Environmental Sciences: Water Unit Hydrologic Cycle and Human Water Use.

1. Environmental Sciences: Water Unit Hydrologic Cycle and Human Water Use.

2. Contents of this power point Basic Water Knowledge and Review • Slides 2 – 20 How do Humans affect Water Distribution? • Slides 21 – 29 Chapter 11 Sustaining Aquatic Biomes • Slides 30 – 64 • End here for Quiz

3. Special Properties of Water: • Exists in three phases:solid, liquid, gas. • Polar molecule due to unequal sharing of electrons in the H2O molecule. • High Surface tension & great solvent. Makes it adhesive & cohesive. • High heat capacity due to hydrogen bonding.

4. The Water Cycle is Nature’s Way to Purify Water by Evaporation/ Filtration. • Human have managed to pollute or compromise the function of the loop. • We are running out of water in terms of quantity and quality. • Water conservation and stewardship are imperative actions.

5. Earth’s Water

6. Fresh Water Properties: • Makes up less than 3% of all water on Earth. This includes the Polar Ice caps and glaciers. Less than 1% is ready to treat and use. • Has a salt content of less than 0.01% • Is constantly being recycled naturally. • Makes up > 70% of the human body. • Is necessary for all life on Earth.

7. Water Cycle Processes • Evaporation: water molecules move from liquid to gaseous state; e.g. steam • Condensation: water molecules move from gaseous to liquid or frozen state; e.g. water droplets on cold beverage container • Purification: occurs as a result of evaporation and condensation; impurities are left behind

8. Condensation

9. Precipitation • Adiabatic cooling: warm air rises, expands and cools • 100% relative humidity + cooling = clouds • Increasing condensation = water droplets

10. The Water Cycle

11. Water Cycle Filters Evaporative-transpiration Loop F D G Surface Runoff Loop B E Ground Water Loop A C

14. Human Impacts on the Water Cycle • Changing the earth’s surface • Pollution • Withdrawal for use

15. ReviewGlobal Precipitation and Weather • Global precipitation distribution depends on patterns of rising and falling air currents • Two main factors: • global convection currents • rain shadow effect

16. Review: What ControlsWeather? • Atmospheric Pressure and Solar Energy! • Low Pressure= Storms / rain • High Pressure = Fair skies

17. Review: Major World Climates

18. Review: World Precipitation Levels

19. Review: What affects Climate? Global Wind Mechanisms that give rise to weather patterns.

20. Review: Rain Shadow Effect

21. How do humans change the Earth’s surface? 1. 2.

22. Changing Earth’s Surface Through Urbanization • Decreased infiltration • Increased runoff

23. How do humans pollute the water? 1. 2. 3. 4.

24. Water Pollution

25. How do humans use water? 1. Agricultural uses 2. Domestic Uses 3. Industrial uses

26. Water Use

27. AgricultureWater Use:

28. Consequences of Overdrawing Water Supplies • Surface waters: • shortages • ecological effects

29. Water Use

30. Chapter 11: Sustaining Aquatic Environments • Be sure to read Chapter 11, noting the Major concepts in each sections. • This power point does not follow the order in the text book, but highlights all the major facts and concepts you need to know.

31. Why are Wetlands Vanishing? • Urbanization: filling-in, covered over • Draining: disease control(mosquito-born e.g. malaria) • Extraction of minerals, oil & gas

32. Ecological Services of Wetlands: Hydrological Cycle • Purify waters: filtering toxins & waste • Control floods: absorb storm water& overflow • Protect shorelines: against erosion • Recharge groundwater & aquifers

33. Ecological Services of Wetlands: Chemical Cycles • Nitrogen cycle • Sulfur cycle • Carbon cycle

34. Ecological Services of Wetlands: Increase Biodiversity • Terrestrial ecosystems: • Aquatic ecosystems

35. Wetland Services - Economic • Pelt and skin harvesting (alligator) • Waterfowl hunting • Sport and commercial fishing • Timber harvesting (hardwood and cypress swamps) • Energy source • Food source • Recreation

36. Wetland Services - Intrinsic • Bird watching and wildlife photography • Recreation (hiking, boating) • Biological laboratory for students of all ages

37. Consequences of Overdrawing • Groundwater: • Falling water tables • Diminishing surface waters (wetlands) • Land subsidence • Saltwater intrusion

38. Aquifer Exploitation The Ogallala Aquifer is the world’s largest and is used extensively to make this area of the USA productive.

39. Irrigation on a Large Scale

40. Irrigation by Drip Method Saves Water

41. Sinkholes: YIKES!

42. Saltwater Anyone?

43. Using Less Water • Irrigation • Surge flow • Drip irrigation $$ • Municipal uses • Incentives • regulations limiting water use • Gray water

44. Must know Figures in CH 11 • Fig. 11-12 Managing Fisheries • Fig. 11-16 Ecological Services of Rivers • Fig 8-14 Natural Capital of Fresh Water Systems

45. How do we Protect Aquatic Habitats? • Regulations, laws & enforcement • Economic incentives • Preservation & restoration

46. How do we protect & preserve Wetlands? • Zoning laws – control development • Federal Permits to dredge • “Mitigation Banking”

47. Mitigation Banking (a last resort!?) • Requires that new wetlands be constructed before existing is destroyed • Nat’l Acad of Science -> can’t replace & expect it to do as well as the natural • Don’t actually meet the goals • Not adequately monitored

48. Restoration of a wetland: Florida Everglades:CERP (Comprehensive Everglades Restor. Plan) Why needed? Drying up & polluted Cause: population growth therefore ^ need • Diversion of input (^salt; ^ temp) • Increased Nutrients (run-off: ^algal blooms, dec. O2 & ^CO2

49. CERP’s Idea Good or Bad? • Restore flow • Remove canals & levees that block flow • Buy land (sugar cane farms) & flood it • Build 18 Reservoirs for storage • Build new canals What is wrong with this picture?

50. Problems with CERP • Resistance from farmers – political pressure & delays • Big budget grows with delays • Will it really work?