1 end of year review hydrology 8 th grade science curriculum

1

End of Year Review

Hydrology

8th Grade Science Curriculum

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Hydrologic CycleHydrosphere• The portion of the

Earth that contains water.

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Essential Question #51

• How is water distributed on earth?

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Distribution of Fresh Water on Earth

• Fresh water

• Groundwater

• Glaciers• Icecaps

• Icebergs

• Water without salt• Water that infiltrates the

soil and rock to get underground

• Percolates through permeable rock

• Stops at impermeable rock

• River of ice on land• Areas of permanent snow

and ice at the poles• Large floating masses of

ice detached from a glacier or icecap

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Credit: Earth Forum, Houston Museum of Natural Science For more info:

Earth Forum, Houston Museum of Natural Science

6www.chemtronicsindia.com/water-treatment.htm

http://www.chemtronicsindia.com/water-treatment.htm

http://www.chemtronicsindia.com/water-treatment.htm

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Where is most freshwater located on Earth?

A.Polar ice capsB.Groundwater

C.LakesD.Rivers

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Where is most freshwater located on Earth?

A.Polar ice capsB.Groundwater

C.LakesD.Rivers

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• How is water distributed on earth?

•Class Discussion

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Hydrologic Cycle• How does

water get into the atmosphere?

• Water evaporates from the oceans, rivers, lakes, and ponds.

• Water is transpired from the leaves of plants (transpiration)

• Water is exhaled by animals

www.hometrainingtools.com

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Hydrologic Cycle• How does

water get back onto land?

• Water vapor condenses in the cold upper atmosphere as ice crystals or liquid.

• When flakes or drops are large enough, they fall back down as precipitation: snow, rain, sleet, hail

www.hometrainingtools.com

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• What is a river basin?

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Hydrologic Cycle• What happens

to water that falls on the land?

Surface Water• Glaciers and ice

caps trap some of the water

• Runoff flows into lakes and ponds then on to the oceans

• Some water is taken in by living things

www.ncwildlife.org/.../images/img10b5a_02.gif

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Hydrologic CycleWhat happens

to water that falls on the land?• Reservoir is a lake that stores water for human use.

• Wetland is a land area that is covered with a shallow layer of water during some or all of the year.

• Drought occurs when there is a long period of scarce rainfall.

Surface Water (continued)

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Hydrologic CycleWhat happens

to water that falls on the land?

• Some percolates down into the soil and rock layers

• Aquifer: is a layer of rock that is porous enough to hold large amounts of water

• Artesian well: is water that is forced out of an aquifer by gravity.

• Water table: top of the groundwater in an aquifer

Groundwater

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North Carolina River Basins• What is a

river basin?

• Which river basin do you live in?

• The region of land drained by a river and its tributaries.

• Also known as a watershed

• Neuse or Cape Fear

www.fws.gov/nc-es/fish/CFSRockyRiver1.jpg

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• What is a river basin?•The region of land drained by a river and its tributaries. Also known as a watershed

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• Which river basin do you live in?

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North Carolina River Basins

www.harnett.org/search-site-map.asp?Keyword=n...

http://www.harnett.org/search-site-map.asp?Keyword=nc&pgno=14

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Essential Question #53• Which river basin do you live

in?• Fuquay-Varina is on the border of the Neuse River

Basin to the north and east and the Cape Fear River Basin to the south and

west.

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Which describes the hydrosphere?

A.Most of it contains salt.B.It is made of only

freshwater.C.All of it is located above

ground.D.It is formed by a climate

change.

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Which describes the hydrosphere?

A.Most of it contains salt.B.It is made of only

freshwater.C.All of it is located above

ground.D.It is formed by a climate

change.

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• Where does drinking water come from?

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Sources of Drinking Water OR

Water for Human Consumption• Water

Treatment Plants

• Makes water safe for human consumption by taking out impurities and adding chemicals to kill bacteria

• The source of water can be a lake, river, or reservoir

www.cacoastkeeper.org/groundwater.php

http://www.cacoastkeeper.org/groundwater.php

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• How do we treat our water so we can use it in our homes?

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Water Treatment Plants

www.sandiego.gov

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• How do we treat our water so we can use it in our homes?• Can you remember the

process without going back to the last slide?

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Sources of Drinking Water OR

Water for Human Consumption

•Wells

• Brings groundwater up after it has been naturally filtered by percolating down through the layers of soil and rock

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• Where does drinking water come from?

•Water treatment plants and wells

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Measuring RainfallA rain gauge is used to measure

rainfall

www.enterthejournals.com

www.grasstec.ie

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Which tool is used to determine precipitation

amounts?

A.Balance scaleB.HygrometerC.Rain gauge

D.Thermometer

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Which tool is used to determine precipitation

amounts?

A.Balance scaleB.HygrometerC.Rain gauge

D.Thermometer

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OceansTerms to Understand

• Intertidal Zone: land covered by tides part of the day

• Neritic Zone: ocean over the continental shelf• Oceanic Zone: deep, open ocean• Continental Shelf: from the edge of the

continent to where the continental slope drops sharply

• Continental Slope: steep incline between the continental shelf and the abyssal plain

• Trench: deepest part of the ocean. Marianas Trench-5 miles deep

• Seamount: underwater volcano• Abyssal Plane: deep, flat portion of the ocean

floor• Mid-Ocean Ridge: chain of undersea volcanoes

where the sea floor spreads• Photic Zone: top layer of ocean that sunlight

reaches• Aphotic Zone: lower layer of ocean that sunlight

does not reach

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OceansIntertidal Zone

OR

Or Neritic Zone

Or Photic Zone

Aphotic ZoneOR

________________Oceanic Zone_________________

www.fao.org

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Characteristics of the Zones• Photic

Zone

• Aphotic Zone

• Gets sunlight so organisms can photosynthesize

• Marine producers live here• Some algae have holdfasts

(root-like structures) • No light so no photosynthesis• Extreme cold and pressure• Some organisms are

Bioluminescent (glow because of cellular chemical reactions

• Most eat organisms that sink• Organisms at hydrothermal vents

are chemotropic (use chemicals for food)

www.kidsbiology.com

www.alga-net.com

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Characteristics of the Zones• Intertidal Zone

•Neritic Zone

•Open Ocean Zone

• Dry land during low tide but underwater at high tide

• Organism tolerate being out of the water for part of the day

• Over the continental shelf• Organisms adapted to warmer,

sunlit, low pressure environment

• Environment over abyssal plain• Organisms adapted to colder, dark,

high pressure environment

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Ocean Floor• Mid-

ocean Ridge

• Volcanic area where new ocean floor is being made

seafloor spreading. Wikimedia Commons (Public Domain)

HydrothermalVent / /

http://commons.wikimedia.org/wiki/Image:Ridge_render.jpg

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Salinity• Is the amount of dissolved solids in the

oceans. Mostly salt (NaCl)• High salinity increases density of water• Caused by rain picking up salts on land,

then carrying them to the oceans

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After fishing in the ocean, a student left his fishing gear in the sun to dry. Later, he noticed that small white

crystals had formed on the rod, reel, and fishing line. Which of these is the best explanation of what occurred?

A. The water evaporated from the fishing gear, and sand was attracted

to it.B. The fish that were caught left scales

on the fishing gear.C. The salt in the ocean water reacted

with the fishing gear and caused it to rust.

D. The water evaporated from the fishing gear, and salt from the ocean

was left behind.

41

After fishing in the ocean, a student left his fishing gear in the sun to dry. Later, he noticed that small white

crystals had formed on the rod, reel, and fishing line. Which of these is the best explanation of what occurred?

A. The water evaporated from the fishing gear, and sand was attracted

to it.B. The fish that were caught left scales

on the fishing gear.C. The salt in the ocean water reacted

with the fishing gear and caused it to rust.

D. The water evaporated from the fishing gear, and salt from the ocean

was left behind.

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• What is an upwelling?

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Temperature of the Oceans• Water is most dense at 4C• Warm water rises and cold water sinks• Lower layers of the oceans are cold• Upper layers of the oceans are warm• Nutrients sink when organisms die and

decompose• An upwelling occurs when winds cause

cold, nutrient rich water to move up• Plankton thrive in these waters becoming

food for larger organisms• El Niño is a wind in the Pacific Ocean that

can cause very large upwellings making the Pacific more productive.

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Plankton grow and multiply in the nutrient rich waters

www.galapagosonline.com/.../Upwelling.jpg

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Essential Question #56• What is an upwelling?

• Winds cause water to be blown away from shore. Deep, nutrient rich water comes up to replace it. Plankton thrive on the nutrients making for

organisms higher in the food chain.

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Which condition in the ocean is most responsible for an increase in the fish

population near the surface?

A.BuoyancyB.DensityC.Salinity

D.Upwelling

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Which condition in the ocean is most responsible for an increase in the fish

population near the surface?

A.BuoyancyB.DensityC.Salinity

D.Upwelling

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Ocean DepthsOrganisms that live in the deep oceans

have to adapt to several extreme conditions

1. High pressure: organisms that live deep are under pressures that would crush a submarine

2. Darkness: no light gets to these depths so some organisms have bioluminescence or the ability to produce their own light

3. Cold temperatures: at these depths, ocean water is around 3C which is near freezing

oceanexplorer.noaa.gov/.../media/fig3b_600.jpg

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• What types of organisms are the most abundant in marine

ecosystems?

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Life in the Oceans• Necton

• Benthos

• Plankton

• Phytoplankton

• Zooplankton

• Free-swimming consumers whose movements are independent of currents

• Examples: fish, whales, turtles

• Life on the entire ocean floor; mostly small invertebrates that are consumers (heterotrophs)

• Tiny organisms that make up most of the life in the oceans

• Small plant-like producers (most abundant) that photosynthesize food (autotrophs)

• Example: Diatoms are one-celled algae w/ glass plates

• Small animal-like consumers (heterotrophs)

• Around thermal vents, some are chemotrophs (another type of autotroph) or live on chemosynthesis

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Essential Question #57• What types of organisms are

the most abundant in marine ecosystems?

• Zooplankton and Phytoplankton

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• Why are estuaries important?

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Marine EcosystemsEstuaries

• Areas where rivers flow into the oceans mixing fresh water with salty ocean water

• Nurseries for young marine organisms to mature

• Are wetlands that an absorb pollution

• Many have been filled to make room for buildings

• This resulted in fish numbers dropping

www.dep.state.pa.us/.../spatterdockagain.JPG

io.uwinnipeg.ca/.../1116/50-21b-Estuary.jpg

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• Why are estuaries important?

• Nurseries for young marine organisms to mature

• Are wetlands that an absorb pollution

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• Why should we protect our marine resources?

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Sustainability• Pollutants can throw delicate balances

off and cause many problems

• Too much pollution will lead to our losing the oceans as natural resources

2.bp.blogspot.com/.../s400/

thumbnail.jpg www.gaszappers.com

dadecosurf.com

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• Why should we protect our marine resources?

• Pollutants can throw delicate balances off and cause many

problems

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• What kinds of technologies are used to monitor the

hydrosphere?

59


• What kinds of information have we learned from deep ocean

technology?

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Technology• ROV

(Remotely Operated Vehicle)

• Scuba (Self Contained Underwater Breathing Apparatus)

• Unmanned submersible tethered to a mother ship and operated by pilots using a joy stick

• Device that allows divers to breathe underwater for long periods of time

www.defenseindustrydaily.com

www.boracay-budgettravel-tips.com

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Technology• SONAR – SOund

NAvigation Ranging

• Used to measure ocean depth by sending sound to bounce off the ocean floor

community2.myfoxdfw.com

www.wisconsinhistory.org

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Technology• Submersible • A small submarine

used to explore the ocean depths; equipped with windows, lights, mechanical arms, cameras, and other scientific instruments capable of seeing and recording data

private-submarines.com

oceanexplorer.noaa.gov

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• What kinds of information have we learned from deep ocean

technology?• Shape of the ocean floor

• Types of organisms• Can you think of others?

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Technology• Satellites study the ocean.

www.eohandbook.com

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• What kinds of technologies are used to monitor the

hydrosphere?• How many can you

remember?

66


• what does turbidity tell you about the health of a water

system?

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Water QualityTurbidity• Cloudiness of water

• Measured using a secchi disk

• Measured by the length of the string when you’ve lost sight of the disk

• Some cloudiness is good but too much kills sensitive organisms

pond.dnr.cornell.edu

www.co.carver.mn.us

ian.umces.edu

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• what does turbidity tell you about the health of a water system?

• Too clear and water may not have needed nutrients.

• Too cloudy and organisms can’t survive

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• How do gases behave in the marine environment?

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Dissolved Gases in Water Environments

• Cold water dissolves oxygen (O2) better than warm water so some fish do better in cold water than warm. Heat can be a pollutant because it can remove oxygen.

• Carbon dioxide (CO2) dissolves in water so water plants and algae can use it for photosynthesis

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• How do gases behave in the marine environment?• Class Discussion

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Essential Questions #64-65

• How do Temperature changes affect the health of a water system?

• How do changes in the amount of dissolved oxygen affect the health of a

water system?

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Temperature• Changes in temperature can cause

dissolved gases, such as O2, to fluctuate. • Organisms can’t adjust to changes in

temperature and dissolved gas levels and die.

• Changes in populations disrupt the ecology of a body of water.

clean-water.uwex.edu/pubs/clipart/runoff.25.htm

http://clean-water.uwex.edu/pubs/clipart/runoff.25.htm

http://clean-water.uwex.edu/pubs/clipart/runoff.25.htm

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• How do Temperature changes affect the health of a water system?

• How do changes in the amount of dissolved oxygen affect the health of a

water system?• Class discussion

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• How do changes in pH affect the health of a water system?

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pH of WaterWater should be neutral (7). If it isn’t,

organisms can’t adjust and die out.

www.livinglandscapes.bc.ca

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• How do changes in pH affect the health of a water system?

• Healthy water should have a pH of around 7. Too acid or basic can cause damage to

organisms.

78


• How do nitrates affect the health of a water system?

• What are some possible effects of excess nutrients in NC waters?

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Nitrates• Nitrates usually get to a body of water

from farm fertilizer runoff. It acts as a fertilizer for algae that can grow too much and choke a pond, lake, or stream. This is eutrophication

www.samford.edu www.time.com

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• How do nitrates affect the health of a water system?

• What are some possible effects of excess nutrients in NC waters

(eutrophication)?• Class discussion

81


• what are bioindicators and how can they help you predict the

health of a water system?

82

Bioindicators

Some organisms are very sensitive to pollution. If a body of water has these organisms, it means the water is healthy. If they are not in the water, something is upsetting the balance of the system.

www.boquetriver.org

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• what are bioindicators and how can they help you predict the health of a water

system?

Examples include: • Mussels disappear if the water is too

turbid.• Mayflies disappear if the water is too

acidic.

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Ecology• Producers

• Consumers

• Autotrophs: make their own food

• Photosynthesis: make sugars using light as energy

• Chemosynthesis: make sugars using substances around them

• Heterotrophs: get their food from other organisms

• Eat food made by producers

• Eat other organisms• Eat the dead bodies of

other organisms

students.umf.maine.edu

www.abeautyjournal.com

www.ehow.com/how_2101230_go-cow-tipping.html

whatthecrap.wordpress.com

soe.ucdavis.edu

http://www.ehow.com/how_2101230_go-cow-tipping.html



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Ecology

• The living organisms of the environment

• The non-living factors of the environment

Biotic Factors Abiotic Factors

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• How are aquatic and terrestrial food webs

connected?

87

Ecology• Ecosystem

• Habitat

• Food Web

• A community of different by interdependent species and their non-living environment

• The immediate space where an organism lives

• A community’s interaction of all producers and consumers

library.thinkquest.org

Terrestrial Aquatic

cmore.soest.hawaii.edu/.../marine_web_full.jpg

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Terrestrial and

aquatic food websoverlap.

These food webs

depend on each

other

mac122.icu.ac.jp

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Essential Question #70• How are aquatic and

terrestrial food webs connected?

• Both overlap and depend on each other.

90

Which pair of organisms represents a connection between an aquatic and terrestrial food webs?

A.Whales and planktonB.Seagulls and oysters

C.Spiders and mosquitoesD.Humans and coral

91

Which pair of organisms represents a connection between an aquatic and terrestrial food webs?

A.Whales and planktonB.Seagulls and oysters

C.Spiders and mosquitoesD.Humans and corn

92

Ecology

Food Chain• A hierarchy of food

relationships from the simplest to the most complex

93


• What are some examples of point and non-point sources of

water pollution in NC?

94

Water Quality• Point

Source Pollution

• Non-point Source Pollution

• A single pollution source can be identified

• A single source cannot be identified because the pollution may have many sources

cache.daylife.com/.../01yv6sKfFC7qx/610x.jpg

www.schools.nsw.edu.au

localhistory.wordpress.com/

http://localhistory.wordpress.com/

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• What are some examples of point and non-point sources of

water pollution in NC?• Class discussion

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• What are the economic tradeoffs when dealing with water quality?

• What local water issues are we dealing with now or have dealt with in the past?

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Protecting Our Water• Locally, wells have been found to

contain chemicals used years ago on farms.

• We have to make decisions between the use of polluting chemicals or living without them.

• We have to improve water supplies to protect all of us from the possible contamination of many pollutants

• How can we keep our water safe?

98


• What are the economic tradeoffs when dealing with water quality?

• What local water issues are we dealing with now or have dealt with in the past?

• Class discussion

99

If a farmer decides to have a pesticide-free farm, which is most likely the

result of this choice?

A. The farmer’s crops will yield more than if pesticides had been applied.

B. The farmer’s crops will yield the same amount whether or not pesticides

have been applied.C. Insects may eat a larger percentage

of the farmer’s crops, causing a lower harvest than if pesticides had been

applied.D. Insects may eat a lower percentage

of the farmer’s crops, causing a higher harvest than if pesticides had

been applied.

100

If a farmer decides to have a pesticide-free farm, which is most likely the

result of this choice?

A. The farmer’s crops will yield more than if pesticides had been applied.

B. The farmer’s crops will yield the same amount whether or not pesticides

have been applied.C. Insects may eat a larger percentage

of the farmer’s crops, causing a lower harvest than if pesticides had been

applied.D. Insects may eat a lower percentage

of the farmer’s crops, causing a higher harvest than if pesticides had

been applied.

101


• Why do we call water the universal solvent?

• How can you explain polarity in terms of water molecules?

102

Properties of Water

Structure of water

• Water is neutral• Oxygen (O) atom is

larger than the H atoms so electrons spend more of their time nearer the oxygen

• This gives water a slight overall charge

• That charge is called polaritywww.amnh.org/learn/courses/images/W3E1_1.jpg

103


• How can you explain polarity in terms of water molecules?

• The oxygen atom in water has a slight negative charge and the hydrogen atoms have a slight

positive charge. Therefore, the molecule is polar.

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Properties of Water

Water is called the universal solvent.

WHY?

• Water is polar.• Water molecules

attract molecules of other polar substances.

• So all polar molecules that are added to water get pulled apart (dissolved) by the water molecules

105

Properties of Water

www.biology.arizona.edu/.../chemistry/page3.html

http://www.biology.arizona.edu/.../chemistry/page3.html

106


• Why do we call water the universal solvent?

• Polarity of water pulls other polar molecules

apart.

107

Properties of WaterHydrogen Bond

Water forms bonds between water molecules. What does this mean?The polarity of water causes the molecules to be attracted to each other.

sciencehelpdesk.com

108

Properties of waterIn water vapor

(gas), hydrogen bonds don’t form.

In water (liquid), hydrogen bonds don’t last long except along the surface.

In ice (solid), hydrogen bonds form and molecules stay in place.

www.biology.arizona.edu/.../chemistry/page3.html

http://www.biology.arizona.edu/.../chemistry/page3.html

109


• How can you explain cohesion and adhesion in terms of

water molecules?

110

Properties of Water

Density of ice is less than that of liquid water.

The bonds keep the molecules at a distance increasing volume.

This is why water expands when freezing

This is why ice floats.

sciencehelpdesk.com

111


• How does water hold heat? (Specific heat)

112

Properties of WaterThe natural attraction of a water

molecule to other water molecules is called cohesion

plantphys.info

113

Specific Heat – the ability to absorb heat.

• Due to strong hydrogen bonds, water molecules attract each other.

• Energy must be added to break these bonds.

• Water can absorb high amounts of energy because of these bonds.

• This means water has a high specific heat.

114


• How does water hold heat? (Specific heat)

• Hydrogen bonds keep water molecules tightly packed.

• Water holds high amounts of heat energy due to these bonds.

115

Properties of WaterAdhesion is the natural attraction of a

water molecule to other polar objects. This can be seen as water droplets form on the spider web.

upload.wikimedia.org

http://upload.wikimedia.org/wikipedia/commons/9/96/Water_drops_on_spider_web.jpg

116

Properties of Water

1. Gravity is ALWAYS pulling on objects with mass

2. Yet water can move up a paper towel with relative ease. Why?

3. Because the positive and negative charges in the paper attract the polar water molecules (adhesion)

4. This property of adhesion is called capillary action

Water Molecules bonded to paper towel

www.davidlnelson.md

117


• How can you explain cohesion and adhesion in terms of water

molecules?• Class discussion

118

bloody2.com/images/capillary%203.jpg

www.sciencebuddies.org/.../PlantBio_img014.jpg

Capillary Action

www.uni.edu/~iowawet/animations/capilary.gif

119

Properties of WaterInside a body of water, polar water molecules attract each

other in a random fashion.At the surface, water is not attracted to the air.A layer of molecules at the surface creates surface tension. At the surface, the water behaves like a flexible sheet allowing

denser objects to “sit” on the surface.

www2.uni-siegen.de/

mrgontasz.com

120


• Why do objects sink or float in water (density and

buoyancy)?

121

Properties of WaterBuoyancy • the ability of a fluid to exert an upward

force on an object that is immersed in a fluid

• The buoyancy force is equal to the mass of the water displaced by a floating object

www.pbs.org/wgbh/nova/lasalle/buoybasics.html

http://www.pbs.org/wgbh/nova/lasalle/buoybasics.html

122misclab.umeoce.maine.edu/.../buoyancy.gif

123

Essential Questions #78

• Why do objects sink or float in water (density and buoyancy)?

• Water has an upward force on objects.

1 end of year review hydrology 8 th grade science curriculum

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