chapter 11-water water resources. water water planet- earth has an abundance of water in all forms:...

Chapter 11-Water

Water Resources

Water

“Water Planet”- Earth has an abundance of water in all forms: solid, liquid, and gas.

Renewable resource because it is circulated in the water cycle.

Humans can only survive a few days without water.

Two kinds of water on Earth:Fresh water- Can drink because it contains little salt.Salt water- Ocean water with a high concentration of

salt.

The Water Cycle

Global Water Distribution

97% salt water3% fresh water

77% of fresh water frozen in icecaps and glaciers

22% ground water1 % other

Global Water Distribution

Surface water- Fresh water on Earth’s land surface.Lakes, rivers, streams, and wetlandsRiver systems- Flowing network of water

comprised of streams and rivers.Amazon river system- largest in the worldWatershed- Area of land that is drained by a

river.

Watersheds of the World

Global water Distribution

Ground Water- Water stored beneath the Earth’s surface in sediment and rock formations.Water table- Level where the rocks and soil are

saturated with waterAquifer- Underground formation that contains waterPorosity- Amount of space between the particles that

make up a rock.Permeability- The ability of rock or soil to allow

water to flow through it. Permeable- Allows the flow of water.Impermeable- Does not allow the flow of water.

Ground Water- Cont’d.

The Recharge Zone- The area of the Earth’s surface where water percolates down into an aquifer.

Wells- A hole that is dug or drilled to reach groundwater

Chapter 11-Water

Water Use and Management

Global Water Use

Most freshwater used globally to water crops.

19% of global water use for industry

Only 8% of global water used for washing and drinking.

Residential Water Use

Striking differences among countries around the world

U.S. residents use on average 300 L of water per day

Indian residents use on average 41 L of water per day

Water Treatment

Potable- Safe to drink.Treatment must remove elements:

mercury, arsenic, and leadFound in polluted and ground waterPathogens- Organisms that cause illness

or diseaseSee Figure 6, Pages 276-277

Water Treatment

Water Use

Industrial- 19% of water use in worldManufacture goodsDispose of wasteGenerate powerMost used to cool

power plants

Agricultural- 67% of water use in world80% of water used in

agriculture evaporates

Irrigation- Method of providing plants with water from sources other than direct precipitation.

Water Use

Water Management Projects

Aqueducts- Huge canals that brought water from the mountains to dry areas.

Dams and water diversion canals used today.Water management projects today:

Bring in water to make a dry area habitableCreate a reservoir for recreation or drinking waterGenerate electric power

Water Management Projects

Water Diversion Projects- To supply dry regions with water, all or part of a river can be diverted into canals that carry water across great distances.

Water Management Projects

Dam- Structure built across a river to control the river’s flow.Can be used to generate electricity.Problems: flooding, ecosystem destruction,

and dam failure Fertile sediment builds up behind dams

Reservoir- Artificial lake formed behind a dam.

Water Conservation

Water becomes more expensive as it depletes.

Agriculture: Most water loss from evaporation, seepage, and runoffDrip Irrigation System- Small amounts of

water delivered directly to roots using perforated tubing.

Water Conservation

Home:Water-saving technology such as low-flow toilets

and shower headsWater lawns at nightXeriscaping- Designing landscapes that require

minimal water use.

Industry: Recycling of cooling water and wastewaterCity wide/company wide water saving plans

Solutions for the Future

Desalination- Process of removing salt from salt water Heats water and collects evaporationMiddle East/Kuwait has desalination plants

Transporting Water Transporting in bags and/or large plastic containers

from abundant supplies to low supplied regionsTowing icebergs??

Chapter 11-Water

Water Pollution

Water Pollution

The introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water.

Types of Water Pollution

Nonpoint-source Pollution Pollution that comes from

many different sourecs Difficult to identify and

trace/regulate and control 96% of polluted water in

U.S Point-source Pollution

Pollution discharged from a single source

Can be identified and traced

.

Pollutant Types and Sources

Wastewater

Water that contains waste from homes or industry.Treating

Most contaminates are biodegradableSome toxic substances cannot be removed by

standard treatment

Wastewater

Sewage sludgeSolid material that remains after treatmentSometimes hazardous wasteOften incinerated and ash buriedCan be used as fertilizer or bricks

Water Pollution

EutrophicationContaining an

abundance of nutrients

Leads to swamp or marsh

Artificial Eutrophication- Sewage and fertilizer runoff enhancesEx: Algal blooms

Thermal Pollution- Increased temperature of water sources caused by factories and industries cooling systemsDecreases oxygen

levelsKills organisms

Water Pollution

Groundwater pollution- Polluted surface water percolates down to groundwaterLeaking underground

storage tanks are large problem

Remains for 100s to 1000s of years

Ocean pollutionCoastal ecosystems

most affectedLegal to dump in

some parts of oceanOil spills

5% of ocean pollutionNonpoint-source

pollution from land 10 times more than tanker spills

Oil Spills

Water Pollution

Biomagnification- Accumulation of pollutants at successive levels of the food chain.Many pesticidesExample: DDT and

the Bald Eagle

Clean Water Act of 1972- To restore and maintain the chemical, physical, and biological integrity of the nation’s waters. Goal to make fishing and

swimming safe by 1983.Not achieved30% increaseOpened door for more

legislation

Biomagnification

Water Quality Federal Laws