1. Chapter 11 - Water

2. Water
Is a major limiting factor on populations because organisms must have to survive.
Is considered a renewable resource because water is replaced by the water cycle.
Condensation
Precipitation
Evaporation

4. Water Resources 97 % of Earth’s water (hydrosphere) is Salt Water
water with 3.5% salt concentration or greater is considered salt water

5. Water Resources (cont.)
3 % of the Hydrosphere is Fresh Water
77% of fresh water (most of it) is trapped in polar ice caps

6. Water Resources (cont.)
22% of Fresh Water is Ground Water – water that percolates through the soil and is trapped.
Aquifers – underground areas of porous rock that hold water.

7. Water Resources (cont.)
1% of fresh water is Surface Water:
Most large cities depend on surface water for residential and industrial needs.
For Example:
Lakes
Streams
Ponds

8. Renewal of Surface/Ground Water
A watershed is the area drained by a river.
Some surface water seeps into aquifers and becomes groundwater.
Major Watersheds

9. Renewal of Surface/Ground Water (cont.)
Groundwater (in aquifers) is replenished by precipitation in the recharge zone.
development can lead to obstruction of recharge zone.

10. Subsidence

11. Water Usage 67 % for Agriculture 19 % for Industry
Worldwide water usage breaks down to :
67 % for Agriculture
19 % for Industry
14 % for Residential Usage
these are average usage worldwide, but it can vary between areas

12. There are many types of irrigation.
Water Usage (cont.)
1. Agriculture
There are many types of irrigation.
Furrow
Overhead
Flood

13. Water Usage (cont.) 2. Industrial
used to generate power, dispose of waste, and manufacture of goods.

14. Water Usage (cont.) 3. Residential For Personal hygiene For cooking
For Drinking

15. Water Usage (cont.) 3. Residential (cont.)
water usage varies from one area to another
USA = greatest usage = 300L (80 gallons) per day
India = 41L per day
water must be treated to be considered potable
1st Filtration 4. Chlorination
Coagulation 5. Aeration
Second Filtration 6. Additional Treatment (Fluorine)

17. Water Management Projects
1. Aqueducts - built to move water around
Ancient aqueducts still standing
Modern structures are also in use

18. Water Management Projects (cont.)
2. Water Diversion Projects – diversion of river or lake water for use elsewhere.
Can cause huge problems for areas like Mono Lake where a decrease of replenishing water leads to increased salinity level of lake. Bad for organisms!

19. Water Management Projects (cont.)
3. Dams
Creates reservoirs for recreation, and is good for flood control, and the production of hydroelectricity
Can be bad for the ecosystem and cause disputes with neighboring states or countries.

20. Water Conservation
Is an inexpensive way to maintain fresh water resources.
Agriculture
Drip Irrigation is a method of delivering water to crops that can save huge amounts of water.
Israel water usage cut by 75% by drip irrigation.

21. Water Conservation Industry
Recycling of wastewater and cooling water from manufacture of goods.

22. Water Conservation Residential
Use xeriscaping (planting of native plants) in lawns to decrease a need to water.
Installing low flow shower heads and toilets as well as just turning off the water when you brush!

23. Desalination Processes
The process by which salts are removed from ocean water making it potable.
1. Distillation - boil and condense water leaving behind impurities. 2
1. Heat salt water until turns to steam
2. Steam travels down tube where it cools and condenses. 1
3. Water (now free of salts and impurities) is collected and can be used. 3

24. Desalination Processes (cont.)
2. Reverse Osmosis
achieved by forcing water through a membrane (filter) that removes salts and impurities.

25. Desalination Processes (cont.)
3. Freezing
only the fresh water will freeze. Salts are trapped in brine slush that can be taken away.

26. Transporting Water
Towing icebergs has been suggested, but has many risks and complications involved.
Floating giant bags of water from one area to another has also been suggested, but this technique has many problems associated with it as well.

27. Pollution of Water
The introduction of chemical, physical, or biological agents into a water source.
Two Major Classifications :
1. Point-Source Pollution – pollution from a single (usually easily identifiable) source
Leak from underground gas tank
From Industry, Mines, and Buried Gas or Septic Tanks

28. Pollution of Water 96 % of H2O pollution is non-point source pollution
2. Non-Point Source Pollution - pollution from many different (often hard to identify) sources.
96 % of H2O pollution is non-point source pollution

29. Types of Pollutants and Sources
Pathogens – cause disease – parasitic worms, virus, bacteria.
Organic Matter – feces, animal remains
Chemicals – both organic and inorganic
Heavy Metals – mercury, arsenic
Physical agents – heat, solid material (trash)

30. Consequences of Pollution
Oxygen Depletion in Water
Causing death of organisms
Artificial Eutrophication – caused by nutrients (phosphorous and nitrogen) from runoff materials.
2. Thermal Pollution - disrupts ecosystems and kills
organisms.

31. Biomagnification
The accumulation of pollutants in higher level organisms.

32. Ground H2O Pollution Comes from many sources
Underground storage tanks, and unlined landfills. Modern landfills are lined.
Clean-up very difficult

33. Ocean Pollution Most comes from activities on land.
Some from polluted rivers dumping into the sea
Occurs mostly near coasts having a devastating effect on wetlands and estuaries that actually help filter out pollutants.
Oil spills only account for 5% (road oil is far greater percentage)

34. Water Quality Laws 1972 – Clean Water Act – first major legislation
1972 – Marine Protection, Research, and Sanctuaries Act
1975 – Safe Drinking Water Act
1980 – Superfund Act – held polluters accountable for cleanup
1987 – Water Quality Act
1990 – Oil Pollution Act

35. The End