Soil Water

Homework I5 Bonus Points Posted on the website Answers must be typed Exam on Monday, September 24

Water as a Resource

CIA Global Trends: Natural Resources and Environment (projections for 2015) Overall food production will be adequate to feed the world's growing population, but poor infrastructure and distribution, political instability, and chronic poverty will lead to malnourishment in parts of Sub-Saharan Africa. The potential for famine will persist in countries with repressive government policies or internal conflicts. Despite a 50 percent increase in global energy demand, energy resources will be sufficient to meet demand; the latest estimates suggest that 80 percent of the world's available oil and 95 percent of its gas remain underground. In contrast to food and energy, water scarcities and allocation will pose significant challenges to governments in the Middle East, Sub-Saharan Africa, South Asia, and northern China. Regional tensions over water will be heightened by 2015.

Very Low < 2000 m 3 / year Catastrophic < 1000 m 3 /year ½ World Population Water Stressed gal/day per person 126 gal/day Floridians? In the developing world, 80 percent of water usage goes into agriculture 2015

Agriculture and Development 1 ton of grain = ______ tons water In the developing world, 80 percent of water usage goes into agriculture

The water table under some of the major grain-producing areas in northern China is falling at a rate of five feet per year, and water tables throughout India are falling an average of 3-10 feet per year.

½ China’s wheat, 1/3 corn Levels dropping 10 ft. or more / year Shift to Deep fossil aquifer (non-replenishable) Agricultural well depths can exceed 1000 feet ($) Municipal well depths can exceed 3000 ft. Shallow aquifer largely depleted (replenishable) China’s grain production has fallen from its historical peak of 392 million tons in 1998 to an estimated 358 million tons in 2005, a drop of 34 million tons. China largely covered the drop-off in production by drawing down its once vast stocks until 2004, at which point it imported 7 million tons of grain.

India 21 million wells water table is falling by 6 meters (20 feet) per year falling water tables have dried up 95 percent of the wells owned by small farmers drilling 1000m to reach water agriculture is rain-fed and drinking water is trucked in Population Pakistan is growing by 3 million per year, In the Punjab plain, the drop in water tables appears to be similar to that in India. In the province of Baluchistan, water tables are falling by 3.5 meters per year. within 15 years Quetta will run out of water if the current consumption rate continues Pakistan Quetta

Cenomanian-Turonian Mountain Aquifer recharged from the West Bank highly permeable Coastal Aquifer Width between 3 and 20 km chief resource of water for Gaza depth to groundwater 60 m to 8 m Israel

sites lack infrastructure and mitigation measures

The Sahara: Libya 1953 “fossil” water Nubian Sandstone Aquifer world's largest fossil-water reserve located near the center of the world's largest continuous stretch of desert two million square kilometers equivalent to the flow of 200 years of water in the Nile River

4 major basins 20,000km³ 10,000km³ 4,800km³ The Great Man-Made River Project Water is 1/10 cost Of desalinization

The Great Man-made River Project the largest underground network of pipes in the world 1300 wellsmore than 500 m deepm 6,500,000 m³ water/day Tripoli, Benghazi, Sirt

1984 Saudi national survey reported fossil water reserves at 462 billion tons ½ has been depleted irrigated agriculture could last for another decade al-Disi aquifer sandstone aquifer not subject to recharge Saudi Arabia Partly in Jordan

U.S. Water Rainfall: 4,200 billion gal/day 408 billion gallons per day total withdrawal Thermoelectric power = 50% Irrigation = 30% Public-supply = 10% Industrial = 5%

Unconsolidated: sand and gravel Ogallala saturated thickness ranges from a few feet to more than 525 feet thick thin

How much water do you use?

UseGallons per Capita Percentage of Total Daily Use Showers % Clothes Washers % Dishwashers1.01.3% Toilets % Baths1.22.1% Leaks % Faucets % Other Domestic Uses % Water Usage 74 gallonsTotal

Americans drink more than 1 billion glasses of tap water per day. On average, 50 to 70 percent of home water is used outdoors for watering lawns and gardens. Average household water use annually: 127,400 gallons Average daily household water use : 350 gallons Factoids

It takes about 4,776 gallons of water to raise a Christmas tree. To raise the 35 million Christmas trees U.S. families enjoy each year, a total of 167 billion gallons is required. If mothers refresh their floral arrangements and flowering plants during the Mothers' Day week, they will use 2,835,000 gallons of water. After Thanksgiving dinner in 1999, 16.4 million Americans watched football. At halftime, American toilets flushed 16.4 million times and used 48.5 million gallons of water. Water efficient toilets would save us 22.3 million gallons of water. Factoids

Where is all the Water?

800 miles Total Earth Water = 1.4B km km

Total Earth Water = 1.4B km 3 OceansAtmosphereLakesRiversSoilAquifer/Groundwater Ice and Glaciers 400 billion billion gallons

Total Earth Water Oceans Ice and Glaciers Aquifer/Groundwater Atmosphere AtmosphereLakesSoilRivers 97% 2.0% 0.6% 0.2% 0.012% 0.001% %

Total Earth Water Oceans Ice and Glaciers AtmosphereAquifer/GroundwaterLakesRiversSoil } 99.2% } 0.8%

Total Earth Water Oceans Ice and Glaciers AtmosphereAquifer/GroundwaterLakesRiversSoil } 3.97 x gal } 3.0 x gal

Cycling of Water in the Environment

The hydrologic cycle takes place in the hydrosphere, this is the region containing all the water in the atmosphere and on the surface of the earth. The cycle is the movement of water through this hydrosphere. Hydrologic Cycle Condensation Infiltration Runoff Evaporation Precipitation

overland flow Evaporation/Transpiration groundwater interflow Fate of Precipitation percolation infiltration