Wind effects on soil erosion by water - A sensitivity analysis using model simulations on catchment scale

- EROSION 3D considers the impact of wind speed and direction on soil erosion by water.
- The approach uses vectorial variables instead of scalar ones.
- Soil erosion by water is substantially affected by wind speed and direction.

Soil erosion by water is affected by raindrops hitting the soil surface. Under windy conditions the droplets are forced to divert from vertical fall which affects their erosional intensity. To consider this effect the paper reports on model simulations with the EROSION 3D model taking into account wind speed and wind direction.Based on measured data achieved by wind tunnel experiments a set of algorithms was derived, which describes the diversion angle of rain drops as a function of wind speed and the resulting impact angle on inclined slopes as a function of wind direction. Using a small catchment in the ore mountain range of Saxony/East Germany as example several test runs were performed comparing wind impact from different directions (north, east, south, west) with no wind conditions. Model simulations based on these scenarios result in plausible estimations of soil loss under wind impact and improve the understanding of wind impacted soil erosion which cannot be measured yet on catchment scale. As the simulated scenarios show erosion can be increased as well as decreased due to wind impact. The effect of wind impact on soil erosion by water is substantial and thus it should not be neglected in mathematical soil erosion models.