Page 251 - Soil and water contamination, 2nd edition

238 Soil and Water Contamination

a. Calculate the total amount of sediment that is deposited in the 1 ha of floodplain
during one day.
b. What would happen if water stopped flowing over the floodplain?

5. Describe the limitations of Stokes’s law for calculating the settling velocity of suspended
solids in natural surface waters.
6. Name two main effects of flocculation on sediment deposition.

7. A hill slope in the loam belt of Belgium is 150 m long (measured from the local drainage
divide) and can be subdivided into three sections of 50 m, each with a different gradient.
The slope angles of the sections are:

Section Slope angle (%)
1 5
2 10
3 3

a. Estimate the long-term interrill erosion rate, rill erosion rate, and transport capacity
at the end of each section (i.e. 50 m, 100 m and 150 m from the drainage divide),
given f = 120 m. Note that the slope angles are given in percentages.
b. Give the cumulative total erosion rate and transport capacity as function of slope
length for each section.
c. Evaluate the fate of the eroded sediment on this hill slope.

10/1/2013 6:45:09 PM
Soil and Water.indd 250
Soil and Water.indd 250 10/1/2013 6:45:09 PM