What is the hydrologic cycle? • The water cycle • Precipitation • Evaporation • transpiration
What is ground water? • Groundwater is water that is below the water table (level where the ground is saturated). • Aquifer= zone where groundwater can be obtained from
What is surface water? • Surface water is water found above the water table/at the surface of the earth.
Why do we have groundwater use problems? • ½ the people in the US use ground water as a primary source of drinking water, sometimes at a rate of overdraft. • Amount of water withdrawn is greater than inflow into the well.
What is the difference between in-stream and off stream use? • Off stream use = water removed from its source for use • Some water is returned to the source (i.e. industrial cooling water) • Consumptive use = water taken in (not returned to source) by humans, plants or animals • In stream use = the use of water NOT removed from its source/ in rivers, dams, fish and wildlife habitats…etc.
How can we conserve water through agricultural use? • Agriculture accounts for 65% of total freshwater with-drawls of water between 1950-2005. • (in reading)
How can we reduce our public supply and domestic use (at home)? • Think ecological footprint (in reading)
What is water pollution? • The degradation of water quality, so that it harms living organisms or is not fit for human use.
What is Biochemical oxygen demand? • The amount of oxygen required for biochemical decomposition processes. • When BOD increases, then dissolved oxygen decreases
What is water borne disease and how is it most commonly detected? • Illness caused by bacteria or viruses in the water, whose symptom vary from a stomach ache to death.
How do we monitor disease carrying organisms? • Fecal coliform
What nutrients most commonly cause water pollution? • Nitrogen and phosphorus
What is Eutrophication? • The process by which a body of water develops a high concentration of nutrients, such as nitrogen and phosphorus (in the forms of nitrates and phosphates).
What are the effects of Eutrophication? • 1. Increased aquatic plant and algae growth • 2. Blockage of sunlight by algae • 3. plants and good bacteria die, and start to decompose • 4. Decomposition increases BOD as the number of decomposers increase • 5. Dissolved oxygen decreases • 6. Fish die/ecosystem starts falling apart
What is cultural Eutrophication? • Eutrophication accelerated by humans • Urban = sewage • Rural = agricultural run off
What are some causes of water pollution? • Oil • Sediment • Acid mine drainage • Agricultural Run off