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Environmental Engineering for Flood Control Channels


Quiz Questions

1.Deposition of sediment in a channel, on a floodplain, or other surface in sufficient quantity to increase local elevation is called ________________.
Aggradation
Armor
2. A plate, wall, screen, or other device to deflect or impede flow is called ___________.
Baffle
Benthic
3.Gravel and stones that have been rounded by abrasive action of flowing water or waves is known as ________.
Cobble
Gabion
4. A stream that ceases to flow seasonally or occasionally because bed seepage and evaporation exceed the supply of water is known as intermittent stream.
True
False
5.An embankment constructed to provide flood protection from seasonal high water is known as leeching.
True
False
6.Meander is a broad, looping bend in a stream channel.
True
False
7. Oxbow lake is a lake formed in a former stream meander that has been abandoned naturally or cut off during channel construction for navigation or flood control purposes.
True
False
8. A topographically high area in a channel created by the accumulation of relatively coarse-grained sediments is termed to be a riffle.
True
False
9._________________ represents the typical physical changes and attendant environmental impacts due to channel modification without environmental design components.
Figure 2-1
Figure 2-2
10.Floodways (sometimes called bypass or diversion channels) are excavated channels that convey floodwaters over routes that are usually shorter and straighter than those followed by the unmodified stream. Floodways normally are designed to convey flood flows only, and low and normal flows are diverted through the natural channel.
True
False
11. High-flow channels are flood control channels with modified cross sections that include a subchannel with high-flow berms on one or both sides. High-flow berms are inundated infrequently and may be used for parks, trails, or other purposes compatible with their functions as flood channels.
True
False
12. Figure 4-2 represents the typical flood channel cross sections.
True
False
13. _________________ represents the single-bank construction.
Figure 4-3
Figure 4-4
14.The major steps in conducting environmental studies are shown in __________________.
Figure 6-1
Figure 6-2
15. Wing deflector is a low structure projecting from a channel blank used to create scour holes for fish habitat purposes.
True
False