Question 18.11

Why might the flow of a very small, shallow stream be laminar in winter and turbulent in summer?

Question 18.12

Describe and compare the floodplain and valley above and below the waterfall shown in Figure 18.13.

Question 18.13

You live in a town on a meander bend of a major river. An engineer proposes that your town invest in new, higher artificial levees to prevent the meander from being cut off. Give the arguments, pro and con, for and against this investment.

Question 18.14

In some places, engineers have artificially straightened a meandering stream. If such a straightened stream were then left free to adjust its course naturally, what changes would you expect?

Question 18.15

If global warming produces a significant rise in sea level as polar ice caps melt, how will the longitudinal profiles of the world’s rivers be affected?

Question 18.16

In the first few years after a dam was built on it, a stream severely eroded its channel downstream of the dam. Could this erosion have been predicted?

Question 18.17

Your hometown, built on a river floodplain, experienced a 50-year flood last year. What are the chances that another flood of that magnitude will occur next year?

Question 18.18

Define the drainage basin where you live in terms of the divides and drainage networks.

Question 18.19

What kind of drainage network do you think is being established on Mount St. Helens since its violent eruption in 1980?

Question 18.20

The Delaware Water Gap is a steep, narrow valley cut through a structurally deformed high ridge in the Appalachian Mountains. How could it have formed?

Question 18.21

A major river, which carries a heavy sediment load, has no delta where it enters the ocean. What conditions might be responsible for the lack of a delta?