Relative Detachability of Soil Particles by Simulated Rainfall

Disturbed surface soil masses of two coarse‐grained granitic soils and a single fine‐textured clay soil were subjected to simulated rainfall. The relative detachability of 11 soil‐size fractions was determined by comparing the proportion of a given size fraction in the pretreatment soil mass with the proportion of that size fraction in the splashed soil. Tests were conducted under two levels of rainfall intensity, three degrees of slope steepness, and in the presence or absence of overland flow. Effects of rainfall intensity and slope steepness were small. Overland flow had a pronounced effect on particle detachment resulting from raindrop impact. Without overland flow, soil particle sizes in the range of 110–1,450 µm were most susceptible to detachment by raindrop impact. With overland flow, the susceptible size range was 219–2,034 µm.