tailieunhanh - GS 106 Notes - Water Pollution

The guiding principles for water resources management (see section ) should be reflected in the long-term strategy. For example, management at the lowest appropriate level should be pursued through the identification of the lowest appropriate level for all identified key functions, irrespective of the present level of management. For some functions, the lowest appropriate level is a local authority or unit, while for other functions it is a central authority (. Case Study I, India). The case study for China (Case Study II), however, provides an example of the opposite approach, . centralised control of pollution. Table gives an. | GS 106 Notes - Water Pollution I. Water as a Natural Resource A. Near-Surface Components of Hydrologic Cycle 1. Oceans 2. Rivers 3. Groundwater B. Water as a Resource Important Uses 1. Required for Life Plants Animals 2. Human Consumption 3. Irrigation Agricultural Production 4. Industrial Processing 5. Domestic Wastewater Management sewage C. Water Use in the United States 1. Basic Budget approximate a. . Rainfall 4200 billion gal day input b. Evapotranspiration 2750 billion gal day output c. Streamflow Groundwater 1400 billion gal day 2. Human Consumption of Water a. average human needs 1 gal day for internal consumption b. . daily consumption 400 billion gallons per day c. Actual Use 1800 gal person day 1 consumption cooking washing industrial agricultural 3. Water Resource Problems a. Water use does not match population needs b. water pollution reduces effective amount available for use 4. Water Supplies in . a. Surface Water vs. Groundwater 1 surface water important in humid regions 2 groundwater important in arid regions a largest reservoir of unfrozen fresh water b. Seasonal Variation in Water supply 1 droughts 2 seasonal rainfall changes c. Dams and Water Reservoirs d. Highest Water Use 1 Urban Areas 2 SW . a irrigation b high population growth c arid conditions 1 II. Water Pollution Issues A. Introduction 1. water is a good solvent commonly associated with dissolved chemical constituents 2. pollution - contamination of water with unwanted or hazardous chemical constituents 3. common pollution sources a. industry b. agriculture c. domestic sewage B. Natural Geochemical Cycles 1. water dissolving elemental constituents from rock and sediment material 2. Commonly dissolved weathering products from rock material a. calcium iron sulfer sodium chloride magnesium C. Residence Time - duration with which water resides in Earth reservoir systems 1. residence time opportunity for dissolution and addition of dissolved chemical constituents 2. residence .