Chapter 9 Water Resources

The Debate on the Klamath River

Dams on the Klamath built for hydroelectric power

The Klamath River was once a spectacular habitat for Salmon.

Let’s view the story of the Klamath River klamath-river/mclain-photography klamath-river/mclain-photography

Distribution of water on Earth

Water is abundant, but usable water is rare! Fresh water represents less than 3% of all water on Earth and only about ¾ of that water is surface water. Most of the surface water is frozen as ice and in glaciers; less than 1% is usable by us. A small fraction of aboveground water is found in the atmosphere and the rest is found in lakes, streams, rivers and wetlands.

Groundwater Groundwater exists in the many small spaces found within the permeable layers of rock and sediment called aquifers Unconfined aquifers-porous rock covered by soil, water can flow easily in and out. Confined aquifers-aquifers surrounded by impenetrable rock or clay that impedes water flow to or from the aquifer. Water table- water in a given area fully saturates the rock or soil, the surface of the groundwater in an area.

Aquifers

The Ogallala Aquifer- the largest aquifer in the US, found in the Great Plains

Confined AquiferUnconfined Aquifer Recharged very slowly (10, ,000 yrs) Recharged often through precipitation Much older water and is less likely to be contaminated by anthropogenic chemicals Water is likely to be contaminated with chemicals and pollution Unsustainable large scale use When the rate of recharge does not keep pace with the rate of withdrawal, water runs out

Groundwater recharge- when rain percolates through the soil and goes into an aquifer. Confined aquifers need an opening at the land’s surface that can serve as a recharge area. Springs bring water up from the aquifers to the surface and become freshwater aquatic biomes. Artesian wells- a hole is drilled into a confined aquifer, releasing the pressure on the water, and the water rises up in the well.

Salt water Intrusion

Surface Water Exists above the ground and includes lakes, streams, rivers, ponds, and wetlands. 3 largest rivers in the world= The Amazon, the Congo, and The Yangtze. Land surrounding rivers is often highly fertile. During heavy rainfall, the riverbanks overflow onto to the adjacent land (floodplain) and deposit nutrient rich sediment onto the soil.

The largest lakes in the world. Lake Continent Length in Miles 1 Caspian Sea Asia-Europe 143, Superior North America 31, Victoria Africa 26, Huron North America 23, Michigan North America 22, Aral Sea Asia 13, Tanganyika Africa 12, Baykal Asia 12, Great Bear North America 12, Nyasa (Malawi) Africa 11,150360

Lake Types Oligotrophic- low productivity due to low amounts of nutrients such as P and N 2 Mesotrophic-have moderate levels of productivity Eutrophic- have high levels of productivity

Atmospheric Water People rely on precipitation! Droughts destroy crops, kill livestock, and causes million of people to go hungry. The cycling of nutrients important to ecosystem productivity, such as P and N 2 depends on the movement of water and thus soil fertility.

The Dust Bowl of 1935 Severe and prolonged drought, caused decades of crop failure. With few crops to hold the topsoil in place, the drought led to massive dust storms.

Flooding Excess water due to human activity such as overdevelopment, also can lead to flooding.

Levees and Dams-alter the availability of water and prevent rivers from flowing over their banks onto the floodplain.

Breached Levee in New Orleans during Hurricane Katrina

Dams- like the Hoover Dam is a barrier that runs across a river or stream to control the flow of water.

Three Gorges Dam Video World’s largest Dam, took 13 years to build, and flooded 13 cities, 140 towns, and 1350 villages forcing over 1.3 million people to be displaced.

Dikes are built to prevent ocean waters from adjacent land.

Fish Ladders- have been added to some dams so migrating fish can return to their breeding grounds.

Aqueducts-are canals or ditches used to carry water from one location to another.

The Desalination Process is used when some water poor countries need fresh water (Middle East) Desalination techniques include distillation and reverse osmosis

Household Water Consumption Bath A full tub is about 36 gallons. Shower 2 gallons/min. Old shower heads used 5 gallons/min Teeth brushing <1 gallon, especially if water is turned off while brushing. Newer bath faucets use 1 gallon/min, older models 2 gallons/min Hands/face washing 1 gallon Face/leg shaving 1 gallon Dishwasher 4 to 10 gallons/load, depending of efficiency of dishwasher Dishwashing by hand: 20 gallons. Newer kitchen faucets use about 2.2 gallons/ min Clothes washer 25 gallons/load for newer washers. Older models use about 40 gallons per load. Toilet flush 3 gallons. Most all new toilets use 1.6 gallons per flush. Glasses of water drunk 8 oz. per

Types of Irrigation Furrow irrigation-65% efficient Spray irrigation % efficient Flood Irrigation-70-80% efficient Drip Irrigation-over 95% efficient

Hydroponics

50% of water goes towards generating electricity Nuclear power plants generate one fifth of the electricity produced in the United States. The nuclear power cycle uses water in three major ways: extracting and processing uranium fuel, producing electricity, and controlling wastes and risks..

Inside a nuclear power plant

Xeriscape for water conservation

How else can we conserve water? 1. Produce more efficient manufacturing equipment. 2. Collect rainwater on surfaces of buildings. 3. Use waste water for irrigation 4. Use water saving devices in sinks and showers 5. Reuse grey water 5. Use xeroscape landscaping