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 Oxygen acting on iron tributaries. A divide separates two drainage basins. Burrowing animals 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 Base Level V-shaped valley 13.3 River Valleys After You Read 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. 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 Reservoirs can store excess runoff Allows deeper river to hold more water Cannot prevent floods If dam breaks, resulting flood is worse than without dam Deeper depth of river produces greater velocity and greater erosive force 13.4 Floodplains and Floods 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.