12- 1

1. 12-1

2. Housekeeping Items for Day 11 • Relevant to last class see Janice Benyus on biomimickry: http://www.ted.com/talks/janine_benyus_shares_nature_s_designs.html. On the Great Bear, see also: https://vimeo.com/33234007. • I will hand back the exams today, but we won’t have time to go through them. If you have questions, come to my office hours on Wednesday as I have a class right after this one. • I would like to bring another book to your attention: How Bad Are Bananas? The Carbon Footprint of Everything by Mike Berners-Lee (Vancouver: Greystone Books, 2011). • The Geography Department is hosting a session on what you need to know about grad school with past graduates and faculty members sharing their experience this Wednesday in Room 217 at 10:30. • Just a reminder that, in view of our being behind in the schedule, we will skip Chapters 10 and 11, but please read on your own.

3. Upon successfully completing this chapter, you will be able to • Explain the importance of water and the hydrologic cycle to ecosystems, human health, and economic pursuits • Delineate the distribution of fresh water on Earth • Describe major types of freshwater ecosystems • Discuss how we use water and alter freshwater systems • Assess problems of water supply and propose solutions to address depletion of fresh water • Assess problems of water quality and propose solutions to address water pollution • Explain how waste water is treated

4. Canadians fear we will place our sovereignty at risk is we allow large-scale diversions of fresh water • Once they start, they will be impossible to stop • Some view water as a marketable commodity, others say we should not consider exporting it to those have mismanaged theirs. • Canada’s fresh water is protected as each province and territory prohibits bulk water exports • “The wars of the twenty-first century will be fought over water.” • – World Water Commission Chairman Ismail Serageldin

5. Freshwater Systems 12-5

6. 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 (what’s usable is about .25%)

7. Rivers and streams wind through landscapes Source: http://www.bccf.com/steelhead/focus7.htm • Water from rain, snowmelt, or springs forms streams, creeks, or brooks • These merge into rivers, and eventually reaches the ocean • Tributary = a smaller river slowing into a larger one • Drainage basin or watershed = the area of land drained by a river and its tributaries

8. Rivers and streams wind through landscapes (cont’d) • If there is a large bend in the river, the force of the water cuts through the land • Oxbow = an extreme bend in a river • Oxbow lake = the bend is cut off and remains as an isolated, U-shaped body of water

9. Rivers and streams wind through landscapes (cont’d) Source: 1bp.blogspot.com • Floodplain = areas nearest to the river’s course that are flooded periodically • Frequent deposition of silt makes floodplain soils fertile • Riparian = riverside areas that are productive and species-rich • Water of rivers and streams hosts diverse ecological communities

10. Wetlands include marshes, swamps, and bogs • Wetlands = systems that combine elements of freshwater and dry land • Freshwater marshes = shallow water allows plants to grow above the water’s surface (e.g. Buttertubs Marsh) • Swamps = shallow water that occurs in forested areas • Can be created by beavers (e.g. W. Linley Valley) • Bogs = ponds covered in thick floating mats of vegetation • A stage in aquatic succession

11. Wetlands include marshes, swamps, and bogs (cont’d) • Wetlands are extremely valuable for wildlife • They slow runoff • Reduce flooding • Recharge aquifers • Filter pollutants • People have drained wetlands, mostly for agriculture • Manitoba has lost more than half of its “pothole” wetlands

12. Lakes and ponds are ecologically diverse systems • Lakes and ponds are bodies of open, standing water • Littoral zone = region ringing the edge of a water body • Benthic zone = extends along the entire bottom of the water body • Home to many invertebrates • Limnetic zone = open portions of the lake or pond where the sunlight penetrates the shallow waters • Profundal zone = water that sunlight does not reach • Supports fewer animals because there is less oxygen

14. Lakes and ponds are ecologically diverse systems (cont’d) • Oligotrophic lakes and ponds = have low nutrient and high oxygen conditions • Eutrophic lakes and ponds = have high nutrient and low oxygen conditions • Eventually, water bodies fill completely in through the process of succession • Inland seas = large lakes that hold so much water, their biota is adapted to open water

15. Groundwater plays key roles in the hydrologic cycle • Groundwater = precipitation that does not evaporate, flow immediately into waterways, or get taken up by organisms • Aquifers = Porous sponge-like formations of rock, sand, or gravel that hold groundwater • Zone of aeration = spaces are partially filled with water • Zone of saturation = spaces are completely filled with water • Water table = boundary between the two zones • Aquifer recharge zone = any area where water infiltrates Earth’s surface and reaches aquifers

16. A typical aquifer

17. Groundwater plays key roles in the hydrologic cycle (cont’d) • Confined or artesian = water-bearing, porous rocks are trapped between layers of less permeable substrate (i.e., clay) • Is under a lot of pressure • Unconfined aquifer = no upper layer to confine it • Readily recharged by surface water • Groundwater becomes surface water through springs or human-drilled wells • Groundwater may be ancient: the average age is 1,400 years

18. Water is unequally distributed across Earth’s surface • Many areas with high population density are water- poor and face serious water shortages

19. Climate change will cause water problems and shortages • Climate change will affect the hydrologic cycle: • Shift northward in mid-latitude rain belt • Earlier snowmelt and spring runoff • More evapotranspiration • Drier summers in the interior continental region • Additional impacts: • Warmer rivers (impacting fish) • Lower water levels in Great Lakes • Higher ocean water levels

20. How We Use Water 12-20

21. How we use water • We have achieved impressive engineering accomplishments to harness freshwater sources • 60% of the world’s largest 227 rivers have been strongly or moderately affected • Dams, canals, and diversions • Consumption of water in most of the world is unsustainable • We are depleting many sources of surface water and groundwater • One-third of the world’s people are already affected by water scarcity Source: Bing

22. Water supplies houses, agriculture, and industry

23. Water supplies houses, agriculture, and industry (cont’d) • Consumptive use = water is removed from an aquifer or surface water body, and is not returned • Non-consumptive use = does not remove, or only temporarily removes, water from an aquifer or surface water • Electricity generation at hydroelectric dams • Cooling water for power planets or factories, or into which effluent is dumped

24. We have erected thousands of dams • Dam = any obstruction placed in a river or stream to block the flow of water so that water can be stored in a reservoir • To prevent floods, provide drinking water, allow irrigation, and generate electricity • 45,000 large dams have been erected in more than 140 nations • Only a few major rivers remain undammed • In remote regions of Canada, Alaska, and Russia

25. A typical dam

26. Benefits: Power generation Emission reduction Crop irrigation Drinking water Flood control Shipping New recreational opportunities Drawbacks: Habitat alteration Fisheries declines Population displacement Sediment capture Disruption of flooding Risk of failure Lost recreational opportunities Benefits and drawbacks of dams

27. China’s Three Gorges Dam is the world’s largest • 186 m high and 2 km wide, completed in 2006 • When filled it will be as long as Lake Superior • It has cost $25 billion to build, flooded 22 cities and the homes of 1.24 million people, submerged 10,000 year-old archaeological sites, productive farmlands, and wildlife habitat, and caused erosion below the dam • Some fear pollutants will also be trapped in the reservoir, making water undrinkable 12-27

28. Some dams are now being removed • Some people feel that the cost of dams outweighs their benefits • Rivers with dismantled dams • Have restored riparian ecosystems • Reestablished fisheries • Revived river recreation • In Canada only a few dams have been decommissioned but 500 dams have been removed in the U.S. (e.g., Sunbeam, Grangeville and Lewiston Dams in Idaho).

29. Dikes and levees are meant to control floods • Flooding is a normal, natural process • Floodwaters spread nutrient-rich sediments over large areas • Floods also do tremendous damage to property • Dikes and levees (long, raised mounds of earth) along the banks of rivers hold rising waters in channels • Levees can make floods worse by forcing water to stay in channels and overflow

30. We divert – and deplete – surface water to suit our needs • Diversion has drastically altered the river’s ecology • What water is left in the Colorado River after all the diversions comprises just a trickle into the Gulf of California and Mexico

31. We divert – and deplete – surface water to suit our needs (cont’d) 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

32. Inefficient irrigation wastes water • Today, 70% more water is withdrawn for irrigation than in 1960 • The amount of irrigated land has doubled • Crop yields can double • Only 45% of water is absorbed by crops via “flood and furrow” irrigation • Overirrigation leads to waterlogging, salinization, and lost farming income • Most national governments subsidize irrigation • Water mining = withdrawing water faster than it can be replenished

33. Areas where water use exceeds supply

34. Flood protection at what cost? weighingtheissues In May 2011, during record high-water levels on the Assiniboine River, the government of Manitoba deliberately breached a dike near Portage-la-Prairie, with the goal of releasing pressure in the Portage Reservoir and averting a much larger, uncontrolled flood. The controlled release put 150 homes and a considerable area of farmland at risk. In the end, the controlled breach worked, and no homes in the threatened area were significantly harmed.

35. Flood protection at what cost (cont’d)? weighingtheissues A similar situation occurred during the Red River Floodway of 1997, during which the Red River Floodway diverted floodwater to protect the city of Winnipeg, but perhaps at the cost of flooding in smaller communities such as St. Agathe. Both events caused significant stress for those in the path of diverted floodwaters. • If you were a decision maker in Manitoba, would you have reached the same decision? • Is it worthwhile to protect certain areas, even if it means risking others? • What might you do to compensate those who were at risk?

36. Wetlands have been drained for a variety of reasons • Promote settlement and farming • Seen as useless “swamps” • Ramsar (Convention on Wetlands of International Importance, especially as Waterfowl Habitat) Convention in 1971 • Global concern for wetland loss and degradation • Promotes local, regional, and national actions and international cooperation • 90% of original wetlands in southern Canada have been lost

37. We are depleting groundwater • Groundwater is easily depleted • Aquifers recharge slowly • 1/3 of world population relies on groundwater (20% of Canadian communities apart from individual households on wells) • As aquifers become depleted • Water tables drop • Salt water intrudes in coastal areas • Sinkholes = areas where ground gives way unexpectedly • Some cities (Venice, Mexico City) are slowly sinking • Wetlands dry up

38. Our thirst for bottled water seems unquenchable • Canadians’ use of bottled water only surpassed by U.S. • University-educated households were shown to be less likely to consume bottled water • Average capital use in 2003 was almost 50 L of bottled water • Most bottled water is nothing more than tap water, sometimes with additional filtering or other treatment • Canada’s Food and Drug Act does not require a manufacturer to obtain a licence to bottle water Source: http://www.mnn.com/food/healthy-eating/stories/5-reasons- not-to-drink-bottled-water 12-38

39. The price of a litre weighingtheissues • Do you drink bottled water? Why? • Do you think it is safer than municipal water? Do you prefer the taste? • What do you pay for a litre of bottled water? What do you pay for a litre of gas at the pump? • What do you think should be reflected in these prices? • What price do you think was paid for the water by the company that bottled it? • What about the source of the water you consume at home— is it groundwater and, if so, is its source adequately protected? • And what about the plastic waste that is generated?

40. Will we see a future of water wars? • Freshwater depletion leads to shortages, which can lead to conflict • 261 major rivers cross national borders • Water is a key element in hostilities among Israel, Palestinians, and neighboring countries • Many nations have cooperated with neighbors to resolve disputes • India, Pakistan, Bangladesh, Bhutan, and Nepal e.g., Asia: Amur River: People's Republic of China and Russia Brahmaputra River: India, Bangladesh and China Ganges River: India and Bangladesh Golok River: Malaysia and Thailand Indus River: India and Pakistan Kaladan River: India and Burma Mekong River: Burma and Laos Mekong River: Laos and Thailand Naf River: Bangladesh and Burma Pandaruan River: Malaysia and Brunei Darussalam Yalu River: North Korea and People's Republic of China Hirmand River: Iran and Afghanistan Fly River: Indonesia and Papua New Guinea

41. Solutions to Depletion of Fresh Water 12-41

42. Solutions can address supply or demand • We can either increase supply or reduce demand • Lowering demand • Politically difficult in the short term • Offers better economic returns • Causes less ecological and social damage • Increasing supply • Water can be transported through pipes and aqueducts • It can be forcibly appropriated from weak communities

43. Desalinization “makes” more water • Desalinization = the removal of salt from seawater or other water of marginal quality • Distilling = hastens evaporation and condenses the vapor • Reverse osmosis = forces water through membranes to filter out salts • Desalinization facilities operate mostly in the arid Middle East • It is expensive, requires fossil fuels, and produces concentrated salty water

44. Agricultural demand can be reduced • Look first for ways to decrease agricultural demand • Lining irrigation canals • Low-pressure spray irrigation that spray water downward • Drip irrigation systems that target individual plants • Match crops to land and climate (xeriscaping) • Selective breeding and genetic modification to raise crops that require less water Source: www.laspalitis.com

45. We can lessen residential and industrial water use in many ways • Eat less meat • Install low-flow faucets, showerheads, washing machines, and toilets • Use automatic dishwashers instead of washing dishes by hand • Water lawns at night, when evaporation is minimal, or replace lawn with native plants • Xeriscaping = landscaping using plants adapted to a dry environment

46. We can lessen residential and industrial water use in many ways • Shift to processes that use less water • Wastewater recycling • Excess surface water runoff used for recharging aquifers • Patching leaky pipes • Auditing industries • Promoting conservation/education 2012 RDN Water Systems Rate Structure

47. Economic approaches to water conservation are being debated • End government subsidies of inefficient practices • Let the price of water reflect its true cost of extraction • Industrial uses are more profitable than agricultural • Privatization of water supplies • May improve efficiency • Firms have little incentive to provide access to the poor • Decentralization of water control may conserve water • Shift control to the local level

48. Freshwater Pollution and Its Control 12-48

49. Freshwater pollution and its control • Water for human consumption and other organisms needs to be… • Disease-free • Non-toxic • Half of the world’s major rivers are seriously depleted and polluted • They poison surrounding ecosystems • Threaten the health and livelihood of people • The invisible pollution of groundwater has been called a “covert crisis”

50. Water pollution takes many forms • Pollution = the release of matter or energy into the environment that causes undesirable impacts on the health and well-being of humans or other organisms • Nutrient pollution • Pathogens and waterborne diseases • Toxic chemicals • Sediment • Thermal pollution