WATER

1. WATER

2. Water Resources • Describe the distribution of Earth’s water resources • Explain why fresh water is one of Earth’s limited resources • Describe the distribution of Earth’s surface water. • Describe the relationship between groundwater and surface water in a watershed.

3. Two types of water on Earth • Salt – 97% • Fresh – 3% • Icecaps and glaciers – 77% • Groundwater – 22% • Other - 1%

5. Surface Water • Fresh water on Earth’s surface • Lakes, rivers, stream, and wetlands • Provide drinking water, water for farming, power for industry and means of transportation. • Most large cities built near rivers or sources of surface water

6. River Systems • A flowing network of water • Aerial view looks like roots of tree feeding into a trunk • Mississippi, Amazon, and Nile are the largest river systems in the world • Amazon river system is the largest in the world: drains an area of land the size of Europe

7. Water Sheds • Area of land drained by a river • Snow and rain increase water in a watershed • Pollution easily spread • http://www.des.state.nh.us/organization/commissioner/pip/factsheets/wmb/documents/wmb-19.pdf

8. Water sheds of the World

9. Mississippi River Watershed • Drains water from 30 states • Covers 40% of contiguous land area of U.S. • Supplies fresh water to thousands of communities across the central U.S.

11. Where is the Water? • Canada’s hundreds of thousands of lakes make ups up about 20% of the world’s surface freshwater supply.

12. Lake Baikal in Siberia Provides about 20% world’s freshwater supply but serves only a small population of people.

13. The Amazon River contains another 20% of the world’s surface freshwater supply but only supports a small number of people.

14. Groundwater • Water beneath Earth’s surface in sediment and rock formations. • Makes up most of the fresh water that is available for human use. • Water table – level in ground where rocks and soil are saturated with water. • Has peaks and valleys that match the shape of the land.

15. What happens when ground water is used at a faster rate than it is replaced? SUBSIDENCE

16. Groundwater, cont’d • Aquifer- an underground formation that contains groundwater • Recharge zone – an area of the Earth’s surface from which water percolates down into an aquifer • environmentally sensitive b/c any pollution in this zone can enter the aquifer. • Size of recharge zone affected by permeability of the surface above the aquifer. • Well – a hole that is dug or drilled to reach groundwater.

18. Water Pollutionsec.3 ch.11 • Compare point and non-point pollution and nonpoint-source pollution • Classify water pollutants by five types • Explain why groundwater pollution is difficult to clean up • Describe the major sources of ocean pollution • Describe laws designed toimprove water quality in the United States.

19. 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. Two types • Point-source pollution – discharged from a single source. Ex.’s leaking septic-tanks unlined landfills water discharged by industries leaking underground storage tanks

20. Water Pollution, cont’d 2. Non-point source pollution – comes from many different sources that are often difficult to identify. Ex.’s • a river being polluted by runoff from any of the land in its watershed. • precipitation containing air pollutants • Water runoff from city and suburban streets • Fertilizers, pesticides, herbicides from lawns, golf courses, and residential lawns

21. Non-point source pollution

22. Water Pollutants • Waste water – contains waste from homes or industry. Cleaned by a wastewater treatment plant, filtered, and treated to make the water clean enough to return to a river of lake. • Sewage sludge – the solid material that remains after water treatment. Contains dangerous concentrations of toxic chemicals = hazardous waste. * very costly to cities and towns to dispose of * many communities seek new uses for this waste – like fertilizer

23. Principle Water Pollutants, cont’d Eutrophication – the natural process where organic matter builds up in a body of water, decay, and decompose, using up oxygen. Artificial eutrophication– caused by humans when fertilizer from farms, lawns, gardens, and other runoff from phosphates in detergents

24. Effects of Artificial Eutrophication • Algal blooms – excessive growth of algae due to phosphorus. • As the algae die and decompose , most of the oxygen is used and fish and other organisms suffocate to death.

25. Red-Tide –type of algae that produce red pigment and toxins

26. Thermal Pollution – occurs when the temperature of a a body of water increases, causing death of fish and other organisms • Caused by power plants and industries using water to cool systems, then discharging the water into a lake or river.

27. Groundwater Pollution – polluted surface water percolates down from Earth’s surface • Pesticides, herbicides, chemical fertilizers, and petroleum products. • Mostly from millions of underground storage tanks in the United States. • Groundwater pollution is one of the most challenging environmental problems that society faces.

29. Ocean Pollution • Pollutants dumped directly into oceans • 85% of ocean pollution comes from activities on land ( oil, toxic wastes, medical wastes) • Oil spills – account for only about 5% of the oil pollution in oceans. • 200-300 million gallons of oil enter the ocean from non-point sources on land.

30. Biomagnification • Buildup of pollutants at higher levels of the food chain. • Has alarming consequences for organisms at the top of the food chain. Ex. DDT in the early 1900’s

32. Federal Laws Designed to Improve Water Quality in the United States( pg.313) 1972 Clean Water Act 1972 Marine Protection Research, and Sanctuaries Act 1975 Safe Drinking Water Act 1980 Comprehensive Environmental Response Compensation Liability Act 1987 Water Quality Act 1990 Oil Pollution Act

33. The Clean Water Act