Chapter 9 Water Resources

Dams and Salmon on the Klamath River Klamath River – runs for 250 miles Historically, salmon life on the river occurred in multiple stages In last 100 yrs: Salmon population has been greatly reduced by… 1997 – the coho salmon became endangered species  protected 2002 – migrating salmon experienced massive die-off 2009 – agreement by ~30 interest groups (signed 2010)

Usable Water is Rare

Groundwater Aquifers- small spaces found within permeable layers of rock and sediment where water is found Unconfined aquifers Confined aquifers

Groundwater Confined vs. unconfined aquifers differences: Age of water in aquifer varies/rate at which it recharges Large scale water use

Groundwater Water table- the uppermost level at which the water in an area fully saturates the rock or soil Recharge- the input process of water percolating into an aquifer Springs- water from an aquifer that naturally percolates up to the surface Traditional wells vs artesian wells

Groundwater When water is overused  water table drops Cone of depression- an area where there is no longer any groundwater

Groundwater Some coastal regions have abundance of fresh water underground Saltwater intrusion- when the pumping of fresh water out of a well is faster than the recharge causes salt water to infiltrate the aquifer

Surface Water Includes: Streams, rivers, ponds, lakes and wetlands Early civilizations settled along rivers Floodplains – land adjacent to river that may flood when heavy rainfall or spring snowmelt occurs Figure 9.7

Surface Water Formation of a lake: Productivity in a lake: Tectonic activity Movement of glaciers Productivity in a lake: Oligotrophic Mesotrophic Eutrophic

Atmospheric Water Important to global water distribution Droughts – prolonged time without predictable water Can have negative effects – destroy crops, kill cattle = many people go hungry Human activities Flooding – when water inputs exceed the ability of an area to absorb the water Human impact

Changing Water Availability

Altering the Availability of Water Ways to try to reduce impact of flooding: Levees- an enlarged bank built up on each side of the river Challenges Dikes- similar to a levee but built to prevent ocean waters from flooding adjacent land

Altering the Availability of Water Dams- a barrier that runs across a river or stream to control the flow of water Benefits: human consumption, generation of electricity, flood control, recreation Costs: environmental, societal, and financial Reservoir- the area where water is stored behind the dam

Altering the Availability of Water Fish ladders- a set of stairs with water flowing over them that have been added to some dams to help migrating fish such as salmon get upstream

Altering the Availability of Water Aqueducts- canals or ditches used to carry water from one location to another Benefits: Downsides:

Altering the Availability of Water Desalination- removing the salt from salt water to obtain fresh water From ocean or salty inland lakes 2 common technologies: You will learn more about from your classmates

Water in Agriculture, Industry and the Home

Agriculture, Industry, and Household Needs Figure 9.16 – Per capita water use per day Total used for agriculture, industry and household Agriculture- the largest user of water around the world

Agriculture, Industry and Household Needs Irrigation techniques- Furrow irrigation Flood irrigation Spray irrigation Drip irrigation

Agriculture, Industry and Household Needs Hydroponic agriculture- crops grown in fertilized water and no soil Greenhouse conditions Alternative to traditional irrigation Growing in popularity Cost to consumer is higher

Agriculture, Industry and Household Needs Industry- the second largest user of water worldwide Includes: Hydroelectric dams Thermoelectric power plants Refining of metals and paper

Agriculture, Industry and Household Needs Households- the third largest user of water worldwide LDC vs. HDC Includes both indoor and outdoor water use

The Future of Water Availability Water ownership- people can have rights to water use, but they do not own the water Water conservation- using techniques such as more efficient water fixtures, faucets and washing machines