Chapter 13 Worksheets

Section 1-4

13.1 After You Read: Streams and Rivers

1. What is a drainage basin, or watershed? What separates two drainage systems from each other?

A drainage basin, or watershed, is all of the land that drains into a certain river and its tributaries. A divide separates two drainage basins.

Burrowing animals

Oxygen acting on iron

13.1 After You Read: Streams and Rivers

Gradient

Discharge

Size and shape of channel

How much energy river has to erode materials

13.2 Stream Erosion and Deposition

1. What is the difference between a stream’s competence and its capacity?

The competence is the maximum size of the particles a stream can carry, while capacity is a measure of the total amount of sediment it can carry.

13.2 After You Read: Stream Erosion and Deposition

In suspension

In bed load

In solution

In bed load

In suspension

In bed load

In solution

In suspension

13.3 River Valleys

Gully

Canyon V-shaped valley

Base Level

1. Explain how Niagra Falls illustrates the process of recession by undermining.

Niagra Falls’ falling water erodes the shale rock around its plunge pool, leaving the overhanging layer of dolomite rock unsupported.

ES1305 – Waterfall Erosion

13.3 River Valleys After You Read

2. How can headward erosion lead to stream piracy?

When land is worn away at the head of a stream and the stream eventually breaks through a divide, the first stream can capture the headwaters of a second river.

13.3 River Valleys After You Read

Headward Erosion

13.4 Floodplains and Floods

List the advantages and disadvantages, or limitations, of three methods of flood control; replanting where vegetation has been removed, building dams, and building artificial levees.

Can reduce runoff Cannot prevent floods

Reservoirs can store excess runoff

If dam breaks, resulting flood is worse than without dam

Allows deeper river to hold more water

Deeper depth of river produces greater velocity and greater erosive force

List three human activities that can cause or worsen floods and tell how they cause problems.

Covering land with pavement makes land unable to absorb water; removing vegetation from slopes increases runoff; and development displaces the wetlands that would otherwise act as natural sponges.

13.4 Floodplains and Floods