The Hydrosphere Water Resources IB Syllabus 3 6

The Hydrosphere: Water Resources IB Syllabus: 3. 6. 1 – 3. 6. 2 Chapter: 14 Video: Blue Gold Do water use surveys

Syllabus Statements 3. 6. 1: Describe the Earth’s water budget n 3. 6. 2: Describe and evaluate the sustainability of freshwater resource usage n

Water use stats n http: //www. worldometers. info/

The story of bottled water n http: //www. inhabitat. com/2010/03/22/annieleonard-releases-the-story-of-bottled-water-onworld-water-day/

Water, water everywhere and not a drop to drink We cannot live without water n So much focus on wars over oil, ethnicity, religion, resources etc. but the major point of future conflict might be water n Indus River shared by India and Pakistan n Tigris –Euphrates Rivers Turkey, Syria, Iraq n Jordan River Israel, Palestine, Jordan, n International Water use agreements must be forged for the future political stability of the regions n

Indus River: already unstable, what future change might exacerbate it?

Basic water facts 71% of the earth’s surface n Most organisms 50 – 60% water n Necessary for survival n Sculpts the earth’s surface n Moderates global climate n Dilutes pollutants n

Water’s properties n n n n Hydrogen bonding Liquid form for large temperature range High heat capacity Lots of heat for evaporation Universal Solvent Filters UV radiation High surface tension Expands when frozen

Fresh water 97. 4% of water is saline n Remaining 2. 6% fresh water n 80% is in ice caps & glaciers n 0. 59% inaccessible ground water n Remaining 20% of fresh water is in lakes, soil water, water vapor, rivers and biota in order of decreasing amount stored n 0. 014% of the total available for use n Patchy distribution on earth Canada = 20% of total, China = 7% n

All water Fresh water Readily accessible fresh water Groundwater 0. 592% Biota 0. 0001% Rivers 0. 0001% Lakes 0. 007% Oceans and saline lakes 97. 4% Fresh water 2. 6% 0. 014% Ice caps and glaciers 1. 984% Soil moisture 0. 005% Atmospheric water vapor 0. 001%

Sources Surface water 1. - - - Precipitation that does not infiltrate the ground or return to atmosphere Forms wetlands, lakes, rivers & resevoirs 1/3 of total runoff = reliable runoff a steady source of water Watershed or drainage basin is a region of runoff flowing into a surface water body

Sources Groundwater 2. - - Precipitation infiltrates, percolates and fills voids in soil and rock Zone of saturation = depth where voids are filled Top of zone of saturation is water table Above = zone of aeration Porous layers where groundwater flows are aquifers Recharge zone = area where water returns to aquifer

Flowing artesian well Unconfined Aquifer Recharge Area Evaporation and transpiration Well requiring a pump Precipitation Evaporation Confined Recharge Area Runoff Aquifer Infiltration Stream Water table Infiltration Lake Unconfined aquifer Less permeable material such as clay Confined aquifer Confining permeable rock layer

Our water withdrawal Now withdrawing 35% of world reliable runoff n 20% left in streams for n n Transport goods, dillute pollution, sustain wildlife Global withdrawal will double in two decades n Will exceed availability in some areas n Water delivery does not match with population requirements n Asia 61% of people 36% reliable runoff n South America 6% people 26% reliable runoff n

5, 500 Water use (cubic kilometers per year) 5, 000 Total use 4, 500 4, 000 3, 500 3, 000 2, 500 2, 000 Agricultural use 1, 500 Industrial use 1, 000 Domestic use 500 1920 1940 1960 Year 1980 2000

World water use n Worldwide 70% of reliable water from surface and ground for Irrigation n 18% of crop land producing 40% of world food Industry uses 20% n Residential use 10% n n Consumptive water use water not reusable in basin it came from – evaporation or pollution

United States Power cooling 38% Agriculture 41% Industry 11% Public 10% China Agriculture 87% Public 6% Industry 7%

U. S. case study Plenty of freshwater available n But… n in wrong place at wrong time n Contaminated by agricultural and industrial processes n n EAST – used for energy & manufacturing n n Problems with flooding, urban shortage WEST - irrigation n Problems with low precipitation, high evaporation

400, 000 liters (106, 000 gallons) 1 automobile 1 kilogram cotton 10, 500 liters (2, 400 gallons) 1 kilogram aluminum 9, 000 liters (2, 800 gallons) 1 kilogram grain-fed beef 7, 000 liters (1, 900 gallons) 1 kilogram rice 1 kilogram corn 1 kilogram paper 1 kilogram steel 5, 000 liters (1, 300 gallons) 1, 500 liters (400 gallons) 880 liters (230 gallons) 220 liters (60 gallons)

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

What causes freshwater shortage? Dry climate 2. Drought – precipitation 70% less than evaporation for 21+ days 3. Desication – drying of soil 4. Water stress – increased water removal CATEGORIES Water stressed = runoff person < 1, 700 m 3 Water scarcity = runoff person < 1, 000 m 3 1.

500 million people live in water stressed or scarce countries n By 2025 2. 5 - 3. 5 billion n Water far removed from population centers n Precipitation arrives in short periods or cannot be collected & stored n Global warming may further stress this system. n n How? Where plentiful supplies exist people too poor to access a safe supply n Water shortage projected to be most important environmental issue in near future n

Europe North America Asia Africa South America Stress High Australia None Stress on Major River Systems

Can we increase Freshwater supplies? 1. 2. 3. 4. 5. 6. Build dams and reservoirs to store Bring in surface water from another area Withdraw groundwater Desalinization Waste less water Import food to reduce agricultural water use

Large losses of water through evaporation Downstream cropland estuaries are deprived of nutrient-rich silt Flooded land destroys forests or cropland displaces people Downstream flooding is reduced Provides water for year-round irrigation of cropland Reservoir is useful for recreation and fishing Are Dams a good idea? Can produce cheap electricity (hydropower) Migration and spawning of some fish are disrupted

• 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 The overlooked value of rivers

The Colorado River: A case study 6 states and 2 countries depend on water from this system n Colorado River compact formed to execute interstate agreements n Divided into upper and lower basin areas n Allocated 7. 5 MAF each (million acre flow) n Lower basin almost maxed out, upper less developed and less used n Water is held behind dams and transported in aqueduct systems n Large surface area exposed for evaporation n

IDAHO WYOMING Dam Aqueduct or canal Salt Lake City Upper Basin Grand Junction Denver Lower Basin UPPER BASIN UTAH COLORADO Lake Powell Grand Canyon Las Vegas Glen Canyon Dam NEW MEXICO Boulder City ARIZONA CALIFORNIA Albuquerque Los Angeles Palm Springs San Diego Mexicali All-American Canal LOWER BASIN Phoenix Yuma Gulf of California Tucson 0 100 mi. 0 150 km MEXICO

Current growth in areas like NV will exceed ground and river water in 10 years – where will they borrow from? n Glen Canyon Dam being decomissioned to limit evaporation n River is dry by the mexican border now n Some historical droughts have limited flow to 9. 5 MAF in the entire river n n http: //ag. arizona. edu/AZWATER/arroyo/101 comm. html

China’s Three Gorges Dam World’s largest hydrologic project – dam done fully operational by 2011 n Potential output of 9 traditional power plants n Generate 10% of China’s electricity n Reduce dependence on air polluting coal n Hold back Yangtze River’s floodwaters n Reducing silting of river n

Beijing RUSSIA YELLOW SEA MONGOLIA CHINA Shanghai Jailing River Yichang Wunan Chongquing CHINA NEPAL INDIA Reservoir BHUTAN BANGLADESH VIETNAM BURMA LAOS PACIFIC OCEAN Three Gorges Dam Yangtze River EAST CHINA SEA

BUT… Huge reservoir will displace 1. 9 million people n Flood large areas of productive farmland forests n Change ecosystem n Water pollution will increase n Reduce nutrient rich sediment deposits n Salt water intrusion into drinking water n

Transferring Water Tunnels, aqueducts, underground pipes transfer water to water poor areas n Benefits & Environmental Problems n California Water Project n Pump water from north to south n Degrade environment in North to supply water to South n Already overdrawn groundwater n

CALIFORNIA NEVADA Shasta Lake Sacramento River Oroville Dam and Reservoir Feather River North Bay Aqueduct UTAH Lake Tahoe Sacramento San Francisco Fresno South Bay Aqueduct Hoover Dam and Reservoir (Lake Mead) Colorado River Los Angeles Aqueduct San Luis Dam and Reservoir ARIZONA California Aqueduct Colorado River Aqueduct Santa Barbara Central Arizona Project Los Angeles San Diego Salton Sea Phoenix Tucson MEXICO

Groundwater use Provide drinking water for 1/3 world’s people n U. S. 51% drinking water, 43% of irrigation water from aquifers n Over pumping largely since 1950 n US groundwater is being withdrawn 4 X faster than it is being replaced n Also being degraded with pollutants that leach in from agriculture & other systems n

Pros and Cons Disadvantages n n n Water table lowering Aquifer depletion Aquifer subsidence (sinkholes) Salt water intrusion Reduced stream flow Advantages n n n Tapping aquifer can be done year round Not lost by evaporation Less expensive to develop

Original water table Initial water table Cone of depression Lowered water table

Groundwater Overdrafts: High Moderate Minor or none

Subsidence: High Moderate Minor or none

Less than 61 meters (200 ft) WYOMING SOUTH DAKOTA 61 -183 meters (200 -600 ft) More than 183 meters (600 ft) (as much as 370 meters or 1, 200 ft. in places) NEBRASKA The Ogallala Aquifer KANSAS Water withdrawn 8 x faster than its replenished Northern states have ample supply Southern shortage Essentially nonrenewable resource COLORADO OKLAHOMA NEW MEXICO TEXAS 0 0 Miles 100 160 Kilometers

Coastal Aquifers - FL Freshwater withdrawn faster than its replaced Salt water intrusion n Contaminates drinking water supplies n Freshwater lens sits above denser salt water n Salt water creeps up when fresh is removed n Density prohibits freshwater returning to that space n

Major irrigation well Well contaminated with saltwater Water table Sea Level Salt water Fresh groundwater aquifer Interface Saltwater Intrusion Interface Normal Interface

Other solutions n Desalinization – 2 methods distillation & reverse osmosis 13, 300 desalinization plants worldwide n Expensive and high energy, produces brine n n Cloud seeding Fire particles into clouds to form rain n Need clouds to start, polluting the rain n

Water conservation 65% of water used is wasted through evaporation, leaks & losses n Causes of waste n Water subsidy policies – low prices discourage conservation n Water laws – legal rights of water users n Fragmented watershed management – different distributors n

Improving irrigation n 1. 2. 3. 4. 57% irrigation water never reaches target crops – flood irrigation method Center pivot low pressure sprinklers Low energy precision application Time controlled valves Soil moisture detectors water only when necessary Drip irrigation systems

Gravity Flow Drip Irrigation Center Pivot (efficiency 60% and 80% with surge valves) (efficiency 90 -95%) (efficiency 80% with low-pressure sprinkler and 90– 95% with LEPA sprinkler) Water usually comes from an aqueduct system or a nearby river. Above- or below-ground pipes or tubes deliver water to individual plant roots. Water usually pumped from underground and sprayed from mobile boom with sprinklers.

• Lining canals bringing water to irrigation ditches • Leveling fields with lasers • Irrigating at night to reduce evaporation • Using soil and satellite sensors and computer systems to monitor soil moisture and add water only when necessary • Polyculture • Organic farming • Growing water-efficient crops using droughtresistant and salt-tolerant crop varieties • Irrigating with treated urban waste water • Importing water-intensive crops and meat Reducing waste water in irrigation

• 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 frontloading clothes washers • Collect and reuse household water to irrigate lawns and nonedible plants • Purify and reuse water for houses, apartments, and office buildings Reducing waste in Homes, Industry & Businesses

Xeriscaping – water conserving landscape for the home

Too much water Flooding is a natural process n Area near streams is floodplain – highly productive n Wetlands usually provide flood control n Humans have n Removed water absorbing vegetation n Drained flood absorbing wetlands n Built cities in floodplains n

Reservoir Dam Levee Floodplain Flood wall

Oxygen released by vegetation Diverse ecological habitat Evapotranspiration Trees reduce soil erosion from heavy rain and wind Steady river flow Leaf litter improves soil fertility Tree roots stabilize soil and aid water flow Forested Hillside Agricultural land Vegetation releases water slowly and reduces flooding

Tree plantation Evapotranspiration decreases Roads destabilize hillsides Ranching accelerates soil erosion by water and wind Winds remove fragile topsoil Agriculture land is flooded and silted up Gullies and landslides Heavy rain leaches nutrients from soil and erodes topsoil After Deforestation Silt from erosion blocks rivers and reservoirs and causes flooding downstream Rapid runoff causes flooding

Extremely severe Very severe Moderately severe Somewhat severe Not severe

• Not depleting aquifers • Preserving ecological health of aquatic systems • Preserving water quality • Integrated watershed management • Agreements among regions and countries sharing surface water resources • Outside party mediation of water disputes between nations • Marketing of water rights • Wasting less water • Decreasing government subsides for supplying water • Increasing government subsides for reducing water waste • Slowing population growth Sustainability of Water in our Future

Hydrologic Cycle