Detachment and Splash of a Cohesive Soil by Rainfall

Abstract

ABSTRACT TIME dependent relationships between soil detachment and splash, soil shear strength and the depth of ponded water on the soil surface are developed for Hagerstown silt loam under simulated rainfall. Soil splash rate was highly correlated to soil shear strength and increased exponentially from 26 kg/ha-min at initial conditions to about 149 kg/ha-min as the shear strength of the soil surface decreased as the soil water content approached saturation. After this point, the increasing depth of water ponded on the soil surface decreased the amount of soil splash by cushioning the impact of the rainfall. The soil splash rate decreased from 149 kg/ha-min at the start of ponding to zero when about four millimeters of water had ponded on the soil surface. The rate of accumulation of detached soil particles from the surface decreased with time and the depth of water ponded on the soil surface. This mass of suspended soil on the surface after 5 min was approximately ten times the mass of soil found in raindrop splash (2350 kg/ha vs. 171 kg/ha).