Water What is it good for…
clean drinking water 1.2 Billion liters clean drinking water a day (320 Million gallons) agricultural / industrial water 1.8 Trillion liters agricultural / industrial water a day That's 6000 liters/day (1600 gallons) per person in N.A. For comparison: World average 1800 liters/day China about 1100 liters/day We use about 400 liters/day for personal use vs. World average 90 liters/day Use doubled in US from (with population growth) North America Uses...
This water needs to be present and clean Therefore we need to measure water quantity and water quality in order to understand where problems lie Water can be “renewable” if Use < Recharge Water can be “renewable” if Pollution < Cleanup Water for Human Use
Instream use Instream use: Navigation, fish and wildlife, recreational uses Offstream use Offstream use: Removal or diversion from its SW or GW sources temporarily - e.g., irrigation, thermoelectric, industrial use Consumptive use Consumptive use: Type of offstream use of water without intermediate return to the SW or GW - e.g., transpiration and human use *SW=Surface Water, GW=Ground Water Water Use (SW & GW)*
Problems Arise From… Not Enough Water Too Much Water Degraded (Polluted) Water Not Enough Water Too Much Water Degraded (Polluted) Water
Water Use
Water Use in Agriculture 1 kg of:Requires __ liters water potatoes500 wheat900 corn1400 rice1900 broiler chicken3,500 beef100, ,000 1 Quarter Pounder = 3,000 gallons water!
Water Use in Industry Energy Industry Coal Power Plant m 3 of water/person/year Hydroelectric (in an arid region) 410 m 3 of water/person/year (evaporation)
Home Water Use
Measured in: Gallons Liters (1 gallon = 3.8 liters) Cubic meter (m 3 )- 264 gallons
Water on the Earth
10.1 Recharge rate vs. Withdrawal rate Rate of pollution vs. Rate of cleaning Global Water Supply
Hydrologic Cycle Sun Evaporation Sublimation Transpiration Precipitation
Hydrologic Cycle Sun Net movement of clouds toward land Extra water on land…
Hydrologic Cycle Sun Surface Water Runoff Groundwater Flow & Discharge Infiltration Water Returns to Ocean
Global Precipitation
Available Water Annual Precipitation Runoff Potential Evapotranspiration All 3 factors together Local water supply
Too Much Water “Normal” (1988)Floods (1993) Mississippi River (near St. Louis, MO)
New Orleans Lake Pontchartrain Mississippi River ”A land between earth and sea, belonging to neither and alternately claimed by both." - Kolb and Van Topik
Sea Level
Erosion & Subsidence: Loss of Coastal Marshes All told, more than 600,000 acres of wetlands have been lost in recent decades. Erosion rates as high as 40 acres in a day have been recorded.
Water Shortages Water Scarce (<1000 m 3 /yr/person) Water Stressed ( m 3 /yr/person)
Water Conflict Earliest Recorded (2500 B.C.): Border dispute between Lagash and Umma. Water diverted via canals. 1672: French invade Netherlands. Dutch open the dikes and create an impenetrable flood barrier : Pipeline diverting water to L.A. repeatedly bombed to protect local water supply : Hydroelectric dams repeatedly bombed during WWII. 1967: Israel takes over the Golan Heights to secure water supply from the Jordan River.
Water Politics Trade in Food International Agreements
Where does our water come from? Surface Water (0.4% of all freshwater) Groundwater (12% of all freshwater)
infiltration Amount of infiltration depends on: 1.Surface materials Promoted by pore space of soils, sand, gravel (Clay or crystalline bedrock = More runoff) 2.Vegetation Heavy vegetation = Rain doesn’t reach ground before evaporating Roots promote infiltration for water reaching ground 3.Topography Steeper = More runoff (can only infiltrate so fast) 4.Rate of precipitation Drought = No/little recharge (may be seasonal) Lots of rain = Saturates soil, promotes runoff (can only move through ground so fast) Infiltration vs. Runoff
“Ratio of 4” means “Flooding is 4 times more common after this amount of urbanization” (about 50%) Luna Leopold, 1968, USGS Circular 559
Effects of Land-Use Changes