2. Water is fundamental to life A human baby is 75% water Water is used in chemical reactions Water moves up 300’ tall plants Water regulates temperature

3. What do you know about water chemistry? The ends are charged Its POLAR

4. 2. Capillary action: cohesion=surface tension adhesion= sticks to surface 5. Universal Solvent 3. Expands when frozen 1. Polar molecule: attracts other polar molecules 4. High specific heat Water’s unique properties

5. Geographic factors determine precipitation amounts I.Proximity to water source II.Global Wind patterns III.Topography : Mountains create rain- shadowsrain- shadows Dew Point= Temperature where the condensation exceeds evaporation and condensation occurs Mass of water vapor divided by mass of dry air = absolute humidity absolute humidity to maximum potential humidity in air = relative humidity

6. Major Water Compartments

7. How much water is available for our use? Of the 2.5% freshwater 1.7% ice: unavailabe 0.7% surface water Marine water = 97.5% Fresh water = 2.5%

8. How can you define where a watershed is located? a. Topography b. Where the water collects c. Where the water exits

9. The Oceans are a Major Water Compartment The oceans hold 97% of all liquid water on the earth. 90% of the earth’s biomass is found in the oceans. The oceans play a major role in moderating earth’s climate. Ocean currents moderate the climate by redistributing warm and cold water around the earth like a global ocean conveyor belt.

10. Global Ocean Conveyor System

11. Community’s water source Geographical vs. Political Boundaries How many bathtubs did it rain last night?

12. What controls how much water flows in a stream (watershed)? Precipitation: Infiltration: Shallow: moves to stream Deep: moves to groundwater Soil characteristics Soil saturation Land cover Slope

13. What are the effects of increased run- off to a stream? Sediment load Reduced light Changes substrate Increased PM Increased velocity Erodes river banks Increased nutrients Eutrophication Less available water Conflicts over water use

14. Reduce runoff Buffer zones Rain gardens Swales Pervious paver

15. Personal water use Global average : 1,385 m 3 / yr; A person needs 2.5 qts per day (from all sources) Water trivia facts How much does it take to produce one ton of steel? 62,600 gallons How much water does it take to process one chicken? 11.6 gallons Demand for water is specific, availability is not

17. Consumptive or Withdrawal? Consumptive water, according to the text is water that is made unavailable for human use due to evaporation, tied up in plants or animals, chemical changes,

18. Renewable water is the total of readily available surface and groundwater minus evaporation. Water scarcity = demand exceeds available Water Stress = Water scarcity + increased competition for demand.

19. Water withdrawals

21. Conflicts in water value Agricultural demand Aral sea: CA Lake Owen dried up by 1924 Lake Mono lost 41% of its volume between 1941 & 1982 Today the San Joaquin valley is in jeopardy

22. Land subsidence The San Joaquin Delta, produces 25 % of the nation’s table food on only 1 % of the country’s farmland The maximum subsidence, near Mendota, was more than 28 feet. Subsidence has slowed or reversed because surface water is being pumped in

24. Env. factors affect

25. Porosity: volume of all of the open spaces

26. Permeability: Connectivity of pores & pore size

28. Groundwater Stores Large Water Resources Aquifers - porous layers of sand, gravel, or rock lying below the water table Artesian - Pressurized aquifer intersects the surface (water flows without pumping). Recharge zones - area where water infiltrates into an aquifer Recharge rate is often very slow. Presently, groundwater is being removed faster than it can be replenished in many areas.

29. Ground Water Compartments  Ground water is the second largest reservoir of fresh water  Infiltration - process of water percolating through the soil and into fractures and permeable rocks Zone of aeration - upper soil layers that hold both air and water Zone of saturation - lower soil layers where all spaces are filled with water Water table - top of zone of saturation