The action of water in arid regions
301
Figure 13.17. Sketch of the effect of a rainsplash (A1-Durrah and Bradford, 1982).
when the run-off is concentrated in small areas of irregular topography. Rill erosion,
however, does not occur until the erosive capacity of the flow exceeds the resistance to
mobilization of the soil particles, meaning that the run-off may flow a considerable
distance over the slope before rills develop (Meyer, 1986). Once the rill is formed, flow
increases rapidly and erosion is increased down the slope. The mechanisms that form rills
are very complex, as indicated by the fact they may also proceed backwards from the rill
head (Bryan and Poesen, 1989).
301
Figure 13.17. Sketch of the effect of a rainsplash (A1-Durrah and Bradford, 1982).
when the run-off is concentrated in small areas of irregular topography. Rill erosion,
however, does not occur until the erosive capacity of the flow exceeds the resistance to
mobilization of the soil particles, meaning that the run-off may flow a considerable
distance over the slope before rills develop (Meyer, 1986). Once the rill is formed, flow
increases rapidly and erosion is increased down the slope. The mechanisms that form rills
are very complex, as indicated by the fact they may also proceed backwards from the rill
head (Bryan and Poesen, 1989).