Depence of Man on the Environment Chapter 10 Answers

Chapter 10 Questions

1. Describe the path a molecule of water might follow through the hydrologic cycle from the ocean to land and back again.

Answer: water evaporates from the oceans to form clouds that are moved over land by prevailing winds and then rainfall brings it to earth where it is returned to oceans by tributaries and rivers.

2. Describe at least one example of the environmental costs of water diversion from rivers to farms and cities.

Answer: Several consequences of river diversion for irrigation are: downstream river discharge is reduced, the evaporation in the overall irrigation region is increased, the groundwater recharge in the region is increased, the level of the water table rises, and the drainage flow is increased. Just in the first category, reduced downstream river discharge, effects can include reduced flooding, disappearance of wetlands and flood forests, reduced availability of potable water, reduced shipping routes, and reduced fishing opportunities.

3. Explain the difference between point and nonpoint pollution. Which is harder to control? Why?

Answer: Non-point source pollution is pollution that comes from a collective of contaminants that cannot be traced to any one source. These would be run-off from agriculture or dumping into a waterway. A point source is pollution that can be traced to one contributor, such as a particular drain pipe from a factory.

4. What changes might occur in the hydrologic cycle if our climate were to warm or cool significantly?

Answer: Warming results in higher ocean levels and more surface area. This results in increased evaporation. This results in more rain. We should see an increase in usable and livable land.

5. Under what conditions might sediment in water or cultural eutrophication be beneficial? How should we balance positive and negative effects?

Answer: Sediment is important in depositing new soil in delta areas for better crops.

Eutrophication is the addition of phosphates and other plant nutrients to the water causing excessive plant growth, then the lower areas die without sun, and the decomposition of the dead material uses too much oxygen and fish die. cultural eutrophication indicates that man is involved. We hav removed phosphates from detergents, but farming and golf courses and other things still contribute to pollution in the Chesapeake.

Chapter 11 Questions

1. How does tectonic plate movement create ocean basins, mid-ocean ridges, and volcanoes ?

Answer: At the boundaries of tectonic plates you get a lot of emission of various gasses either from hydrothermal vents at mid-ocean ridges or from volcanoes near plate subduction zones. These gasses typically comprise things like sulphur dioxide and carbon dioxide that can have big impacts on climate and ocean chemistry. Another major impact on the environment from plate tectonics is mountain building, such as when two plates collide to form large mountain ranges such as the Himalayas. Big mountain ranges can have huge affects on weather patterns and precipitation. The Asian monsoons are heavily influenced by the Himalayan plateau for example. Also, weathering of mountain ranges can alter the atmospheric and ocean composition due to the chemical processes involved. Finally, as plate tectonics causes the continents to shift position it will have a direct effect on ocean circulation and how heat is distributed around the planet, as well as those continents shifting to different latitudes and climate regimes.

2. Describe some of the mining, processing, and drilling methods that degrade water and air quality.

Answer: In hydrology, water mining is the extraction of water from non-replenishing groundwater or glacial reserves. By necessity, any community engaging in water mining will