unit 4 ch.11 water

8/2/2019 Unit 4 Ch.11 Water

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Unit 4 Water, Air and LandCh. 11 Water


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11.1 Water Resources

EQ: Describe the Earths waterresources.


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The Water Cycle

Earthaka The WaterPlanet in all forms: solid,liquid, and gas

Water cycle continualmovement of water betweenthe earth and theatmosphere

Renewable resourcerecycled through thebiosphere


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Parts of the Water Cycle

Evaporation liquidto gas, leaves behindsalts and otherimpurities movesfrom surface toatmosphere

Condensation watervapor in the air risesand cools and

changes to tiny liquiddroplets that formclouds

Precipitation waterfalls back to earths

surface


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Global Water Distribution

71 % of earth iscovered with water

97% of that water is saltwater in the ocean

3% is freshwater 77% of that is frozen in

the icecaps 22% is in the form of

groundwater

1% surface water (lakes,rivers)


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Surface Water

Fresh water on earths land

Lakes, rivers, streams, and

wetlands Most cities built around fresh

water supply on the surface

Provide drinking water,irrigation, food, power, andtransportation


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Surface water; river systems

Flowing network of riversand streams on land

Streams form fromsnowmelt, rainfall thatdrains downhill

Streams combine to form

larger streams making ariver system

Ie Mississippi and

Amazon


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Surface water;watersheds

Watershed area ofland that is drained

by a river Pollution anywhere

in the watershed

can pollute the river


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Groundwater

Makes up the majority offreshwater available for humanuse

Groundwater water beneath theearths surface in rock andsediment formations comes from rain that soaks into the

soil

Water table level undergroundwhere rocks and soil are saturatedwith water Can form a spring where water table

meets surface


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Groundwater; aquifers

Aquifer underground formation that containswater Consist of materials like rock, sand and gravel with a lot

of open space between pieces Underground caves and lakes formed when groundwater

dissolves rocks like limestone

Important water source for cities and agriculture

Porosity - % of small holes or spaces per volume ofrock

Permeability ability of rock or soil to allow waterto flow through it


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Groundwater; recharge zone

Recharge zonearea of earths surface thatallows water to percolate down into anaquifer

Pollution in a recharge zone can percolateinto the aquifer

Buildings and pavement can formimpermeable barriers blocking percolation

into recharge zone. Well a hole dug into the ground that drills

into the groundwater Well will dry up if water table drops below the well


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11.2 Water Use and Management

EQ: Describe ways that water is usedaround the world.


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Global Water Use

Residential use - mostly personalhygiene, home cleaning, some fordrinking and cooking 300L per day per person in US Use outside the home = of total use

Water Treatment removeselements which are poisonous tohumans (Hg, arsenic, lead) Potable safe to drink

Pathogens organisms that causeillness in water that is contaminatedby sewage or animal feces

See page 296-297 for treatmentmethods


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Global Water Use

Industrial use 19% ofwater use Manufacture goods, dispose of

waste, generate power Power plant cooling system

Agricultural use 67% ofworlds use 80% of waterused is lost to evaporation

Irrigation providing plantswith a water source other thanprecipitation
http://upload.wikimedia.org/wikipedia/commons/a/ae/LevelBasinFloodIrrigation.JPG


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Water Management Projects

History streams and rivers have beenaltered to make use of the water i.e.Romans built aquiducts

Goals of WM projects: Bring water to dry areas to make habitable

Create reservoirs for recreation, drinking andgenerating power


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Water Diversion Projects

Provides water for dryareas

River water is diverted

through canals tolocation

i.e. Colorado riverprovides water for 7

states usually runsdry before it everreaches Mexico or theGulf of Mexico


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Dams and Reservoirs

Dam structure built across a riverto restrict the flow of water Hydroelectric dam use flowing water

to generate electricity Dam problems floods land, destroysecosystems, displaces people, sedimentgets deposited at dam instead offlowing downstream, farm land belowdam is less productive, failure of dam

Reservoir artificial lake formedbehind a dam Provides recreation, flood control,

irrigation, drinking water


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WaterConservation

Helps to ensure water foreveryone at a reasonable price

Agriculture a lot of water lost

to evaporation Drip-irrigation systems

Industry recycling of coolingand wastewater

Economic incentives for businesses Home water saving toilets and

shower, water lawns at night,xeriscaping


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Solutions for the future Conservation of water not

always enough to preventwater shortages

Desalination removing salt

from salt water, veryexpensive

Transporting Water bringingin freshwater from otherlocations

US 50% freshwater is in Alaska considering towing bags ofwater from rivers down toCalifornia

Towing icebergs


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11.3 Water Pollution

EQ: Compare point source pollutionwith non-point source pollution.


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Water Pollution

The introduction of chemical, physical, orbiological agents into water that degrade the

quality and adversely effect the organismsthat depend on the water

2 main causes: industrialization and rapid

human population growth


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Water pollution sources

Point source pollution from a single source Can be identified and traced to a source

Clean-up still may be difficult

Non-point source pollution from manydifferent sources like runoff from a watershed Difficult to regulate and control

When small amounts of pollution accumulate, itturns into a major problem

96% of polluted bodies of water

Lawn chemical runoff, motor oil in storm drains


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Type of Pollutants

Runoff from agriculture largest source

Pesticides, fertilizers, plant and animal

wastes Sewage-treatment plants 2nd largest

Pollutants usually in form of pathogens,

nutrients, or sediments Can also be toxic chemicals


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Chemical Pollutants

Toxic chemicals elements andcompounds that are directly harmfulto living things

Inorganic chemicals no carbon

Acids, salts,

Heavy metals high mass number(mercury, lead)

plant nutrients phosphates and nitrates

Usually enters groundwater or surfacewater through seepage, runoff, and

discharge into bodies of water


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Harmful effects of heavymetals by products of industrial

processes Factories either discharge

directly into water or seal theheavy metals into drums anddump them into the ocean or

bury them Poisonous

Causes brain, liver and kidneydamage

Case: 1950s Mimamata, Japan mercury poisoning 8000people suffered paralysis orbrain damage, 200 people died


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Organic chemicals come fromliving things and can be made inlabs (gasoline, oil, plastics,solvents)

Discharged from factoriesaccumulate in runoff fromagriculture

Crude oil common pollutant

shipped by water ways and canenter surface water during spills atdrilling sites or from shipwreckedor damaged tankers Devastates an ecosystem when spilled

(Exxon Valdez)


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Wastewater

Wastewater water that contains wastefrom homes or industry

Wastewater treatment plantwastewater is filtered and treated tomake water clean enough to return to a

river or a lake


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Treating Wastewater

Water contains biodegradablematerial that can be broken down byliving organisms

Some toxic substances in wastewaterand storm run-off cannot be removedby standard treatment

Sewage sludge solid materials thatremains after treatment Hazardous waste sludge has dangerous

levels of toxins Burned and ash buried


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Wastewater Treatment Process Primary Treatment

Filtration water passes throughscreen to remove large objects

1st Settling Tank smaller

particles sink to bottom to formsludge

Secondary Treatment Aeration water mixed with

oxygen and bacteria

2nd settling tank removesbacteria and solid wastes

Chlorination chlorine added todisinfect water

Water released to lake or stream


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ArtificialEutrophication

Eutrophication abundance ofnutrients in lakes and ponds Natural process when organic

matter decays and decomposes Changes the types of organisms

that live in pond because the levelof oxygen decreases

Artificial eutrophication

caused by humans fromfertilizer runoff and detergents As the oxygen gets used up the

fish and other organisms suffocate


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Thermal Pollution

Rise in the temperature of body ofwater

Caused when power plants andfactories discharge their cooling water

Warmer water doesnt hold as much

oxygen


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Groundwater pollution Usually comes when polluted surface water percolates down

into the ground Pollutants include pesticides, herbicides, chemical fertilizers, and

petroleum products

Also leaking underground storage tanks Clean-up takes many years because it takes so long for

groundwater to recharge Also pollutants can cling to sand and soil particles in ground


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Ocean Pollution 85% comes from activity on

land

Some from dumping wastewaterand garbage overboard

Oil spills 37 million gallons peryear Accounts for 5% of pollution

Most oil enters ocean from runoff

200-300 million gallons from non-point sources from land


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Water Pollution and Ecosystems

Can cause immediate damage(like dumping of toxic chemicals)

Some pollutants accumulate over

time causing damage moreslowly

Biomagnification build up ofpollutants at higher levels of thefood chain


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Cleaning up water pollution

Clean Water Act 1972restore and maintain thechemical, physical, and biological integrity of thenations waters Goal - water clean enough for swimming and fishing by

1983

Goal not met 30% increase in fit waters

Many states have stricter water quality standards

Many heavy metals removed from water before discharge

Oil Pollution Act 1990 ships in US waters must havedouble hulls by 2015

See pg 313


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Make a Public ServiceAnnouncement Poster

Choose a topic Ways to conserve water

Point-source pollution

Non-point source pollution

Ocean Pollution

Describe it, where it comes from, why it isbad

How can we fix it, or decrease the problem

Make a catchy slogan

unit 4 ch.11 water

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