Chapter 11-Water Water Resources

Water “Water Planet”- Earth has an abundance of water in all forms: solid, liquid, and gas. Renewable resource because it is circulated in the water cycle. Humans can only survive a few days without water. Two kinds of water on Earth: Fresh water- Can drink because it contains little salt. Salt water- Ocean water with a high concentration of salt.

The Water Cycle

Global Water Distribution 97% salt water 3% fresh water 77% of fresh water frozen in icecaps and glaciers 22% ground water 1 % other

Global Water Distribution Surface water- Fresh water on Earth’s land surface. Lakes, rivers, streams, and wetlands River systems- Flowing network of water comprised of streams and rivers. Amazon river system- largest in the world Watershed- Area of land that is drained by a river.

Watersheds of the World

Global water Distribution Ground Water- Water stored beneath the Earth’s surface in sediment and rock formations. Water table- Level where the rocks and soil are saturated with water Aquifer- Underground formation that contains water Porosity- Amount of space between the particles that make up a rock. Permeability- The ability of rock or soil to allow water to flow through it. Permeable- Allows the flow of water. Impermeable- Does not allow the flow of water.

Ground Water- Cont’d. The Recharge Zone- The area of the Earth’s surface where water percolates down into an aquifer. Wells- A hole that is dug or drilled to reach groundwater

Water Use and Management Chapter 11-Water Water Use and Management

Global Water Use Most freshwater used globally to water crops. 19% of global water use for industry Only 8% of global water used for washing and drinking.

Residential Water Use Striking differences among countries around the world U.S. residents use on average 300 L of water per day Indian residents use on average 41 L of water per day

Water Treatment Potable- Safe to drink. Treatment must remove elements: mercury, arsenic, and lead Found in polluted and ground water Pathogens- Organisms that cause illness or disease See Figure 6, Pages 276-277

Water Treatment

Water Use Industrial- 19% of water use in world Manufacture goods Dispose of waste Generate power Most used to cool power plants Agricultural- 67% of water use in world 80% of water used in agriculture evaporates Irrigation- Method of providing plants with water from sources other than direct precipitation.

Water Use

Water Management Projects Aqueducts- Huge canals that brought water from the mountains to dry areas. Dams and water diversion canals used today. Water management projects today: Bring in water to make a dry area habitable Create a reservoir for recreation or drinking water Generate electric power

Water Management Projects Water Diversion Projects- To supply dry regions with water, all or part of a river can be diverted into canals that carry water across great distances.

Water Management Projects Dam- Structure built across a river to control the river’s flow. Can be used to generate electricity. Problems: flooding, ecosystem destruction, and dam failure Fertile sediment builds up behind dams Reservoir- Artificial lake formed behind a dam.

Water Conservation Water becomes more expensive as it depletes. Agriculture: Most water loss from evaporation, seepage, and runoff Drip Irrigation System- Small amounts of water delivered directly to roots using perforated tubing.

Water Conservation Home: Industry: Water-saving technology such as low-flow toilets and shower heads Water lawns at night Xeriscaping- Designing landscapes that require minimal water use. Industry: Recycling of cooling water and wastewater City wide/company wide water saving plans

Solutions for the Future Desalination- Process of removing salt from salt water Heats water and collects evaporation Middle East/Kuwait has desalination plants Transporting Water Transporting in bags and/or large plastic containers from abundant supplies to low supplied regions Towing icebergs??

Chapter 11-Water Water Pollution

Water Pollution The introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water.

Types of Water Pollution Nonpoint-source Pollution Pollution that comes from many different sourecs Difficult to identify and trace/regulate and control 96% of polluted water in U.S Point-source Pollution Pollution discharged from a single source Can be identified and traced .

Pollutant Types and Sources

Wastewater Water that contains waste from homes or industry. Treating Most contaminates are biodegradable Some toxic substances cannot be removed by standard treatment

Wastewater Sewage sludge Solid material that remains after treatment Sometimes hazardous waste Often incinerated and ash buried Can be used as fertilizer or bricks

Water Pollution Eutrophication Containing an abundance of nutrients Leads to swamp or marsh Artificial Eutrophication- Sewage and fertilizer runoff enhances Ex: Algal blooms Thermal Pollution- Increased temperature of water sources caused by factories and industries cooling systems Decreases oxygen levels Kills organisms

Water Pollution Groundwater pollution- Polluted surface water percolates down to groundwater Leaking underground storage tanks are large problem Remains for 100s to 1000s of years Ocean pollution Coastal ecosystems most affected Legal to dump in some parts of ocean Oil spills 5% of ocean pollution Nonpoint-source pollution from land 10 times more than tanker spills

Oil Spills

Water Pollution Biomagnification- Accumulation of pollutants at successive levels of the food chain. Many pesticides Example: DDT and the Bald Eagle Clean Water Act of 1972- To restore and maintain the chemical, physical, and biological integrity of the nation’s waters. Goal to make fishing and swimming safe by 1983. Not achieved 30% increase Opened door for more legislation

Biomagnification

Water Quality Federal Laws