1. Chapter 9

2. Water as a Resource http://snr-1349.unl.edu/navigation/waterdistribution.aspx

3. Groundwater Exists in aquifers (permeable layers of rock and sediment) a. confined aquifer b. unconfined aquifer Water table a. uppermost level where water still saturates rock or soil b. “surface of the groundwater” Groundwater recharge

4. Sources of aquifers a. springs - source of freshwater - water naturally rises to the ground surface b. artesian wells - drilling in confined aquifer - releases pressure on the water http://www.ec.gc.ca/eau-water/default.asp?lang=En&n=300688DC-1

5. Problems with water from unconfined aquifer - recharge very quickly - contamination with chemicals Largest aquifer - Ogalla in the Great Plains - lots of water is being withdrawn (problem!)

6. Cone of Depression a. an area where there is no longer any ground water b. water table drops too low c. comprises water quality

7. Saltwater intrusion a. drilling wells along coastline b. rapid pumping lowering water table c. adjacent saltwater infiltrates in

8. Surface Water Freshwater that exists above ground - streams, rivers, ponds, lakes, and wetlands Rivers a. 3 largest - Amazon in SA - Congo in Africa - Yangtze in China

9. b. land surrounding rivers is typically fertile c. floodwaters deposit nutrient-rich sediment onto the floodplain Lakes a. classified by level of primary productivity b. oligotrophic v. eutrophic Wetlands a. control flooding

10. Atmospheric Water Drought a. long-term effects on soil Flooding a. water input exceeds the ability of an area to absorb the water b. areas affected by drought-impermeable surfaces- flood

11. Altering the Availability of Water Levees a. enlarged bank built up on each side of the river b. Mississippi River – largest system of levees c. major challenges - floodwater no longer add fertility to floodplain - sediments will deposit further down where river meets ocean - cause even worse flooding downstream - can collapse

12. Dikes a. built to prevent ocean waters from flooding adjacent land b. common in Europe – farmland below sea level

13. Dams a. barrier that runs across the river or stream to control the flow of water b. reservoir c. used to generate electricity d. world’s largest – Three Gorges Dam in China e. environmental problems - interruption of natural flow of water (fish ladders)

14. Aqueducts a. canals/ditches used to carry water from one place to another b. concrete canals and pressurized steel pipes c. In the US: NYC and LA d. ensures clean water, but disturbs habitats e. diversion project - Soviet Union diverted two rivers that fed into the Aral Sea

15. Desalination (desalinization) a. removing salt from sea water b. 2 common techniques 1. distillation 2. reverse osmosis - leaves behind a brine (high salt concentration) http://bcs.whfreeman.com/friedlandapes/#668210__690864__

16. Water Use Freshwater a. 70% - agriculture 30% - industrial and household http://www.data360.org/dsg.aspx?Data_Set_Group_Id=757

17. Agriculture a. largest use of water b. US: 1/3 of freshwater is used for irrigation 1. furrow – 65% efficient 2. flood – 70-80% efficient 3. spray – 75-95% efficient 4. drip – over 95% efficient (reduces weed growth)

18. c. hydroponic agriculture 1. alternative to traditional agriculture 2. crops under greenhouse conditions 3. uses 95% less water than traditional irrigation http://blog.syracuse.com/cny/2011/01/hydroponic_farming_satisifes_central_new_yorks_craving_for_local_greens_in_midwinter.ht ml

19. Industry a. in US, ½ water goes towards electricity b. cools machinery (steam) c. refines metals d. used to make paper

20. Household a. in US, 10% water used in homes b. Indoor use 1. flushing toilets (41%), bathing (33%), laundry (21%), and cooking/drinking (5%) c. Outdoor use 1. watering lawns, washing cars, etc. d. drinking water

21. Water Conservation A NECESSITY! Improved efficiencies in toilets and shower heads Plant vegetation that’s appropriate for your climate a. Las Vegas, Nevada