unconsolidated sediments
ndash as water pressure drops the weight of the
overburden is transferred to the sediment
ndash increased pressure packs the sediments tightly
together and the ground subsides
USGS scientist Joe Poland shows
the amount of ground
subsidence in the San Joaquin
Valley California between 1925
and 1977 due to fluidwithdrawal and soil
consolidation
httpwwwaegweborgimagesGeologic20Hazardssubsidence_Polandjpg
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1424
eol 11 1st Sem AY2011-12 91920
DNJ
bull In coastal areas land subsidence may even make the land surface sink
below sea level
bull The flooding in Venice Italy is due to land subsidence accompanying the
withdrawal of groundwater
bull The Leaning Tower of
Pisa (Italy) tilts because
the removal of groundwater caused its
foundation to subside
bull Land subsidence is most
severe for clay- and
organic-rich sediments
Nixa Missouri
A sinkhole collapse early morning of 13 Aug 2006 in Nixa Missouri is responsiblefor the disappearance of a garage and the Chevy Cavalier once parked inside The
sinkhole was initially estimated to be approximately 18 m in diameter and 23 m
deep
Guatemala Cit y
This 100 m-deep sinkhole
swallowed about a dozen homes on
23 Feb 2007 and is so far blamed in
the deaths of three peoplemdashtwoteenagers found floating in torrent
of sewage and their father who
was pulled from the chasm
Rainstorms and a ruptured sewer
main may have caused the
sinkhole After the collapse the
seemingly bottomless depths gave
off tremors sounds of flowing
water and the scent of sewage
httpnewsnationalgeographiccomnews200702070226-sinkhole-photohtml
Guatemala City
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1524
eol 11 1st Sem AY2011-12 91920
DNJ
Damaging effects of subsidence
bull Construction damage (buildings roads dams etc)
bull Alteration of landscape
bull Increased risk of flooding (lowered land surface)
bull Case study Pampanga Delta subsidence - initial
results of an 3-year research project funded DA-BAR
with initial funding from UP-CIDS
ndash People involved Rhodora Aparente Cherry Ringor
Nathaniel Baluda Kelvin Rodolfo Corazon Lamug
Fernando Siringan Cristina Remotigue Napoleon
Villanueva
1989
2001
Typical emerging well
Well rising outdoors
0
Legend
Roads
N
10 kmsLineaments
2219
38gt4
27
Benchmarks (DPWH 2001)
Emerging wells (cmyr)
406 cmyr
07110
33
176 cmyr3213
05 cmyr
23 cmyr
18 cmyr
0
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1624
eol 11 1st Sem AY2011-12 91920
DNJ
At Manilarsquos South Harbor mean sea level rose at about 2millimeters per year from 1902 to the early 1960rsquos
lt20 million litersper day (MLD)
250MLD
725
MLD
778 MLD
then started rising ten times as fast WHY
Global warming
Groundwater withdrawal
Another consequenceof population growth
Loosely packed sand
When wateris removedgrains crowdtogether alittle moreclosely
Volume issomewhat
reduced soland sinks alittle
But sand cannot compactvery muchFreshly
deposited claycontains muchmore water
and canshrink muchmore
Our delta sediments are very clayey
Subsidence from water withdrawal
Other East Asian Coastal Cities Sinkingfrom Excessive Groundwater Usage
SUBSIDENCELOCATION PERIOD Meters cmyear
Tokyo 1918-87 45 65Japan
Tokyo
Osaka 1934-68 28 82Japan
OsakaShanghai 1921-65 263 6China
Shanghai
Yun-Lin 1989-97 066 825Taiwan (Fishpond area)
Yun-Lin
Hanoi 1988-93 01-03 2-6Vietnam
Hanoi
Manila Bay 1964-2002 1 25
Manila
Bangkok 1980-90 05-1 5-10Thailand
Bangkok
Jakarta 1991-99 03-08 4-10Indonesia
Jakarta
Some other regions of subsidence from over-pumping of ground water
SUBSIDENCELOCATION PERIOD Meters cmyear
London England 1865-1995 065 05
Venice Italy 1952-69 0014 08-17
Nile Delta Egypt 1985-2000 008 05
Sta Clara Valley Calif 1920-67 40 85
Houston Texas 1943-73 23 74
New Orleans LA 1924-78 20 37
Mexico City Mexico 1970-73 015 50
Latrobe Valley Austral 1961-78 16 94
Geologic work of groundwater
bull Groundwater dissolves rock
ndash Groundwater is often mildly acidic
bull Contains weak carbonic acid
bull Forms when rainwater dissolves carbon dioxide
from the air and from decaying plants
ndash Caverns
bull Most caverns are created by acidic
groundwater dissolving soluble rock at or just
below the surface in the zone of saturation
Effects of Ground-Water Actionbull caves (or caverns) naturally formed underground
chamber
bull most caves develop when slightly acidic groundwater dissolves limestone along joints and
bedding planes opening up cavern systems as
calcite is carried away in solution
bull most caves probably are formed by ground water
circulating below the water table
H2O + CO2 + CaCO3 Ca++ + 2HCO3-
water carbondioxide
calcite inlimestone
calciumion
bicarbonateion
development of caves (solution)
development of flowstone and dripstone (precipitation)
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1724
eol 11 1st Sem AY2011-12 91920
DNJ
Geologic work of groundwater
bull Features found within caverns
ndash Composed of dripstone (travertine)
ndash Calcite deposited as dripping water evaporates
ndash Collectively they are called speleothems
ndash Includes stalactites (hanging from the ceiling)
and stalagmites (form on the floor of a cavern)
Chemical Weathering of Carbonates
bull Carbonic acid dissolves the calcite in limestoneliberating CO2 and dissolved Ca2+
bull Carbonates exposed to
rain continuously dissolve
bull This dissolution results
in caverns and karst
topography
bull stalactites icicle-like pendants of dripstone hanging from
cave ceilings generally slender and are commonly aligned
along cracks in the ceiling which act as conduits for
ground water
bull stalagmites cone-shaped masses of drip-stone formed on
cave floors generally directly below stalactites
Water moves along fractures and bedding planes inlimestone dissolving the limestone to form cavesbelow the water table
Falling water table allows cave system now greatlyenlarged to fill with air Calcite precipitation formsstalactites stalagmites and columns above thewater table
Catastrophic Subsidence Caves
Collapse intocaverns
Caverns producedby dissolution of limestone by acidicwaters
Acid produced when CO2 dissolves in water (carbonic acid)
Rock dissolves below water table
Dropping water table leaves behind caverns
Formation of Sinkholes
Weakened caveroofs collapse
Often due topumping of groundwater(water helpssupportoverlying rock)
Over 4000 sinkholes have formed since1900 in Alabama alone
Sinkholes
Winter Park Florida sinkhole (100m across x 34 m deep) formed1981
ldquoDecember giantrdquo sinkhole Alabama (130 m long x 46m
deep) formed 1972
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1824
eol 11 1st Sem AY2011-12 91920
DNJ
Original artwork by Gary Hincks
bull Composed of dripstone (travertine) calcite deposited as
dripping water evaporates
bull Collectively they are called speleothems
bull Stalactites (ceiling) and stalagmites (floor)
Cavern FeaturesldquoSoda strawsrdquo in Carlsbad Caverns National Park
Kartchner Caverns Arizona
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 1924
eol 11 1st Sem AY2011-12 91920
DNJ
Speleothems in Carlsbad Caverns National Park Geologic work of groundwater
bull Karst topography
ndash Landscapes that to a large extent have been shapedby the dissolving power of groundwater
ndash Some common features include
bull Irregular terrain
bull Sinkhole or sinks (formed by groundwater slowlydissolving the bedrock often accompanied bycollapse)
bull Striking lack of surface drainage (streams)
bull Caves and caverns
bull Tower karst
Karst topography
bull an area with many sinkholes and with cave
systems beneath the land surface
Karst topography is marked by underground cav es and numerous surface sinkholes A major river maycross the region but small surface streams generally disappear down sinkholes
Karst Sinkholes and Subsidence
Burnham
UP
MGB 200x
Subsidence Due to Karst
Natural developmentof sinkholes andunderground streamsin limestone areas is
a major factor in thesubsidence of certainareas of Baguio Cityincluding
Crystal CaveDominicanIrisanLourdes
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2024
eol 11 1st Sem AY2011-12 91920
DNJ
Ground subsidence in Crystal cave
(MGB 2006)
Satellite View mdash
Karst
Topography
Source Photograph copy NASA
Karstic
Area
Tower Karst
Southeastern China
Luoping Yunnan province China
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2124
eol 11 1st Sem AY2011-12 91920
DNJ
Arecibo Radio-telescope Puerto Rico
Restificar et al (2006)Protection of Karst in thePhilippinesActa
Carsologica 35 1 121 ndash
130
Restificar et al (2006) Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Restificaret al (2006)Protection of Karst in the PhilippinesActa Carsologica 35 1 121 ndash130
Chocolate Hills Bohol
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2224
eol 11 1st Sem AY2011-12 91920
DNJ
Coron Palawan
Saint Paul Limestone Cave Palawan
Limestone Cliffs - PalawanCallao Limestone caves Cagayan
Hundred Islands - Alaminos
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2324
eol 11 1st Sem AY2011-12 91920
DNJ
The geology of Hundred Islands Wawa Gorge ndash
Montalban Rizal
Hot Water Underground
bull hot springs springs in which the water is
warmer than human body temperature
bull water can gain heat in two ways while
underground
bull ground water may circulate near a magma
chamber or a body of cooling igneous rock
bull ground water may circulate unusually deep in the
earth
Geysers Intermittent hot
fountainscolumns of water
Hot Water Undergroundbull geyser a type of hot spring that periodically
erupts hot water and stream the water is
generally near boiling (100oC)
1
2
3
4
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig
832019 Groundwater Sept2011
httpslidepdfcomreaderfullgroundwater-sept2011 2424
eol 11 1st Sem AY2011-12 91920
Geothermal Energy
bull Electricity can be generated by harnessing
naturally occurring stream and hot water in
areas that are exceptionally hot underground(geothermal areas)
bull nonelectric uses of geothermal energy include
space heating as well as paper
manufacturing ore processing and food
preparation
Wallyrsquos and Deannarsquos Groundwater
Adventure
httpearthuwaterloocaoutreachmuseumwally-and-deannas-
groundwater-adventure
Isang Maikling KwentoSa buhay ng tubig