Water Resources

WATER RESOURCES

The Walker School

Environmental Science

Importance of Water

Keeps Us Alive

Moderates Climate

Sculpts the Land

Dilutes Solid Wastes

Removes Pollutants

Distribution of Earth’s Water

1.36 billion km3 of water on Earth

Pacific Institute Monitors World’s Water

http://www.worldwater.org/data.html

USGS Water Monitoring http://water.usgs.gov/

Real Time Water Datahttp://waterdata.usgs.gov/usa/nwis/rt

Samples Hydrograph

Fig. 15-19, p. 475

Properties of Water

Strong Forces of Attraction

Exists as Liquid Over Wide Temperature Range

Changes Temperature Slowly

Evaporation Takes Large Amounts of Energy

Can Dissolve a Variety of Compounds

Filters UV Radiation

Expands When Frozen

Hydrologic Cycle

Fig. 15-3, p. 460

Water Characteristics•Flow•Viscosity•Infiltration Capacity•Gradiant

WHAT IS SURFACE WATER?

Surface Water is RunOff

Streams

Lakes

Wetlands

Reservoirs

World Drainage Basin

An area which a stream or river and its tributaries carry all surface runoff.

Ocean Drainage Basins

The Atlantic Ocean drains approximately 47% of all land

in the world.

The Pacific Ocean drains just over 13% of the land in the

world.

The Arctic Ocean basin drains most of Western and

Northern Canada east of the Continental Divide.

The Indian Ocean drains around 13% of the Earth's land.

The Southern Ocean drains Antarctica.

Watershed

A watershed or drainage basin is a region from which water drains into a stream, lake, reservoir, wetland or other body of water

River Basins

The three largest river basins (by area), in order of largest to smallest, include the Amazon basin, the Congo basin, and the Mississippi basin.

The three rivers that drain the most water, from most to least, are the Amazon, Congo , and Ganges Rivers.

Mississippian Drainage Basin

Fig. 15-22b, p. 480

Primary River

Secondary Tributary

Confluence Point

Endorheic Drainage Basins

Inland basins that do not drain into an ocean;

18% of all land drains to endorheic lakes or seas.

The largest of these consists of much of the interior of Asia, and drains into the Caspian Sea and the Aral Sea.

Evaporation is the primary means of water loss

Water is typically more saline than the oceans.

Aral Sea Drainage Basin

Types of Drainage Systems

Fig. 15-23, p. 481

1. DendriticDrainage2. Rectangular Drainage3. Trellis Drainage4. Radial Drainage5. Deranged Drainage

Drainage Patterns and Geology

Dentritic Drainage

Rectangular Drainage

Trellis Drainage

Radial Drainage

Deranged Drainage

Erosion Deposits

Regional Joint Systems

Folded Sedimentary Rock

Volcanoes

Swamps and Lakes

Tennessee Drainage Basin

Watershed is part of Alabama, Georgia, Mississippi, North Carolina, and Tennessee

The Tennessee River is formed at the confluence of the Holston and French Broad Rivers Georgia

The river has been dammed numerous times, primarily by Tennessee Valley Authority (TVA) projects. Tennessee

Check Google Earth and Identify the Type of Drainage Basin

Stream Piracy

Occurs when headward erosion breaches a divide

and diverts some or all of the drainage of another

stream system.

The Hadhramawt Plateau of South Yemen exhibits a complex dendritic drainage pattern and excellent examples of "stream piracy”.

A

BA. - Wadi Hadhramawt opens into the sand-filled RamlatSabatayn in the southwest corner of the Rub-al-Khali (The Empty Quarter), B - yet drainage is toward the sea.

• Deliver nutrients to the sea

sustain coastal fisheries

• Deposit silt that maintains deltas

• Purify water

• Renew and nourish wetlands

• Provide habitats for aquatic life

• Conserve species diversity

WHAT IS GROUND

WATER?

Importance of Ground Water

Aesthetic Value: beautiful caves, caverns and

deposits

Economic Value: source of fresh water for

agriculture, industry and domestics use.

Bequeath Value: need to conserve water for future

generations.

Ecological Services: supports ecosystems, filters

chemical pollutants, filters microscopic organisms

Groundwater

Water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formations.

Includes soil moisture, permafrost (frozen soil), immobile water in very low permeability bedrock, and deep geothermal or oil formation water.

The study of the distribution and movement of groundwater is hydrogeology.

Aquifers

A unit of rock or an unconsolidated deposit is

called an aquifer when it can yield a usable

quantity of water.

Ogallala Aquifer is one of the largest in the world.

Confined vs. Unconfined

The upper level of this saturated layer of an unconfined aquifer is called the water table or phreatic surface.

Water Table

The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table.

Zones of the Water Table

Groundwater Movement

Gravity

HOW MUCH OF THE WORLD’S

RELIABLE WATER SUPPLY ARE WE

WITHDRAWING?

Global Water Withdrawal

78% of Global Water

Supply Withdrawn Each Year

18% is for Irrigation;

40% is for World Food

Production

20% for Industry

National Water Footprints

United States China

Industry 11% Public 10%

Power

cooling

38%

Agriculture

41% Agriculture 87%

Public 6% Industry 7%

U.S. Water Withdrawal & Use

Global Water Withdrawal

Global withdrawal has increased 9x in the

last 100 years

Humans now withdraw about 34% the

worlds reliable runoff

Rates are predicted to double in the next

20 years and exceed demand in a number

of regions

Projected World Water Availability

5,500

5,000

4,500

4,000

3,500

3,000

2,500

2,000

1,500

1,000

500

1900 1920 1940 1960 1980 2000

Wate

r u

se (

cu

bic

kilo

mete

rs p

er

year)

Total use

Agricultural use

Industrial use

Domestic use

Year

Water Usage by Production

Average annual precipitation (centimeters)

Less than 41

41-81

81-22

More than 122

Acute shortage

Shortage

Adequate supply

Metropolitan regions with population

greater than 1 million

Serious Water Problems 1. Flooding2. Urban Shortages3. Pollution

Groundwater Withdrawl

Agriculture

Industry

Wells and Cones of Depression

A cone of depression forms when water is withdrawn from a well. The cone will grow in depth and circumference, lowering the water table and making nearby shallow wells go dry.

Saltwater Intrusion

Subsidence of Cities

Contamination of Groundwater

WHAT CAUSES FRESHWATER

SHORTAGES?

Causes of Fresh Water Shortages

Dry Climate

Drought

Desiccation

Water Stress

High None

NorthAmerica

SouthAmerica

Stress

Africa

Europe

Asia

Australia

Stress on World’s Major River

Basins

World Water Hotspotshttp://news.bbc.co.uk/1/shared/spl/hi/world/03/world_forum/water/html/default.st

m

World Water Facts

http://news.bbc.co.uk/2/low/science/nature/4787758.stm

One billion people without access to clean drinking water

2.6 billion without adequate sanitation

Rapid urbanization increasing pressure on water resources

30-40% of water 'lost' through illegal tapping and leaks

Populations w/o Access to Safe

Drinking Water

Populations w/o Access to Sanitation Services

Movie: Running Dry

What We Can Do

Build Dams and Reservoirs to Store Runoff

Bring in Surface Water from Other Areas

Withdraw Ground Water

Convert Salt Water to Fresh Water

Waste Less Water

Import Food to Reduce Water Use

Problems With Privatized Water

They have more incentive to

sell as much water as they

can rather than to conserve it.

The poor will continue to be

left out because of a lack of

money to pay water bills.

WHAT ARE THE ADVANTAGES AND

DISADVANTAGES OF LARGE DAMS AND

RESERVOIRS?

Trade-Offs of Dams

Dams Around the World

800,000 dams, total estimate

45,000 large dams

22,000 large dams on the world’s 227 largest

rivers

DamAqueductor canalUpper Basin

Lower Basin

IDAHOWYOMING

UTAH

Salt Lake City

Las Vegas

CALIFORNIABoulder City

Los Angeles

Palm Springs

San DiegoMexicali

Yuma

Phoenix

Tucson

LOWER

BASIN

ARIZONA

GrandCanyon

UPPER

BASIN

Grand Junction

Denver

COLORADO

NEW MEXICO

Albuquerque

MEXICO

Lake

PowellGlenCanyonDam

All-AmericanCanal

Gulf ofCalifornia

0

0

100 mi.

150 km

Drainage Basin of Colorado River

Problems w/ River Water Usage from The Colorado

River

Supplies water to some of the driest land in the S.

West.

Legal pacts have legislated more water usage to

U.S. and Mexico than the river can supply

Low water threatens spawning fish

80% is used to irrigate crops and raise cattle

Three Gorges Dam

Location of the Dam

RUSSIA

MONGOLIA

CHINA

NEPAL BHUTAN

INDIABANGLADESH

BURMA LAOS

VIETNAM PACIFIC

OCEAN

Beijing

CHINA

Jailing

River

Chongquing

YichangWunan

Yangtze

River

Shanghai

YELLOW

SEA

EAST

CHINA

SEA

ThreeGorges

Dam

Reservoir

WHAT ARE THE CAUSES AND

EFFECTS OF FLOODING?

Humans Increase Flood Damage

Removing Water Absorbing Vegetation

Draining Wetlands that Absorb Floodwaters and

Reduce

Living in Flood Plains

Oxygenreleased byvegetation

Diverseecological

habitat

Evapotranspiration

Trees reduce soilerosion from heavyrain and wind

Agriculturalland

Steadyriver flow

Leaf litterimprovessoil fertility

Tree rootsstabilize soil andaid water flow Vegetation releases

water slowly andreduces flooding

Forested Hillside

Protect Forests

After Deforestation

Tree plantation

Evapotranspiration decreases

Ranchingacceleratessoil erosion bywater and wind

Winds removefragile topsoil

Gullies andlandslides

Heavy rain leachesnutrients from soiland erodes topsoil Rapid runoff

causes flooding

Roadsdestabilizehillsides

Agriculture landis flooded andsilted up

Silt from erosion blocksrivers and reservoirs andcauses flooding downstream

FloodplainLevee Flood

wall

Dam

Reservoir

Humans Modify Flood Plains

Flood Plain Services

Provide Natural Flood and Erosion control

Maintain High Water Quality

Recharge Groundwater

Advantages to Living in a Floodplain

Provide Fertile Soil for Farming

Provide Ample Water for Irrigation

Provide Flat Land for Crops, Buildings, Highways

and Railroads

Availability of Nearby Rivers for Transportation

and Recreation

World’s Largest Floodshttp://pubs.usgs.gov/circ/2004/circ1254/

Flood Frequency Curve

Fig. 15-20b, p. 475

Note: Meteorologists typically watch for 2, 5, 10, 20 and 100 years floods.

Flood Control Methods

Dams and Reservoirs

Levees

Floodways

Floodwalls

Fig. 15-21a, p. 478

HOW USEFUL IS

DESALINATION?

Desalination, An Old Technology

Desalination Plant

Desalination Process

Uses of Desalination

Removing dissolved salts from ocean water or

from brackish ground water is called desalination

Methods include distillation

Process is expensive because it takes large

amounts of energy

Produces large quantities of wastewater

CAN CLOUD SEEDING AND TOWING

ICEBERGS IMPROVE WATER SUPPLIES?

Cloud Seeding Process

Cloud Seeding

Not useful in very dry areas were it is mostly needed

Would introduce large amounts of cloud-seeding chemical into the water system, possibly harming people, wildlife and agricultural productivity

Many legal disputes over clouds ownership between states

HOW CAN WE WASTE

LESS WATER?

Reducing Water Waste

65-70% of water use by people is lost through

evaporation

Decrease the burden of wastewater plants

Reduce the need for expensive dams and water transfer

project that destroy wildlife habitats and displace people

Slow depletion of groundwater aquifers

Save energy and money

Reducing Water Usage in Agriculture

• Redesign manufacturing processes

• Landscape yards with plants that require little water

• Use drip irrigation

• Fix water leaks

• Use water meters and charge for all municipal

water use

• Raise water prices

• Require water conservation in water-short cities

• Use water-saving toilets, showerheads, and front-

loading clothes washers

• Collect and reuse household water to irrigate lawns

and nonedible plants

• Purify and reuse water for houses, apartments, and

office buildings

Xerascaping

HOW CAN WE USE WATER

MORE SUSTAINABLY?