1 Canadian Geography Chapter 7 Water

2 The oceans cover 70% of our planet Our bodies contain 65% water Water is one of Canada’s most valuable resources( we have 9% of the world’s total renewable fresh water

3 1. Hydrologic Cycle Is the constant movement and evaporation of water from the oceans, lakes and other bodies of water.( Cycling and recycling of water) Questions : Refer to fig7.5 pg Questions : Refer to fig7.5 pg A. Sketch the diagram and be sure to label B. List 5 ways people use water as it moves through the hydrologic cycle? C. Explain why water is a renewable resource.

4 Animation: urces/geog/hydro_cycle/hydro/cycle.htm urces/geog/hydro_cycle/hydro/cycle.htmhttp:// urces/geog/hydro_cycle/hydro/cycle.htm

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6 The hydrologic cycle begins with the evaporation of water from the surface of the ocean. As moist air is lifted, it cools and water vapor condenses to form clouds. Moisture is transported around the globe until it returns to the surface as precipitation. Once the water reaches the ground, one of two processes may occur; 1) some of the water may evaporate back into the atmosphere or 2) the water may penetrate the surface and become groundwater. Groundwater either seeps its way to into the oceans, rivers, and streams, or is released back into the atmosphere through transpiration. The balance of water that remains on the earth's surface is runoff, which empties into lakes, rivers and streams and is carried back to the oceans, where the cycle begins again. evaporationcondensestransportedprecipitation groundwatertranspirationrunoffevaporationcondensestransportedprecipitation groundwatertranspirationrunoff

7 2. Definitions Students should define the following terms: Groundwater, drainage basin, water table, aquifer, watershed, oxbow lake, floodplain, sediment, water wealth, transpiration. Definitions found in glossary or on pgs

8 3. Streams in the drainage basin: (pg ) A. Youthful Stream- occupy v-shaped valleys and they erode down ward into the highest part of the drainage basin.

9 B. Mature Stream – the increased water flow from the youthful stage causes wide curves or meanders. These meanders cut into the stream banks and widen the valley into a narrow u-shape.

10 C. Old Age Stage- there is one meandering channel and regular flow The large meanders become so curved that they cut off to form horseshoe- shaped water bodies called oxbow lakes. During heavy rainfall the river might over flow it’s banks.

11 Animationhttp:// bjects/geography/rivers/River%20Articles/ oxbowlake.htm bjects/geography/rivers/River%20Articles/ oxbowlake.htmhttp:// bjects/geography/rivers/River%20Articles/ oxbowlake.htm

12 4. Runoff Rates The runoff rate or amount of water moving over the ground determines the size of the water supply. Runoff rates are affected by: A. slope of the land B. temperature C. vegetation cover D. soil and rock types E. intensity of precipitation

13 Open text book to pg.113 and complete questions 13 and 14. Go to page 116 and do question 18 and 19 a and b.

14 5. Classifying water use: A. Withdrawal- is when water is removed from it’s natural location. ( water used in homes, farms, businesses and industry.) B. Instream- is when demand does not remove the water from it’s natural location. (fishing, swimming, canoeing and shipping) Q. Identify 10 ways in which water is used and indicate whether it is withdrawal or instream?

15 6.Two problems with our water supply: A. Water supply is too small to meet the demands placed upon it. B. The quality of our water is reduced as a result of misuse or pollution.

16 7. Dams and diversions Uses of Dams: A. To store the excess flow of rivers during wet periods for use in drier season. B. They also divert water from one drainage basin to another.

17 8. Climate change and water supply Global warming- many scientists believe that rising levels of carbon dioxide in the earth’s atmosphere will bring major climatic changes to countries like Canada. One predicted change is an increase in temperatures of 1.5 to 4.5 degrees over the next fifty years.

18 Animation: alwarming/kids/global_warming_ve rsion2.html alwarming/kids/global_warming_ve rsion2.htmlhttp:// alwarming/kids/global_warming_ve rsion2.html Refer to pages 121 and122 and list four positive and four negative effects of global warming?

19 9. Canadian water exports Arguments for: U.S. will pay for the construction of canals and pipelines to move water south. Drier regions in Canada could avail of the water as well. U.S. would employ Canadians thus creating hundreds of thousands of jobs during construction.

20 About 50% of the equipment and materials required for the project would be sourced in Canada. Water is a resource and we already export other resources and this could create employment and generate revenue Much of our freshwater flows unused in the north and why not divert it and make money

21 Arguments against: Perhaps we will need this water in future years. If we start exporting it will be difficult to stop the exporting. If lake levels fall because of the greenhouse effect, Canadians may require this water

22 The waters of Southern Ontario are already polluted and if we continue to contaminate other waters we may need the pollution free water from the north. Americans need better water management and conservation, there needs can be satisfied internally.

Problem of water quality Question: Refer to fig7.21 on pg.125 and list four ways in which toxic chemicals enter and pass through the hydrologic cycle.

Four (4) steps for cleaning up the Great Lakes A. identify the most seriously polluted areas B. track down the sources of the contaminants C. restrict the release of these toxins into the environment D. clean up those areas that were already contaminated