Page 84 - Soil Degradation, Conservation and Remediation

3.3 Types of Water Erosion 71

Fig. 3.1 Splash erosion (Photo courtesy of Dr. Lasikaamarasena)

transport of the detached particles by runoff water. Runoff water laden with
suspended particles also detaches more soil particles in its way across the surface.
Soil erosion is a process of soil loss, particularly from the surface, but sometimes a
large mass of soil may be lost, as in landslides and riverbank erosion. Kohnke and

Bertrand ( 1959 ) classified water erosion into sheet erosion, internal erosion, and
channel erosion. Channel erosion was further divided into rill erosion, gully ero-
sion, and stream erosion. However, the following four types of water erosion are
generally recognized: splash erosion, sheet erosion, rill erosion, and gully erosion.
Splash and sheet erosion are sometimes called interrill erosion.

3.3.1 Splash Erosion

At the start of a rain event, falling raindrops beat the soil aggregates, break them,
and detach soil particles. These particles clog the large soil pores and, thus, reduce
the infiltration capacity of the soil. Water cannot enter the soil, and soon a thin fi lm

of water covers the ground. Further, raindrops beat the water and splash the sus-
pended soil particles away. Soil particles are transported to some distance by the
splashing. The splashed particles can rise as high 60 cm above the ground and move
up to 1.5 m from the point of impact. Processes of splash erosion involve raindrop
impact, splash of soil particles, and formation of craters (Ghadiri 2004 ). Actually,
splash erosion (Fig. 3.1 ) is the beginning of other types of soil erosion, particularly
sheet erosion .