Single rain drop

Rain may move soil directly: this is known as 'rainsplash erosion' (or just 'splash erosion').

Spash is only effective if the rain falls with sufficient intensity.

As runoff moves downhill, it is at first a thin diffuse film of water which has lost virtually all the kinetic energy which it possessed as falling rain.In many parts of the world, rill and gully erosion is the dominant form of water erosion. with too high an intensity) for it to infiltrate: the runoff which results is then known as infiltration excess runoff, or Hortonian runoff.That fraction of the rainfall which does not infiltrate (soak into) the soil will flow downhill under the action of gravity; it is then known as runoff or overland flow. Secondly, runoff may occur if the soil has already absorbed all the water it can hold (i.e.Because rainsplash requires high rainfall intensities, it is most effective under convective rainstorms in the world’s equatorial regions.Rainsplash is relatively ineffective where rain falls with a low intensity (e.g.

Although considerable quantities of soil may be moved by rainsplash, it is all merely redistributed back over the surface of the soil (on steep slopes, however, there will be a modest net downslope movement of splashed soil).

Thus a more descriptive term might be 'rainsplash redistribution'.

If it does, then as the raindrops hit bare soil, their kinetic energy is able to detach and move soil particles a short distance.

Because soil particles can only be moved a few centimetres at most by this process, its effects are solely on-site.

because it is fully saturated, or if the soil is frozen).

Runoff which results from this situation is known as saturation excess runoff.