A Hidden Reserve Groundwater Test Bank Docx Ch16

CHAPTER 16: A Hidden Reserve: Groundwater

LEARNING OBJECTIVES

16A. Explain what groundwater is, where it resides in the Earth, and how its composition and flow varies.

16B. Characterize porosity and permeability.

16C. Describe the difference between aquifers and aquitards and the nature of the water table.

16D. Differentiate among the various types of wells and springs that provide access to groundwater.

16E. Produce a sketch showing how hot springs originate.

16F. Explain how groundwater supplies can be damaged or depleted and how to address these problems.

16G. Describe how caves and karst landscapes originate and evolve.

MULTIPLE CHOICE

1. The liquid freshwater that occurs within sediments and rock below the Earth’s surface is called

2. Approximately how much of our global freshwater resources are supplied by groundwater?

3. What is infiltration?

4. An aquifer has ________ porosity and ________ permeability.

5. Igneous rocks typically have few fractures and few if any pore spaces. In other words, unfractured igneous rocks often exhibit _______ porosity and _______ permeability.

6. The wide and long fractures in this limestone cause it to have

7. Material through which water readily flows is termed ________.

8. A porous material

9. Porosity is best described by which of the following?

10. The dissolution of rock produces ________.

11. Imagine two rocks with the same porosity. Rock A has many small pores connected by thin and winding conduits, while Rock B has fewer but larger pores connected by straight conduits. Which rock is likely to have higher permeability?

12. How can a rock or sediment have high porosity but low permeability?

13. A layer of gravel, where the sediment grains do not fits together tightly, is likely to exhibit

14. An impermeable layer of rock or sediment is a(n) ________.

15. In a confined aquifer there is likely to be an aquitard located ______ relative to the aquifer.

16. Which of the two figures below best shows the location of the water table expected in a dry climate?

17. The pore spaces in rocks, soils, and sediments that are only partially filled with water occur in the

18. The water table surface mimics the topography in an area because ________.

19. At which point this diagram would water pressure be greatest?

20. In which direction would you expect groundwater to be moving in this diagram?

21. The elevation of the water table ________.

22. As a rule, groundwater always flows from areas of ________.

23. The volume of groundwater flow over a given time per unit area through a body of rock or sediment is called

24. In the figure below, where is the discharge area for water infiltrating to the water table at point h₁?

25. The lines with arrows in the figure below show several long-distance groundwater flow paths you could expect in a landscape adjacent to a mountain range. Along which flow path is water likely to take the most time between recharge and discharge?

26. In what direction does water flow in the unsaturated zone?

27. For a well to function properly, it must be drilled below the water table and into a(n) _________.

28. Hard water results from relatively high concentrations of dissolved ________.

29. You are testing the groundwater quality of an aquifer and find that it has high amounts of arsenic. What is the likely source?

30. What does it mean if the potentiometric surface does NOT reach above the ground surface?

31. You have a choice to drill your water well into a shallow unconfined aquifer or a deeper artesian aquifer. Drilling deeper will cost more money; nevertheless, you chose to drill into the artesian aquifer. Why?

32. In the figure below, there are springs located along the surface trace of the fault. Given that the recharge area for these springs is located in the rocks on the left of the figure, what can be said about rock unit A on the right side of the fault?

33. A well that does not penetrate below the groundwater table is called a(n)

34. What is the purpose of the great height of the water tanks used in the water supply systems of many towns?

35. Hot springs can be formed by the heating of groundwater by magma or by ________.

36. A periodic explosive eruption of steam and water from within the ground up through the surface is termed a(n) ________.

37. How does the composition of water in hot springs compare to average groundwater?

38. Where did our word geyser originate?

39. Old Faithful in Yellowstone National Park is an example of a(n)___________.

40. Pumping vast quantities of water locally ________.

41. Imagine that some of the wells around a city have begun to show elevated levels of a toxic substance. Without knowing what the toxic substance is, how can you use groundwater characteristics to determine what the source of the chemicals might be?

42. Land subsidence is likely when ________.

43. Groundwater depletion occurs when

44. In coastal communities, high rates of fresh groundwater withdrawal can raise the boundary between fresh and underlying saltwater aquifers and contaminate water supplies with salt. This process is called

45. A(n) ________ aquifer is more likely to be contaminated than a(n) ________ aquifer.

46. Why would a rise in the water table be a potential danger to a homeowner?

47. Topography dominated by depressions formed by the collapse of caves is termed a ________.

48. The majority of large cave and karst systems have resulted from ________ etching into ________.

49. Common features in caves include stalactites, which _______ and stalagmites, which ________.

50. The collapse of the land surface into an underground cavern results in a feature called a

1. What are porosity and permeability, and how do they affect the rate of groundwater flow?

2. Vesicular basalt has high porosity but very few fractures. Its pores are isolated and not well connected to each other. Would this basalt then make a good aquifer? Why or why not?

3. In the image below, label the confined aquifer, the unconfined aquifer, and the aquitard. If you were to drill a well for personal use in this region, in which of these three layers would you put your well? Why?

4. On the image below, identify the drainage divide and regions of discharge and recharge, and label the water table. Then draw arrows showing the flow of groundwater.

5. Label the three zones, on the image below, that water moves through as it percolates into the Earth. Also include where the water table is by marking it with an arrow.

6. The commercial distribution of bottled “spring water” has become a major business worldwide, and many people think that this water offers health benefits. Evaluate this belief. How is spring water different from groundwater?

7. The images below are of two different geological scenarios in which springs could form. Describe the similarities and differences between these two scenarios.

8. What are some ways that a rise in the water table could be damaging or hazardous?

9. List and describe one possible effect of overpumping.

10. Explain how limestone caves are formed, making sure to include the name of the acids involved and how they form.