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CGEO 702 TECHNOLOGY & CONTEMPORARY ENVIRONMENTS Lecture 7 [Water Resources] Dr Abednego Aryee Department of Geography Ryerson University Freshwater systems Water may seem abundant, but drinkable water is rare Freshwater = relatively pure, with few dissolved salts Only 2.5% of Earth’s water is fresh, most is tied up in glaciers and ice caps 11-* FIGURE 11.1 GLOBAL PERSPECTIVES ON WATER What is the benefit of the hydrological cycle? Sources of water supply Groundwater and stream - streams - aquifers Precipitation and run-off Wetlands (services and functions) A typical lake 11-* MAJOR RIVERS IN THE WORLD OGALLALA AQUIFER IN THE USA It is the largest aquifer In North America. Extends 174, 000 sq. miles under 8 states. It contains 3 billion ac-fit in Texas. In Texas, more ground water is produced from the Ogallala than all other aquifers combined. PHYSICAL CONTAMINATION Sediment: - Sediment load into lakes rivers. Heat: - Thermal heating from power plants. SEDIMENTS WATER-BORNE DISEASES BIOLOGICAL CONTAMINATIONS - Fecal Coliform Bacteria - Outbreak of Walkerton, Ontario - Outbreak of Cryptosporidium in Milawaukee same case in Kitchener waterloo and - Cultural eutrophication in lake Winnipeg Eutrophication ACCIDENTS & CARELESS CONTAMINATION CHEMICAL CONTAMINATIONS - Oil spills eg. Exxon Valdez Oil Spill in Prince William Sound in alaska - Jessica: Galapagos Island oil spill - Acid mine drainage in British Columbia, Ontario and Quebec etc. Exxon Valdez Oil Spill at Prince William Sound (Alaska) Exxon Valdez Oil Spill at Prince William Sound (Alaska) Freshwater pollution sources 11-* FIGURE 11.21 Point Source Non-point sources TREATMENT OF CONTAMINATED WATER Elimination of the source Monitoring Remediation Disposal of nuclear waste Septic tank disposal system Wastewater treatment plants Chlorine treatment Managing Water Resources Input Approach - This entails an increase in water supply via new water sources Output Approach: - Increasing efficiency of water usage - Controlling contamination of existing sources Trans-boundary Basins Between US and Canada Source: Fischhendler I. & Feitelson E, 2004 The Aral Sea Once the fourth-largest lake on Earth lost over 80% of its volume in 45 years from diversion Consequences Lost 60,000 fishing jobs Pesticide-laden dust from the lake bed is blown into the air The cotton cannot bring back the region’s economy 11-* FIGURE 11.13 WATER DEMAND AND SUPPLY Agriculture Domestic use Industrial & manufacturing use Dams, canals and channelization A typical dam
