geology==tisis tisisan
TRANSCRIPT
-
8/7/2019 GEOLOGY==tisis tisisan
1/31
UNIVERSITY OF RIZAL SYSTEM
MORONG, RIZAL
COLLEGE OF ENGINEERING
ENGINEERING GEOLOGY
3-BSCE / GROUP 2
JOHN CLAYFORD EMATA
FATIMA CUBACUBCHERIL DEOCAREZA
JEMY DIMAGUILA
ARIANNE CEQUEA
RICHELLE DE LUNA
GREGORIE AGDA (5-BSCE)
ENGR. GEORGE VOLANTE
INSTRUCTOR
-
8/7/2019 GEOLOGY==tisis tisisan
2/31
2
ACKNOWLEDGEMENT
The researcher wishes to extend their heart felt acknowledgment and
appreciation to the following who gave their support in the realization of this work.
To Engr, George Volante, Instructor, Engineering Geology, for giving this work
and also for the encouragement to finish this work.
To 3-BSCE, SY 2010-2011, for giving special assistance to make this work possible.
To the researchers family and friends, who in some other ways inspired and gave
moral support in pursuing this study.
To all authors of books, magazines and other sources of information, their existence
makes the research complete.
And above all, to the Omnipotent God, for giving strength, the guidance and sound
mind and body to the researcher to make this study possible.
GROUP 2
-
8/7/2019 GEOLOGY==tisis tisisan
3/31
3
DEDICATION
To Almighty God,
to their teacher and classmates
to their fathers and mothers,
to their lolos and lolas
to their brothers and sisters, nieces and nephews,
to their friends
who shared their
LOVE and SUPPORT.
This study
is dedicated to them.
GROUP 2
-
8/7/2019 GEOLOGY==tisis tisisan
4/31
4
OBJECTIVES
y To learn some what are the different phenomenon on the surface of the
earth and even beneath the earth surface.
y To know how these phenomenon happens.y To know how to avoid or to prevent these phenomenon through common
solutions and through the solution of Civil Engineers.
y To find out what are the different resources that can be found on the earth.
y To know what are the significance of these phenomenon and resources in
line with the course Bachelor of Science in Civil Engineering.
INTRODUCTION
Geology is the study of the earth, meaning it is the science that deals with the
dynamics and physical history of the earth, the rocks of which it is composed, and the
physical, chemical, and biological changes that the earth has undergone or is
undergoing.
Geology is very important in our lives especially in the course of Civil
Engineering, because the structures we built and lived in, we studied in and the place
we go are made in the surface and or beneath of the earth so it is very significant that
we should study the earths behavior for us to know the nature of the earth to avoid or
prevent any catastrophe due to natural calamities such as mass wasting and floods, etc.
Also we should have the knowledge about the resources we can get in the earth that
can be use as materials in constructing structures or even resources we need in our
daily lives like water and the cost it takes to have it.
In connection with the Course Civil Engineering, the following topics will be
discussed for us to know the basics about these phenomenon and resources for these
are all factors in line with the said course:
y Mass Wasting
y Underground Water
y Geological Resources
y Streams
y Floods
-
8/7/2019 GEOLOGY==tisis tisisan
5/31
5
GRAVITY-DRIVEN TRANSPORT - MASS
MASS WASTING
When a material on a hillside has
weathered, it is likely to move down slope
because of the pull of gravity. Soil or rock movingin at the earths surface is called mass wasting.
Mass wasting, also known as slope
movement or mass movement, is the geomorphic
process by which soil, regolith, and rock move
down slope under the force of gravity. Types of
mass wasting include creep, slides, flows,
topples, and falls, each with its owncharacteristic features, and taking place over
timescales from seconds to years. When the gravitational force acting on a slope
exceeds its resisting force, slope failure (mass wasting) occurs. The slope material's
strength and cohesion and the amount of internal friction between materials help
maintain the slopes stability and are known collectively as the slope's shear strength.
The steepest angle that a cohesionless slope can be maintain without losing its
stability is known as its angle of repose. When a slope possesses this angle, its
shear strength perfectly counterbalances the force of gravity acting upon it.
Mass wasting may occur at a very slow rate, particularly in areas that are very dry or
those areas that receive sufficient rainfall such that vegetation has stabilized the
surface. It may also occur at very high speed, such as in rock slides or landslides, with
disastrous consequences, immediate and delayed, resulting from the formation of the
landslide dams.
Landslide is the best known type of mass wasting. Landslides destroy towns and kill
people.
-
8/7/2019 GEOLOGY==tisis tisisan
6/31
6
CLASSIFICATION OF MASS WASTING
Rate of Movement
A landslide clearly involves rapid movement. Just as clearly, movement of soil at a
rate of less than a centimeter a year is slow movement. Between these extremes is awide range of velocities.
Type of Movement
Mass wasting processes are usually distinguished on the basis of whether the
descending mass started as bedrock or as debris. The term debris, as applied to mass
wasting processes, means any consolidated material at the earth surface, such as soil
and rock fragments of any size.
Type of Movement
In general, the type of movement in mass wasting can be classified as mainly flow,
slide, or fall. A flow implies that the descending mass is moving down slope as a
viscous fluid. Slide means the descending mass remains relatively coherent, moving
along or more well-defined surfaces. A fall occurs when material free-falls or bounces
down a cliff. Two kinds of slip are translational slide and rotational slide. Translational
slide, the descending mass moves along a plane approximately parallel to the slopeof the surface. A rotational slide involves movement along a curved surface, the upper
part move downward while the lower part moves outward.
-
8/7/2019 GEOLOGY==tisis tisisan
7/31
7
CONTROLLING FACTORS IN MASS WASTING
1. The slopes were exceptionally steep
2. The relief (the vertical distance between valley floor and mountain summit)was great, allowing the mass to pick up speed and momentum.
3. Water and ice not only added weight to the mass of debris but also acted as
lubricants.
4. Abundant loose rock and debris were available in the course of the slide.
5. Where the slide began, there were no plants with roots to anchor loose
material on the slope.
6. The area is earthquake prone.
Another factor that control in mass wasting is climate. Which influences how
much and what kinds of vegetation grow in an area and what type of weathering occurs.
Infrequent but heavy rainfall aids mass wasting because it quickly saturates debris that
lacks the protective vegetation found in wetter climates.
Gravity
Gravity is the driving force for mass wasting. The length of the vertical arrow isproportional to the force-the heavier the material, the longer the arrow. The effect of
gravity is resolvable into two component forces, indicating by the black arrows. One, the
normal force, is perpendicular to the slope and its value indicates the blocks ability to
stay in place because of frictional considerations. The other, called the shear force, is
parallel to the slope, and indicates the blocks ability to move. The length of the arrows
-
8/7/2019 GEOLOGY==tisis tisisan
8/31
8
is proportional to the strength of each force. The steeper the slope (and the heavier the
block), the greater the shear force and the greater the tendency of the block to slide. If
friction is greater than the shear force, the block will not move. The resistance to
movement or deformation of the debris on a hillside that debris is its shear strength.
Shear strengh is also related to the normal force.
Gravity is the physical force of attraction between any two objects in the
universe. One of the four fundamental forces (the others are electromagnetism and the
strong and weak forces), gravity affects all objects on Earth. From the largest mountains
to the smallest grains of sand, gravity pulls everything in a direction toward the center of
the planet. As long as material remains on a flat surface, one that is parallel to Earth's
surface, gravity will not cause it to move. When material is on a slope and conditionsare right, however, gravity will cause it to fall, slide, flow, slump, or creep downward.
That downhill movement of soil, rocks, mud, and other debris can be either slow
or fast. Large amounts that move quickly are perhaps the most widespread geologic
hazard. Each year in the United States, ground failures of various sorts cause between
twenty-five and fifty deaths and roughly $1.5 billion in economic loss. In less-developed
nations, where poorly constructed buildings house many people in areas prone to
ground failures, the death tolls and amount of property damage are much higher.
Water
Water is a critical factor in mass wasting. When debris is saturated with water, it
becomes heavier and more likely to flow down slope. The added gravitational shear
force from the increased weight, however, is probably less important than the reducyion
in shear strength. This is due to increased pore pressure in which water forces grains of
debris apart.
Water is an important agent in the process of mass wasting. Water will either
help hold material together, increasing its angle of repose, or cause it to slide downward
like a liquid. In mass wasting, water acts as either glue or a lubricant. Small amounts of
water can strengthen material. Slightly wet particles have a higher angle of repose
-
8/7/2019 GEOLOGY==tisis tisisan
9/31
9
because the thin film of water that exists between the particles increases the tension
holding them together. An example of this action can be seen in sand. Dry sand does
not stick together very well. A sand castle made of dry sand will not stand very high. Yet
one made with slightly moist sand will. If too much water is added, though, the sand will
become waterlogged and the castle will collapse. When material becomes saturated
with water, the angle of repose is reduced to a small degree and the material tends to
flow like a liquid. This occurs because the excess water completely surrounds the
particles in the material, eliminating the frictional contact between the particles that
holds them together.
Paradoxically, a small amount of water in soil can actually prevent downslope
movement. When water does not completely fill the pore spaces between the grains ofsoil, it forms a thin film around each grain. Loose grains adhere to one another because
of the surface tension created by the film of water and shear strength increases.
Surface tension of water between sand grains is what allows you to build a sand castle.
The sides of the castle can be steep or even vertical because surface tension holds the
moist sand grains in place.
Similarly, as the amount of water in debris increases, rate of movement tends to
increase. Damp debris may not move at all, whereas moderately wet debris movesslowly down slope. Slow types of mass wasting, such as creep, are generally
characterized by a relatively low ratio of water to debris.
COMMON TYPES OF MASS WASTING
Creep
Creep is a very slow down slope movement of soil or unconsolidated debris.
Shear force, over time, are only slightly greater than the shear strength. Two factors that
contribute significaly to creep are water in the soil and daily cycles of freezing and
thawing. As we have said, water-saturated ground facilitates movement of soil downhill.
-
8/7/2019 GEOLOGY==tisis tisisan
10/31
10
Although creep does take place in year-round warm climates, the process is more
active where the soil freezes and thaws during part of the year.
Debris flow
A mixture of water and clay, silt, sand, and rock fragments that flows rapidly
down steep slopes. The general term debris flow is used for mass wasting in which
motion is taking place throughout the moving mass. The common varieties earthflow,
mudflow, and debris avalanche are described in this section.
EarthflowThe downward movement of water-saturated, clay-rich soil on a moderate slope.
In an earthflow, debris moves downslope as a viscous fluid; the process can be slow or
rapid. Earthflows usually occur on hillsides that have a thick cover of debris, often afterheavy rains have saturated tha soil. A landslide may be entirely an earthflow, with
debris particles moving past one another roughly parallel to the slope.
Humans can trigger earthflows by adding too much water to soil from septic tank
systems or by overwatering lawns. Earthflows, like other kinds of landslides, can be
triggered by caused by waves breaking along shorelines or streams eroding and
steepening the base of a slope.
Bulldozers can undercut the base of a slope more rapidly than wave erosion, and
such oversteepining of slops by human activity has caused many landslides. Unless
careful engineering measures are taken at the time a cut is made, roadcuts or platforms
carved into hillsides for houses may bring about disaster
Solifluction And PermafrostOne variety of earthflow is usually associated with colder climates. Solifluction is
the flow of water-saturated debris over impermeable material. Because theimpermeable material beneath the debris prevents water from draining freely, the debris
between the begetetion cover and the impermeable material becomes saturated. The
impermeable material beneath the saturated soil can be either impenetrable bedrock or,
as is more common, permafrost, ground that remains frozen for many years.
-
8/7/2019 GEOLOGY==tisis tisisan
11/31
11
Solifluctin is not the only hazard associated with permafrost. Great expances of
flat terrain arctic and subarctic climates become swampy during the summer because of
permafrost, making overland travel very difficult.
MudflowA mixture primarily made of the smallest silt and clay particles and water that has
the consistency of newly mixed concrete and that flows quickly down slopes. A mudflow
is a flowing mixture of debris and water, usually moving down a channel. It can be
visualized as a stream with the consistency of a thick milkshake. Usually, after a heavy
rainfall slurry of debris and water forms and begins moving down a slope. Most
mudflows quickly become channeled into valleys. They then move down valley like a
stream except that, because of the heavy load of debris, they are more viscous.. Mudmoves more slowly than a stream but, because of its high viscosity, can transport
boulders, automobiles, and even locomotives. Houses in the path of a mudflow will be
filled with mud, if not broken apart and carried away.
Mudflows frequently occur on young volcanoes that relittered with ash. Or the
water can come from glaciers that are melted by lava or hot pyroclatic debris, as
occurred at Mount St. Helens in 1980 and at Colombias Nevedo del Ruiz in 1985.
Which cost 23,000 lives.
Debris AvalancheSome geologists have suggested that in very rapidly moving rock avalanches, air
trapped under the rock mass creates an air cushion tha reduces friction. This could
explain why some landslides reach speeds of several hundred kilometers per hour.
Rockfalls And Rockslide
RockfallWhen a block of bedrock breaks off and falls freely or bounces down a cliff, it is a
rockfall. Cliffs may from naturally by the undercutting action of a river, wave action. Or
glacial erosion. Highway or other construction projects may also oversteepen slopes.
Bedrock commonly has cracks or other planes of weakness such as foliation or
-
8/7/2019 GEOLOGY==tisis tisisan
12/31
12
sedimentary bedding planes. Block s of rock will break off along these planes. In colder
climates rock is effectively broken apart by frost wedging.
Rockslide
A rockslide is, as term suggest, the rapid sliding of a mass od bedrock along an
inclined surface of weakness, such as a bedding plane, a major fracture in the rock, or a
foliation plane. Some rockslide travel only a few meters before halting at the base of a
slope. In country with high relief, however, a rockslide may be tavel a hundreds or
thousands of meters before reaching a valley floor. If movement becomes very rapid,
the rockslide may break up and become a rock avalanche. A rock avalanche is a very
rapidly moving, turbulent mass of broken-up bedrock. Movement is a rock avalanche is
flowage on a grand scale.
Debris Slides And Debris FallsAs the names suggest, debris slides and debris falls behave similarly to
rockslides and rockfall, except that they involve debris that moves as a coherent mass.
A debris fall is a free-falling mass of debris.a deris slides is coherent mass of debris
moving along a well-defined surface.
PREVENTING LANDSLIDE
Preventing Mass Wasting Of Debris
Usually mass movement of debris can be prevented. Proper engineering is
essential when the natural environment of hillside is altered by construction. Some
primitive measures can be taken during construction. A retaining wall is usually built
where a cut has been made in the slope, but this alone is seldom as effective a
deterrent to down-slope movement as people hope. If, in addition, drain pipes are put
through the retaining wall and into the hillside, water can percolate through and drain
away rather than collecting in the debris behind the wall. Without drains, excess water
results in decreased shear strength and the whole soggy mass can burst through the
wall.
-
8/7/2019 GEOLOGY==tisis tisisan
13/31
13
Another practical preventive measure is to avoid oversteeping the slope. Rode
cuts constructed in this way are usually reseed with rapidly growing grass or plants
whose roots help anchor the slope. A vegetation cover also minimizes erosion from
running water.
Preventive Rockfalls And Rockslide On
Highway
Rockfalls and rockslide are major problem on
highway built through mountainous country.
Steep slopes and cliffs are created when road
cuts are blasted and bulldozed into mountain
sides. Various techniques are used to prevent
rockslide. By doing a detailed geologic study of an area before a road is built, builders
might avoid a hazard by choosing the least dangerous route for the road. If a road cut
must be made through bedrock that appears prone to sliding, all the rock that might
slide could be removed. In some instances, slopes prone to rock sliding have been
sitched in place by the technique.
MASS WASTING AND CIVIL ENGINEERING: THEIR CONNECTION
-
8/7/2019 GEOLOGY==tisis tisisan
14/31
14
In building structures, it requires a focused study before we build it for the safety
and convenience of all people.
Like in building houses we must consider the place. Example near in the
mountain, we must consider the possibilities happen in that place, one of that is rockfallor rockslide or any other kind of mass wasting.
GROUND WATER
Ground water is water located beneath the ground surface in soil pore spaces
and in the fractures of rock formations.
Groundwater comes from rain, snow, sleet, and hail that soaks into the ground.
The water moves down into the ground because of gravity, passing between particles of
soil, sand, gravel, or rock until it reaches a depth where the ground is filled, or
saturated, with water.
Importance
1. Part of the Hydrologic Cycle
Groundwater can be a long-term 'reservoir' of the natural water cycle (with residence
times from days to millennia), as opposed to short-term water reservoirs like the
atmosphere and fresh surface water (which have residence times from minutes to
TheWat
erCycl
e
-
8/7/2019 GEOLOGY==tisis tisisan
15/31
15
years). The figure shows how deep groundwater (which is quite distant from the surface
recharge) can take a very long time to complete its natural cycle.
2. 25% of all the fresh water on Earth
3. Important Environmental Issues
(Example of Impact of Urban Development on Groundwater Systems)
EARTHS INVENTORY
OF WATER
25% of all the fresh
water on Earth
BEFORE AFTER
-
8/7/2019 GEOLOGY==tisis tisisan
16/31
16
Basic Concepts
Water Table is the depth at which soil pore spaces or fractures and voids in rock
become completely saturated with water
It is the boundary between the unsaturated (vadose) zone and saturated zone of an
aquifer
AQUIFERS
An aquifer is a geologic formation,
group of formations, or part of a formation
that contains sufficient saturated
permeable material to yield significant
quantities of water to springs and wells
(Groundwater)
In other words, an aquifer is a
geological material that can store and transmit large quantities of groundwater
Aquifer Types
1. Unconfined shallow aquifers at Earths surface, usually made of sand and
gravel, no capping impermeable layer.
-
8/7/2019 GEOLOGY==tisis tisisan
17/31
17
2. Confined deep bedrock aquifer
(sandstone, limestone) sandwiched
between two impermeable layers
(shales).
Groundwater can move through aquifers until it reaches
an opening to the surface. In a seep, the water reaches the
surface over a large area. In a spring, water flows from the
earth at a small point. Because of the pressure of the water
Unconfined A uifer
Confined Aquifer
-
8/7/2019 GEOLOGY==tisis tisisan
18/31
18
above it, water in confined aquifers is generally under high
pressure and can result in the production of an artesian
spring. Springs and seeps will only continue to flow as long
as the water table is higher than they are. Because of
movement of water, the location of the recharge zone may
be far from the location of seeps and springs.
Relationship of Ground water to the Civil Engineering Field
Geotechnical engineering is an area of civil engineering concerned with the
rock and soil that civil engineering systems are supported by. Knowledge from the fields
of geology, material science and testing, mechanics, and hydraulics are applied by
geotechnical engineers to safely and economically design foundations, retaining walls,and similar structures. Environmental concerns in relation to groundwater and waste
disposal have spawned a new area of study called geoenvironmental engineering
where biology and chemistry are important.
Water resources engineering is concerned with the collection and management
of water (as a natural resource). As a discipline it therefore combines hydrology,
environmental science, meteorology, geology, conservation, and resource
management. This area of civil engineering relates to the prediction and management of
both the quality and the quantity of water in both underground (aquifers) and above
ground (lakes, rivers, and streams) resources. Water resource engineers analyze and
model very small to very large areas of the earth to predict the amount and content of
water as it flows into, through, or out of a facility.
Sources of Groundwater Contamination
-
8/7/2019 GEOLOGY==tisis tisisan
19/31
19
Environmental Impacts of Ground Water Extraction
y Lowering of the water table
y Reversal of Groundwater Flow Direction
y Saltwater Intrusion
y Land Subsidence
Why do we have to Preserve and Protect our Ground water resources?
Groundwater makes up about twenty percent of the world's fresh water supply,
which is about 0.61% of the entire world's water, including oceans and permanent ice.
Global groundwater storage is roughly equal to the total amount of freshwater stored in
the snow and ice pack, including the north and south poles. This makes it an important
resource which can act as a natural storage that can buffer against shortages of surface
water, as in during times of drought.
RESOURCES
A resource is any physical or virtual entity of limited availability that needs to be
consumed to obtain a benefit from it. In most cases, commercial or even non-
commercial factors require resource allocation through resource management. There
two types of resources; renewable and non renewable.Value of resource
The purely economic value of a resource is controlled by supply and demand.
This is, however, a narrow perspective on resources as there are many things that
cannot be measured in money.
Natural resources like forests, mountains etc. are considered beautiful so they
have aesthetic value. Resources also have an ethical value as well, because it is widely
recognized that it is our moral duty to protect and conserve them for the future
generations (see sustainable development).
Resources have three main characteristics: utility, quantity (often in terms of
availability), and consumption. However, this definition is not accepted by some, for
example deep ecologists who believe that non-human elements are independent of
human values.
-
8/7/2019 GEOLOGY==tisis tisisan
20/31
20
Types of resources
Natural resources
Natural resources are derived from the environment. Many of them are essential for
our survival while others are used for satisfying our needs. Natural resources may be
further classified in different ways; on the basis of origin, resources may be divided into:
y Biotic - Biotic resources are those obtained from the biosphere. Forests and
their products, animals, birds and their products, fish and other marine organisms
are important examples. Minerals such as coal and petroleum are also included
in this category because they were formed from decayed organic matter.
y Abiotic - Abiotic resources comprise non-living things. Examples include land,
water, air and minerals such as gold, iron, copper, silver etc.
On the basis of the stage of development, natural resources may be called:y Potential Resources - Potential resources are those that exist in a region and
may be used in the future. For example, mineral oil may exist in many parts of
India having sedimentary rocks, but until the time it is actually drilled out and put
into use, it remains a potential resource.
y Stock are the materials in the environment which have the potential to satisfy
human needs but do not have the appropriate technology to access them. For
example, hydrogen and oxygen are two inflammable gases present in water, but
we do not have the technology to use them from water.
y Reserved Resources are the subset of stock, where use has not yet been
started and are saved for future use.
y Actual resources are those that have been surveyed, their quantity and quality
determined, and are being used in present times. For example, petroleum and
natural gas obtained from the Mumbai High Fields. The development of an actual
resource, such as wood processing depends upon the technology available and
the cost involved. That part of the actual resource that can be developed
profitably with available technology is called a reserve.
On the basis of renewability, natural resources can be categorized into:
y Renewable Resources - Renewable resources are those that can be
replenished or reproduced easily. Some of them, like sunlight, air, wind, etc., are
-
8/7/2019 GEOLOGY==tisis tisisan
21/31
21
continuously available and their quantity is not affected by human consumption.
Many renewable resources can be depleted by human use, but may also be
replenished, thus maintaining a flow. Some of these, like agricultural crops, take
a short time for renewal; others, like water, take a comparatively longer time,
while still others, like forests, take even longer.
y Non-renewable Resources - Non-renewable resources are formed over very
long geological periods. Minerals and fossils are included in this category. Since
their rate of formation is extremely slow, they cannot be replenished once they
are depleted. Out of these, the metallic minerals can be re-used by recycling
them, but coal and petroleum cannot be recycled.
On the basis of distribution, natural resources can be classified into:
Ubiquitous-are those that can be found everywhere. For example-air, light, wateretc.
Localised-are those that can be found only in certain parts of the world. For
example-copper and iron ore, thermal power plant etc.
On the basis of ownership, resources can be classified into: individual, community,
national, and international Individual resources:
Human resources
Human beings are also considered to be resources. The term Human Resources
can also be defined as the skills, energies, talents, abilities and knowledge that are
used for the production of goods or the rendering of services.
In a project management context, human resources are those employees
responsible for undertaking the activities defined in the project plan.
Tangible / intangible resources
Resources may be split into tangible and intangible resources. Tangible
resources are those resources like equipment, vehicles which have actual physical
existence; whereas intangible resources are things like corporate images, brands and
patentes that are present but cannot be grasped or contained.
Resource use and sustainable development
Many resources cannot be consumed in their original form. They have to be
processed in order to change them into more usable commodities. This is known as
-
8/7/2019 GEOLOGY==tisis tisisan
22/31
22
resource development. With increasing population, the demand for resources has also
increased. However, there is a difference in distribution of resources between regions or
countries. Developed countries use more natural resources than developing countries
There are several problems related to the usage of resources:
y Resource depletion
y Environmental degradation
y Tragedy of the commons
y Resource curse
y Over-consumption
Natural resources include all those materials which can be utilized by man to his
advantage. The basic needs of life include air, water, sunlight, minerals and habitat. Allthese are of cosmic origin and are not created by man and therefore, are called natural
resources. The natural resources occur in all the three divisions of biosphere
(lithosphere, atmosphere and hydrosphere)
TYPES OF NATURAL RESOURCES:
(a) Inexhaustible Resources: The resources which are not likely to be exhausted are
called inexhaustible resources.
E.g. Air, clay, sand, water and solar energy.
These are not likely to be exhausted by human use.
(b) Inexhaustible Resources: The natural resources which are present in limited
amount are bound to get exhausted if not properly managed are called exhaustible. The
exhaustible resources may be renewable and non- renewable.
(i) Renewable Resources: These include resources which can be regenerated even if
partially destroyed.
e.g. plants and animal resources, water and certain soil types, minerals and gases
(CO2, O2) are renewable.Some of these materials are constantly renewed in nature, others can be
reclaimed or purified and used again and again. All types of resources require
management and conservation.
-
8/7/2019 GEOLOGY==tisis tisisan
23/31
23
(ii) Non-renewable Resources: The non-renewable resources once used, are lost
forever as they are not restored.
E.g Natural gas, coal, petroleum, mineral oils, metals, minerals and stones.
These materials were created millions of years ago under the earth's surface.
These materials will never be created once finished.
Importance of Natural Resources:
The natural resources play an important role in our lives. The importance of
natural resources in our lives can be viewed from the following points:
(i) The most important use of land to man is that it provides space forwork. All activities of man take place on land whether it is agriculture,
transport, industry, housing, mining etc.(ii) Most of the passengers and goods are transported by land transportmeans.
(iii) Land provides a large number of minerals like coal, petroleum, iron,copper, gold, mica etc.
(iv) Air is an integral component of environment. Man makes variety ofuses of air such as breathing, burning
(v) Oxygen in air is required for breathing by all human beings andanimals.
(vi) The sound waves travel in air, so we can hear easily.(vii) Wind energy can be harnesses from moving air called wind.
(viii) Around 71% of the earth's surface is covered with water. All life isimpossible without it. It is used for household purposes, irrigation,transport, for producing tidal energy etc.
(ix) Water is also used in many industries like textiles, iron and steel, paperetc.
(x) Tides result in rise and fall of sea water which can be harnessed toproduce electricity.
(xi) Whatever we look around us is because of light. The sun is the majorsource of light on earth.
(xii) The process of photosynthesis also needs light. Animals also needlight to grow.
(xiii) Sun's light can be converted into energy called solar energy.
Introduction on importance of mineral resources:
The minerals occurs naturally in the earths crust, however, their distribution is
not even. Minerals essential to our industrialised society and daily life are non-
renewable resources. Due to the increase in industrialisation, the consumption of
-
8/7/2019 GEOLOGY==tisis tisisan
24/31
24
minerals has increased tremendously all over the world. The minerals now is short
supply will probably be exhausted within next 20 to100 years. Even the minerals which
are relatively plentiful will become extremely expensive because of the depletion of
large, rich and easily accessible deposits of these metals.
Minerals can be metallic e.g. iron, copper, gold, etc. Or non metallic, e.g. sand, stone,
salt, phosphate, etc. Let us see importance and uses of mineral resources
Importance and Uses of Minerals:
Extraction processing and disposal of minerals have negative effects on
environment. Mining not only disturbs and damages the land, but also pollutes the soil,
water and air. The land that has been destroyed due to mining is known as derelict land
or mine spoil. Such derelicts land can be reclaimed or restored to a semi-natural
condition by re- vegetation to prevent further degradation, and to make the land
productive for other purposes.
Importance of Resources in Civil Engineering
In constructing structures or infrastructures, a civil engineer must consider the
resources as one factor for his materials to be use in constructing them. And resources
have a big role in ones life. Thus, a civil engineer must know its importance because allconstruction materials are made out from our resources. Not only the uses or on how to
use those materials but also to know where it comes from. A civil engineer must also be
aware, concerning the limitations of our resources, the advantages and disadvantages
that can affect by overusing or abusing our natural resources.
STREAM
A stream is a body of water with a current, confined within a bed and stream
banks. Depending on its locale or certain characteristics, a stream may be referred to as
a branch, brook, beck, burn, creek, gill (occasionally ghyll), kill, lick, rill, river, syke,
bayou, rivulet, streamage, wash, run orrunnel.
-
8/7/2019 GEOLOGY==tisis tisisan
25/31
25
Streams are important as conduits in the water cycle, instruments in groundwater
recharge, and corridors for fish and wildlife migration. The biological habitat in the
immediate vicinity of a stream is called a riparian zone. Given the status of the ongoing
Holocene extinction, streams play an important corridor role in connecting fragmented
habitats and thus in conserving biodiversity. The study of streams and waterways in
general is known as surface hydrology and is a core element of environmental
geography.
Types
y River - A large natural stream, which may be a waterwayy Creeky Tributary - A contributory stream, or a stream which does not reach the sea but
joins another river (a parent river). Sometimes also called a branch or fork.y Brook - A stream smaller than a creek, especially one that is fed by a spring or
seep. It is usually small and easily forded. A brook is characterized by itsshallowness and its bed being composed primarily of rocks.
Parts of a stream
y Bar- A shoal that develops at the mouth of a river as sediment carried by theriver is deposited as the current slows or is impedded by wave action. TheTemperance River on Lake Superior's north shore is so named because it is oneof the few rivers flowing into the lake that does not have a bar at its mouth.
y Spring - The point at which a stream emerges from an underground coursethrough unconsolidated sediments or through caves. A stream can, especiallywith caves, flow aboveground for part of its course, and underground for part ofits course.
y Source - The spring from which the stream originates, or other point of origin of astream.
y Headwaters - The part of a stream or river proximate to its source. The word ismost commonly used in the plural where there is no single point source.
y Confluence - The point at which the two streams merge. If the two tributaries areof approximately equal size, the confluence may be called a fork.
y
Run - A somewhat smoothly flowing segment of the stream.y Pool - A segment where the water is deeper and slower moving.y Riffle - A segment where the flow is shallower and more turbulent.y Channel - A depression created by constant erosion that carries the stream's
flow.y Floodplain - Lands adjacent to the stream that are subject to flooding when a
stream overflows its banks.y Stream bed - The bottom of a stream.
-
8/7/2019 GEOLOGY==tisis tisisan
26/31
26
y Gauging station - A point of demarkation along the route of a stream or river,used for reference marking or water monitoring.
y Thalweg - The river's longitudinal section, or the line joining the deepest point inthe channel at each stage from source to mouth.
y Wetted perimeter- The line on which the stream's surface meets the channel
walls.y Nickpoint - The point on a stream's profile where a sudden change in stream
gradient occurs.y Waterfall orcascade - The fall of water where the stream goes over a sudden
drop called a nickpoint; some nickpoints are formed by erosion when water flowsover an especially resistant stratum, followed by one less so. The streamexpends kinetic energy in "trying" to eliminate the nickpoint.
y Mouth - The point at which the stream discharges, possibly via an estuary ordelta, into a static body of water such as a lake or ocean.
Sources
Streams typically derive most of their water from precipitation in the form of rain
and snow. Most of this water re-enters the atmosphere by evaporation from soil and
water bodies, or by the evapotranspiration of plants. Some of the water proceeds to sink
into the earth by infiltration and becomes groundwater, much of which eventually enters
streams. Some precipitated water is temporarily locked up in snow fields and glaciers,
to be released later by evaporation or melting. The rest of the water flows off the land as
runoff, the proportion of which varies according to many factors, such as wind, humidity,
vegetation, rock types, and relief. This runoff starts as a thin film called sheet wash,
combined with a network of tiny rills, together constituting sheet runoff; when this water
is concentrated in a channel, a stream has its birth.
FLOOD
A flood is an overflow of an expanse of water that submerges land. The EUFloods directive defines a flood as a temporary covering by water of land not normallycovered by water. In the sense of "flowing water", the word may also be applied to theinflow of the tide. Flooding may result from the volume of water within a body of water,such as a river or lake, which overflows or breaks levees, with the result that some ofthe water escapes its usual boundaries
-
8/7/2019 GEOLOGY==tisis tisisan
27/31
27
While the size of a lake or other body of water will vary with seasonal changes inprecipitation and snow melt, it is not a significant flood unless such escapes of waterendanger land areas used by man like a village, city or other inhabited area.
Floods can also occur in rivers, when flow exceeds the capacity of the river
channel, particularly at bends or meanders. Floods often cause damage to homes andbusinesses if they are placed in natural flood plains of rivers. While flood damage canbe virtually eliminated by moving away from rivers and other bodies of water, since timeout of mind, people have lived and worked by the water to seek sustenance andcapitalize on the gains of cheap and easy travel and commerce by being near water.That humans continue to inhabit areas threatened by flood damage is evidence that theperceived value of living near the water exceeds the cost of repeated periodic flooding.
Principal types and causes
Riverine
y Slow kinds: Runoff from sustained rainfall or rapid snow melt exceeding thecapacity of a river's channel. Causes include heavy rains from monsoons,hurricanes and tropical depressions, foreign winds and warm rain affecting snowpack. Unexpected drainage obstructions such as landslides, ice, or debris cancause slow flooding upstream of the obstruction.
y Fast kinds: include flash floods resulting from convective precipitation (intensethunderstorms) or sudden release from an upstream impoundment createdbehind a dam, landslide, or glacier.
Estuarine
y Commonly caused by a combination of sea tidal surges caused by storm-forcewinds. A [storm surge], from either a tropical cyclone or an extratropical cyclone,falls within this category.
Coastal
y Caused by severe sea storms, or as a result of another hazard (e.g. tsunami orhurricane). A storm surge, from either a tropical cyclone or an extratropicalcyclone, falls within this category.
Catastrophic
y Caused by a significant and unexpected event e.g. dam breakage, or as a resultof another hazard (e.g. earthquake or volcanic eruption).
Muddy
y A muddy flood is generated by run off on crop land.
-
8/7/2019 GEOLOGY==tisis tisisan
28/31
28
A muddy flood is produced by an accumulation of runoff generated on cropland.Sediments are then detached by runoff and carried as suspended matter or bed load.Muddy runoff is more likely detected when it reaches inhabited areas.
Muddy floods are therefore a hill slope process, and confusion with mudflows produced
by mass movements should be avoided.
Other
y Floods can occur if water accumulates across an impermeable surface (e.g. fromrainfall) and cannot rapidly dissipate (i.e. gentle orientation or low evaporation).
y A series of storms moving over the same area.y Dam-building beavers can flood low-lying urban and rural areas, often causing
significant damage.
Effects
Primary effects
y Physical damage - Can damage any type of structure, including bridges, cars,buildings, sewerage systems, roadways, and canals.
y Casualties - People and livestock die due to drowning. It can also lead toepidemics and waterborne diseases.
Secondary effects
y Water supplies - Contamination of water. Clean drinking water becomes scarce.y Diseases - Unhygienic conditions. Spread of water-borne diseases.y Crops and food supplies - Shortage of food crops can be caused due to loss of
entire harvest.[4] However, lowlands near rivers depend upon river silt depositedby floods in order to add nutrients to the local soil.
y Trees - Non-tolerant species can die from suffocation. [5]
Tertiary/long-term effects
Economic - Economic hardship, due to: temporary decline in tourism, rebuilding costs,food shortage leading to price increase, etc.
Flood Control
y Levees
o A levee, leve, dike (ordyke), embankment, floodbank orstopbank is
a natural or artificial slope or wall to regulate water levels. It is usually
earthen and often parallel to the course of a river or the coast.
-
8/7/2019 GEOLOGY==tisis tisisan
29/31
29
y Bunds
o Bunding, also called a bund wall, is the area within a structure designed
to prevent inundation or breaches of various types
y Reservoirs
o artificial lake is used to store water. Reservoirs may be created in rivervalleys by the construction of a dam or may be built by excavation in the
ground or by conventional construction techniques such a brickwork or
cast concrete.
y Weirs
o small overflow dam used to alter the flow characteristics of a river or
stream. In most cases weirs take the form of a barrier across the river that
causes water to pool behind the structure (not unlike a dam), but allow
water to flow over the top.
y Sandbagso A sandbag (floodbag) is a sack made of hessian/burlap, polypropylene or
other materials that is filled with sand or soil and used for such purposes
as flood control, military fortification, shielding glass windows in war
zones and ballast.
y Coastal Defences
o Sea walls - a seawall (also written as sea wall) is a form of hard and
tough coastal defence constructed on the inland part of a coast to reduce
the effects of strong waves.
o Beach Nourishment - also referred to as beach replenishment
describes a process by which sediment (usually sand) lost through long
shore drift or erosion is replaced from sources outside of the
eroding beach.
o Barrier Islands. - Chains of barrier islands can be found along the world's
coastlines of different settings, suggesting that they can form and be
maintained in a variety of environmental settings. Numerous theories have
been given to explain their formations.
Benefits
Recharging ground water
Making soil more fertile and providing nutrients in which it is deficient.
Flood waters provide much needed water resources
Maintaining ecosystems
-
8/7/2019 GEOLOGY==tisis tisisan
30/31
30
Flooding adds a lot of nutrients to lakes and rivers
Suitability of a floodplain for spawning (little predation and a lot of nutrients) rivers
Fish like the weather fish make use of floods to reach new habitats
Together with fish also birds profit from the boost in production caused byflooding.
Deadliest floods
The significance of Civil Engineering in Floods
Preventing and making solutions are our main work with flood. We cannot stop
this kind of calamities but we can provide prevention and solution to stop a severe
damage. Through the structures we can make, we can direct the flow of floods and also
we can make a more reliable and stronger structure that can withstand such calamities
through Flood Control and of course to plant trees that hold the water.
We already experienced so much with floods and we have already much so we
must always be aware of this calamity.
-
8/7/2019 GEOLOGY==tisis tisisan
31/31