1. Chapter 11 Water

2. Section 1 – Water Resources

3. The Water Cycle

4.  Evaporation –Heat of the sun changes water on the Earth’s surface from liquid to gas.  Condensation –Water vapor cools enough to return to a liquid state.  Precipitation –Liquid or solid water falls from the clouds to the Earth.  Transpiration –Plants release water vapor from their leaves into the air. Major Processes in Water Cycle

5. Global Water Distribution  3% Freshwater: 97% Saltwater

6. Surface Water  Fresh water on Earth’s land surface  Found in lakes, rivers, streams, and wetlands  Provide drinking water, water for crops, food, power for industry, and means of transportation  River Systems – as streams and rivers move across the land they form this flowing network of water

7.  Watershed – a region drained by, or one that contributes water to, a stream, lake, or other body of water.  Divide – Any ridge between two streams along which precipitation runs off. –Continental Divide

8. Groundwater  Water beneath the Earth’s surface in sediment and rock formations.  Water table – as water travels beneath the Earth’s surface, it eventually reaches a level where rocks and soil are saturated with water –Wet regions – may be at Earth’s surface –Deserts – hundreds of meters below Earth’s surface

9.  Aquifers – an underground formation containing groundwater  Porosity – the percentage of the total volume of a rock that has spaces (holes)  Permeability – the ability of rock or soil to allow water to flow through it.  The Recharge Zone – an area of the Earth’s surface from which water percolates down into an aquifer. –Environmentally sensitive areas. –Aquifers can take tens of thousands of years to recharge.  Wells – a hole that is dug or drilled to reach groundwater

11. Section 2 – Water Use and Management

12. Global Water Use  Three major uses for water: residential use, agricultural use, and industrial use –Most fresh water used to irrigate crops

13. Residential Water Use  The average person in the US uses about 80 gallons of water every day. –In India – 41 Liters = ~11 gallons  Water Treatment –Potable – water that is safe to drink –Pathogens – Organisms that cause illness or disease that are removed during the water treatment process.

15. Industrial Water Use  Industry accounts for 19% of water used in the world. –Most used to cool power plants.

16. Agricultural Water Use  Irrigation – a method of providing plants with water from sources other than direct precipitation.

17. 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. –Colorado River  Dams and Reservoirs –Dam – a structure built across a river to control the river’s flow –Reservoir – when a river is dammed, and artificial lake forms behind the dam.

18. Water Conservation  In Agriculture – Drip irrigation systems – deliver small amounts of water directly to roots of plants  In Industry – recycling of cooling water and wastewater. Instead of discharging into a river, businesses recycle water.  At Home – Low-flow toilets and shower heads

19. Solutions for the Future  Desalination – the process of removing salt from salt water.  Transporting Water – Greek Islands water usage has increased due to tourists. Water is shipped in regularly from the mainland in plastic bags.

20. Section 3 – Water Pollution

21. 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. –Industrialization and rapid human population growth

22. Point-Source Pollution  Pollution discharged from a single point –Can be identified and traced to the source –Factory, wastewater treatment plant, leaking oil tanker

23. Non-Source Pollution  Comes from different sources and are often difficult to identify. –If a farm, a road, or any other land surface in a watershed is polluted, runoff from a rainstorm can carry the pollution into a nearby river, stream or lake. –Spraying lawn chemicals, use of storm drains to dispose of used motor oil

24. Principal Water Pollutants  Wastewater – water that contains wastes from homes or industry.  Treating wastewater – –Filtration – wastewater passed through large screen to remove solid objects –First settling tank – wastewater sent into large tank, where smaller particles sink to the bottom and form sewer sludge –Aeration tank – mixed with oxygen and bacteria. Bacteria use oxygen and feed on wastes –Second settling tank – bacteria removed from sludge –Chlorination or UV light– Chlorine added to disinfect water or UV used to disinfect water.

26.  Sewage sludge – product of wastewater treatment. –Often incinerated, and then ash is buried in secure landfill. –If toxicity can be reduced to safe levels – sold as fertilizer. –Also combined with clay to make bricks.

27. Principal Water Pollutants, cntd.  Thermal Pollution – when the temperature of a body of water increases. Leads to decrease in oxygen. –Power plants release warm water into a lake or river –Massive fish kills  Groundwater Pollution – any pollution of the surface water can affect groundwater –Herbicides, chemical fertilizers, underground storage tanks

28. Ocean Pollution  Oil spills – 1989 Exxon Valdez oil spill in Prince William Sound, Alaska.  125 Olympic-sized swimming pools of oil dumped into Ocean

29. Ocean Pollution Deep Horizon Oil Spill – Largest accidental marine oil spill in the history of the petroleum industry.  Flowed unabated for three months in 2010 –Skimmer ships, floating containment booms, anchored barriers, sand-filled barricades along shorelines, and dispersants were used in an attempt to protect hundreds of miles of beaches, wetlands, and estuaries from the spreading oil. – –Even the amount of oil that was spilled remains a mystery.   Federal officials estimated the amount at more than 200 million gallons of crude, while acknowledging the estimate could be off by plus or minus 20 million gallons.   BP, which leased the Deepwater Horizon rig, argued in December that the government’s oil spill size estimate was 20% to 50% too high. Deepwater Horizon oil spill - May 24, 2010

31. Cleaning Up Water Pollution  Clean Water Act of 1972 – to restore and maintain the chemical, physical, and biological integrity of the nation’s waters –Set a national goal of making all natural surface water fit for swimming and fishing by 1983. –Banned pollutant discharge into surface water after 1985.