Soil hydrophobicity effects on rainsplash: Simulated rainfall and photographic evidence

Laboratory rainfall simulation experiments indicate greater splash losses for hydrophobic (water repellent) than for wettable sandy loam soils at different rainfall intensities, durations and soil surface inclinations. Using synchronized video cameras with different shutter speeds and stroboscopically illuminated 35 mm still photography, differences in splash droplets and ejection trajectory characteristics are examined. For hydrophobic soil, raindrop impact gives rise to fewer, larger, slower-moving daughter ejection droplets which carry more sediment and hence follow shorter range trajectories compared with wettable soil. Implications for erosion of hydrophobic soils are discussed.     

Field measurements of rainfall drop-size distribution,and the relationships between rainfall parameters and soil movement by rainsplash

Rainfall drop-size distributions were measured at a site in northern England using the ‘oflour-pellet’ technique. A relationship between intensity and kinetic energy is presented. Even at the low rainfall intensities observed (< 5 mm h^?1 average over an hour) measureable amounts of rainsplash movement took place, and these movements have been related to rainfall parameters.