Page 644 - 9780077418427.pdf

/Volume/201/MHDQ233/tat78194_disk1of1/0073378194/tat78194_pagefile
tiL12214_ch24_597-622.indd Page 621 9/23/10 11:09 AM user-f465
tiL12214_ch24_597-622.indd Page 621 9/23/10 11:09 AM user-f465 /Volume/201/MHDQ233/tat78194_disk1of1/0073378194/tat78194_pagefiles

46. Groundwater costs more for consumer use because 11. What factors determine the size of an ocean wave made by the wind?
a. it must be pumped to the surface. 12. Describe how a breaker forms from swell. What is surf?
b. it requires addition of bactericides.
13. Describe what you would look for to avoid rip currents at a beach.
c. filtration is needed to remove salts.
d. it is not chlorinated.
Answers FOR FURTHER ANALYSIS
1. b 2. c 3. c 4. b 5. b 6. b 7. c 8. b 9. c 10. d 11. a 12. c 13. c 14. c
15. c 16. c 17. b 18. a 19. c 20. b 21. b 22. c 23. b 24. b 25. a 26. c 1. Considering the distribution of all the water on Earth, which
27. d 28. a 29. c 30. b 31. d 32. b 33. a 34. a 35. b 36. c 37. a 38. c presently unavailable category would provide the most freshwater
39. a 40. c 41. b 42. c 43. b 44. b 45. d 46. a at the least cost for transportation, processing, and storage?
2. Describe a number of ways that you believe would increase the
amount of precipitation going into groundwater rather than runoff.
QUESTIONS FOR THOUGHT
3. Some people believe that constructing a reservoir for water storage
is a bad idea because (1) it might change the downstream habitat
1. How are the waters of Earth distributed as a solid, a liquid, and a below the dam and (2) the reservoir will eventually fill with silt
gas at a given time? How much of the water is salt water and how and sediments. Write a “letter to the editor” that supports the idea
much is freshwater? that a reservoir is a bad idea for the reasons given. Now write a
2. Describe the hydrologic cycle. Why is the hydrologic cycle second letter that disagrees with the “bad idea letter” and supports
important in maintaining a supply of freshwater? Why is the the construction of the reservoir.
hydrologic cycle called a cycle? 4. Explain how the average salinity of seawater has remained relatively
3. Describe in general all the things that happen to the water that constant over the past 600 million years in spite of the continuous
falls on the land. supply of dissolved salts in the river waters of the world.
4. Explain how a stream can continue to flow even during a dry spell. 5. Can ocean waves or ocean currents be used as an energy source?
5. What is the water table? What is the relationship between the Explain why or why not.
depth to the water table and the depth to which a well must be 6. What are the significant similarities and differences between a
drilled? Explain. river and an ocean current?
6. Compare the advantages and disadvantages of using (a) surface
water and (b) groundwater as a source of freshwater. INVITATION TO INQUIRY
7. Prepare arguments for (a) agriculture, (b) industries, and
(c) cities each having first priority in the use of a limited water
supply. Identify one of these arguments as being the “best case” Water Use
for first priority, then justify your choice. Investigate the source of water and the amount used by industrial processes,
8. Discuss some possible ways of extending the supply of freshwater. agriculture, and homes in your area. Make pie graphs to compare your
9. What is swell and how does it form? area to national averages, and develop explanations for any differences.
10. Why do waves always seem to approach the shore head-on? What could be done to increase the supply of water in your area?

PARALLEL EXERCISES

For additional parallel exercises on this material, see the chapter 24 resources at www.mhhe.com/tillery.
The exercises in groups A and B cover the same concepts. Solutions to group A exercises are located in appendix E.

Group A Group B
1. The availability of freshwater for surface water or groundwater, or 1. What is the net water budget for a region where the annual
net water budget, is assessed by comparing the precipitation in a rainfall is 890 mm and the potential evaporation (including
region to the amount of water that can potentially evaporate transpiration) is 635 mm?
(including transpiration). The difference between the two
determines whether a surplus or deficit exists in the net water
budget. What is the net water budget for a region where the annual
rainfall is 254 mm and the potential evaporation is 1,800 mm?
2. A location in the northeast United States receives 1,143 mm of 2. A location in the southeast United States receives 1,778 mm of
rainfall annually. The potential evapotranspiration (evaporation rainfall annually. The potential evapotranspiration (evaporation
and transpiration) is 508 mm. What is the net water budget of and transpiration) is 1,016 mm. What is the net water budget of
this region? this region?
3. On an annual basis, the precipitation in a watershed is 1,143 mm, 3. On an annual basis, the precipitation in a watershed is 1,778 mm,
the actual evapotranspiration is 558 mm, and 53 percent of the the actual evapotranspiration is 914 mm, and 61 percent of the
surplus precipitation is runoff. What is the percentage surplus precipitation is runoff. What is the percentage
contribution of each component of the watershed budget? contribution of each component of the watershed budget?

24-25 CHAPTER 24 Earth’s Waters 621