Core Case Study: Water Conflicts in the Middle East - A Preview of the Future Many countries in the...

Core Case Study: Water Conflicts in Core Case Study: Water Conflicts in the Middle East - A Preview the Middle East - A Preview

of the Futureof the Future Many countries in Many countries in

the Middle East, the Middle East, which has one of which has one of the world’s highest the world’s highest population growth population growth rates, face water rates, face water shortages.shortages.

Figure 14-1Figure 14-1

Water Conflicts in the Middle East: A Water Conflicts in the Middle East: A Preview of the FuturePreview of the Future

Most water in this dry region comes from the Most water in this dry region comes from the Nile, Jordan or Tigris rivers.Nile, Jordan or Tigris rivers.

Countries are in disagreement as to who has Countries are in disagreement as to who has water rights.water rights.

Currently, there are no cooperative Currently, there are no cooperative agreements for use of 158 of the world’s 263 agreements for use of 158 of the world’s 263 water basins that are shared by two or more water basins that are shared by two or more countries.countries.

WATER’S IMPORTANCE, WATER’S IMPORTANCE, AVAILABILITY, AND RENEWALAVAILABILITY, AND RENEWAL

Water Water keeps us alivekeeps us alive moderates climatemoderates climate sculpts the landsculpts the land removes and dilutes wastes and pollutantsremoves and dilutes wastes and pollutants moves continually through the hydrologic cycle.moves continually through the hydrologic cycle.

Only about 0.02% of the earth’s water supply Only about 0.02% of the earth’s water supply is available to us as liquid freshwater.is available to us as liquid freshwater.


ComparisoComparison of n of population population sizes and sizes and shares of shares of the world’s the world’s freshwater freshwater among the among the continents.continents.



precipitation precipitation infiltrates the ground and is stored in soil and infiltrates the ground and is stored in soil and

rock (groundwater)rock (groundwater) EvaporatesEvaporates runs off (surface runoff) into bodies of waterruns off (surface runoff) into bodies of water

• The land from which the surface water drains into a The land from which the surface water drains into a body of water is called its body of water is called its watershedwatershed or or drainage drainage basinbasin..

Fig. 14-3, p. 308

Unconfined Aquifer Recharge Area

Precipitation Evaporation and transpiration Evaporation

Confined Recharge Area

Runoff

Flowing artesian well

Recharge Recharge Unconfined Unconfined AquiferAquifer

Stream Well requiring a pumpInfiltration Water

table LakeInfiltration

Unconfined aquifer

Confined aquiferConfining impermeable rock layer Confining impermeable rock layer

Less permeable Less permeable material such as claymaterial such as clay


We currently use more than half of the We currently use more than half of the world’s reliable runoff of surface water and world’s reliable runoff of surface water and could be using 70-90% by 2025.could be using 70-90% by 2025.

About 70% of the water we withdraw from About 70% of the water we withdraw from rivers, lakes, and aquifers is not returned to rivers, lakes, and aquifers is not returned to these sources.these sources.

Irrigation is the biggest user of water (70%), Irrigation is the biggest user of water (70%), followed by industries (20%) and cities and followed by industries (20%) and cities and residences (10%).residences (10%).

Water in the Water in the United StatesUnited States

Average Average precipitation (top) precipitation (top) in relation to in relation to water-deficit water-deficit regions and their regions and their proximity to proximity to metropolitan areas metropolitan areas (bottom).(bottom).


Fig. 14-4a, p. 309

Average annual precipitation (centimeters)

More than 122

Less than 41 81–122

41–81

Fig. 14-4b, p. 309

Acute shortage

Metropolitan regions with population greater than 1 million

Shortage

Adequate supply

Case Study: Freshwater Resources in Case Study: Freshwater Resources in the United Statesthe United States

17 western states 17 western states by 2025 could face by 2025 could face intense conflict over intense conflict over scarce water scarce water needed for urban needed for urban growth, irrigation, growth, irrigation, recreation and recreation and wildlife.wildlife.


TOO LITTLE FRESHWATERTOO LITTLE FRESHWATER

About 41% of the world’s population lives in About 41% of the world’s population lives in river basins that do not have enough river basins that do not have enough freshwater.freshwater.

Many parts of the world are experiencing:Many parts of the world are experiencing: Rivers running dry.Rivers running dry. Lakes and seas shrinking.Lakes and seas shrinking. Falling water tables from overpumped aquifers.Falling water tables from overpumped aquifers.

Stress on the World’s River BasinsStress on the World’s River Basins

Comparison of the amount of water available Comparison of the amount of water available with the amount used by humans.with the amount used by humans. Figure 14-6Figure 14-6

Case Study: Who Should Own and Case Study: Who Should Own and Manage Freshwater ResourcesManage Freshwater Resources

There is controversy over whether water There is controversy over whether water supplies should be owned and managed by supplies should be owned and managed by governments or by private corporations.governments or by private corporations.

European-based water companies aim to European-based water companies aim to control 70% of the U.S. water supply by control 70% of the U.S. water supply by buying up water companies and entering into buying up water companies and entering into agreements with cities to manage water agreements with cities to manage water supplies.supplies.

TOO LITTLE FRESHWATERTOO LITTLE FRESHWATER

Cities are outbidding farmers for water Cities are outbidding farmers for water supplies from rivers and aquifers.supplies from rivers and aquifers.

Countries are importing grain as a way to Countries are importing grain as a way to reduce their water use.reduce their water use.

More crops are being used to produce More crops are being used to produce biofuels.biofuels.

Our water options are:Our water options are: Get more water from aquifers and riversGet more water from aquifers and rivers desalinate ocean waterdesalinate ocean water waste less waterwaste less water

WITHDRAWING GROUNDWATER WITHDRAWING GROUNDWATER TO INCREASE SUPPLIESTO INCREASE SUPPLIES

Most aquifers are renewable resources Most aquifers are renewable resources unless water is removed faster than it is unless water is removed faster than it is replenished or if they are contaminated.replenished or if they are contaminated.

Groundwater depletion is a growing problem Groundwater depletion is a growing problem mostly from irrigation.mostly from irrigation. At least one-fourth of the farms in India are being At least one-fourth of the farms in India are being

irrigated from overpumped aquifers.irrigated from overpumped aquifers.

Fig. 14-7, p. 313

Trade-Offs

Withdrawing Groundwater

Advantages Disadvantages

Useful for drinking and irrigation

Aquifer depletion from overpumping

Available year-round

Sinking of land (subsidence) from overpumping

Exists almost everywhere

Polluted aquifers for decades or centuries

Renewable if not overpumped or contaminated

Saltwater intrusion into drinking water supplies near coastal areas

Reduced water flows into surface waters

No evaporation losses

Cheaper to extract than most surface waters

Increased cost and contamination from deeper wells

Groundwater Depletion: Groundwater Depletion: A Growing ProblemA Growing Problem

The Ogallala, the world’s largest aquifer, is The Ogallala, the world’s largest aquifer, is most of the red area in the center (Midwest).most of the red area in the center (Midwest).

Areas of Areas of greatest greatest aquifer aquifer depletion depletion from from groundwater groundwater overdraft in overdraft in the the continental continental U.S.U.S.


Other Effects of Groundwater Other Effects of Groundwater OverpumpingOverpumping Groundwater Groundwater

overpumping overpumping can cause can cause land to sink, land to sink, and and contaminate contaminate freshwater freshwater aquifers near aquifers near coastal areas coastal areas with saltwater.with saltwater.


Other Effects of Groundwater Other Effects of Groundwater OverpumpingOverpumping

Sinkholes Sinkholes form when form when the roof of an the roof of an underground underground cavern cavern collapses collapses after being after being drained of drained of groundwater.groundwater.


Groundwater Pumping in Saudi Groundwater Pumping in Saudi Arabia (1986 – 2004)Arabia (1986 – 2004)

Irrigation systems from the nonrenewable aquifer appear as Irrigation systems from the nonrenewable aquifer appear as green dots. Brown dots are wells that have gone dry.green dots. Brown dots are wells that have gone dry. Figure 14-9Figure 14-9

Fig. 14-12, p. 316

Solutions

Groundwater Depletion

Prevention Control

Waste less water Raise price of water to discourage waste

Subsidize water conservation

Ban new wells in aquifers near surface waters

Tax water pumped from wells near surface waters

Buy and retire groundwater withdrawal rights in critical areas

Do not grow water-intensive crops in dry areas

Set and enforce minimum stream flow levels

USING DAMS AND RESERVOIRS USING DAMS AND RESERVOIRS TO SUPPLY MORE WATERTO SUPPLY MORE WATER

Large dams and reservoirs Large dams and reservoirs produce cheap electricityproduce cheap electricity reduce downstream floodingreduce downstream flooding provide year-round water for irrigating cropland provide year-round water for irrigating cropland

displace peopledisplace people disrupt aquatic systemsdisrupt aquatic systems

Case Study: The Colorado Basin – an Case Study: The Colorado Basin – an Overtapped ResourceOvertapped Resource

The Colorado River has so many dams and The Colorado River has so many dams and withdrawals that it often does not reach the withdrawals that it often does not reach the ocean.ocean. 14 major dams and reservoirs, and canals.14 major dams and reservoirs, and canals. Water is mostly used in desert area of the U.S.Water is mostly used in desert area of the U.S. Provides electricity from hydroelectric plants for Provides electricity from hydroelectric plants for

30 million people (1/1030 million people (1/10thth of the U.S. population). of the U.S. population).

The Colorado River BasinThe Colorado River Basin

The area The area drained by this drained by this basin is equal to basin is equal to more than one-more than one-twelfth of the twelfth of the land area of the land area of the lower 48 states.lower 48 states.


Dam RemovalDam Removal

Some dams are being removed for ecological Some dams are being removed for ecological reasons and because they have outlived their reasons and because they have outlived their usefulness.usefulness. In 1998 the U.S. Army Corps of Engineers In 1998 the U.S. Army Corps of Engineers

announced that it would no longer build large announced that it would no longer build large dams and diversion projects in the U.S.dams and diversion projects in the U.S.

The Federal Energy Regulatory Commission has The Federal Energy Regulatory Commission has approved the removal of nearly 500 dams.approved the removal of nearly 500 dams.

Removing dams can reestablish ecosystems, but Removing dams can reestablish ecosystems, but can also re-release toxicants into the can also re-release toxicants into the environment.environment.

TRANSFERRING WATER FROM TRANSFERRING WATER FROM ONE PLACE TO ANOTHERONE PLACE TO ANOTHER

Transferring water can: Transferring water can: make unproductive areas more productivemake unproductive areas more productive

• Promotes:Promotes: InvestmentInvestment JobsJobs Strong economyStrong economy

cause environmental harmcause environmental harm• encourages unsustainable use of waterencourages unsustainable use of water

Case Study: The Aral Sea DisasterCase Study: The Aral Sea Disaster

Aral Sea Aral Sea once the world’s 4once the world’s 4thth largest freshwater lake largest freshwater lake Figure 14-17Figure 14-17

Case Study: The Aral Sea DisasterCase Study: The Aral Sea Disaster

Diversion of water from the Aral Sea and its Diversion of water from the Aral Sea and its two feeder rivers two feeder rivers Used for irrigationUsed for irrigation

created a major ecological, economic, and health created a major ecological, economic, and health disasterdisaster• About 85% of the wetlands have been eliminatedAbout 85% of the wetlands have been eliminated• roughly 50% of the local bird and mammal species roughly 50% of the local bird and mammal species

have disappearedhave disappeared• the sea’s salinity has tripled the sea’s salinity has tripled • water has dropped by 22 meters water has dropped by 22 meters

causing 20 of the 24 native fish species to go extinctcausing 20 of the 24 native fish species to go extinct

DESALTING SEAWATER, SEEDING DESALTING SEAWATER, SEEDING CLOUDS, AND TOWING ICEBERGS CLOUDS, AND TOWING ICEBERGS

AND GIANT BAGGIESAND GIANT BAGGIES Removing salt from seawater by current Removing salt from seawater by current

methods is methods is expensiveexpensive and produces large and produces large amounts of salty amounts of salty wastewaterwastewater that must be that must be disposed of safelydisposed of safely DistillationDistillation: :

• heating saltwater until it evaporates, leaves behind heating saltwater until it evaporates, leaves behind waste in solid form.waste in solid form.

Reverse osmosisReverse osmosis::• uses high pressure to force saltwater through a uses high pressure to force saltwater through a

membrane filter.membrane filter.

INCREASING WATER SUPPLIES BY INCREASING WATER SUPPLIES BY WASTING LESS WATERWASTING LESS WATER

We waste about two-thirds of the water we We waste about two-thirds of the water we use, but we could cut this waste to 15%use, but we could cut this waste to 15% 65-70% of the water people use throughout the 65-70% of the water people use throughout the

world is lost through evaporation, leaks, and world is lost through evaporation, leaks, and other lossesother losses

Water is underpriced through government Water is underpriced through government subsidiessubsidies

The lack of government subsidies for improving The lack of government subsidies for improving the efficiency of water use contributes to water the efficiency of water use contributes to water wastewaste

INCREASING WATER SUPPLIES BY INCREASING WATER SUPPLIES BY WASTING LESS WATERWASTING LESS WATER

60% of the world’s irrigation water is currently 60% of the world’s irrigation water is currently wastedwasted improved irrigation techniques could cut this improved irrigation techniques could cut this

waste to 5-20%waste to 5-20% Center-pivot, low pressure sprinklers sprays Center-pivot, low pressure sprinklers sprays

water directly onto cropwater directly onto crop It allows 80% of water to reach cropIt allows 80% of water to reach crop Has reduced depletion of Ogallala aquifer in Has reduced depletion of Ogallala aquifer in

Texas High Plains by 30%.Texas High Plains by 30%.

Fig. 14-18, p. 325

Center pivotCenter pivot

Drip irrigationDrip irrigation

Gravity flowGravity flow(efficiency 60% and

80% with surge valves)

Above- or below-ground pipes or tubes deliver water to individual plant roots.

Water usually comes from an aqueduct system or a nearby river.

(efficiency 90–95%)

(efficiency 80%–95%)

Water usually pumped from underground and sprayed from mobile boom with sprinklers.

TOO MUCH WATERTOO MUCH WATER

Human activities have contributed to flood Human activities have contributed to flood deaths and damages.deaths and damages. Figure 14-23Figure 14-23

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