Review Questions for Program #19: Running Water 1
Please fill out and return this sheet after viewing
Program #19. If you are unsure of an answer, give your best
intelligent guess.
1. Besides river and streams, where else does rainfall go?
It percolates into the ground as groundwater and can evaporate into the atmosphere.
2. What factors affect the velocity of a river?
The river's gradient, the shape of the river channel, the roughness of the channel bottom
3. What is a river's discharge?
The volume of water that flows passed a particular point in a given amount of time.
4. What are the three types of sediment load of a river? Describe each type.
Bed load -- larger sediments that may move along the bottom of the river channel by rolling, sliding or hopping short distances.
Suspended load -- smaller sediments (silt, clay) that remain suspended in the stream by the turbulance of the river water activity.
Dissolved load -- material that is dissolved by river water (salts)
5. What conditions produce a braided stream?
High sediment load in river; little vegetation (desert type climates)
6. How do meanders evolve over time?
Meanders become more exaggerated over time; the outside bend erodes away, and the inside part of the bend builds out. In time a meander develops a very narrow neck that is eventually cut off, leaving the old meander isolated from the river as an oxbow lake.
7. What are flood features of a river?
Flood plains; natural levees; yazoo tributaries; backswamps
8. What are the benefits and drawbacks of dams?
Benefits -- provide electric power, flood control,
irrigation, drinking water, recreation
Drawbacks -- dams withold sediment transport
downstream, and instead encourage higher rates of downstream erosion;
by witholding sediments, dams prevent many beaches from receinving replenishing
sediment.
9. Where in a river does water flow fastest?
In the center surface of a river.
10. What is a government agency that is interested in maintaining flood control on rivers?
U.S. Army Corps of Engineers