Some effects of surface cover geometry on infiltration rate

Abstract

Infiltration into the soil is regulated in part by sealing of the soil surface by raindrop impact. Soil surfaces protected from such impact maintained higher rates of infiltration than exposed soil surfaces. It was hypothesized that the cover particles protected the covered portion of the soil and prevented the reaction of raindrop impact on the soil state. The soil under the cover particles remained in the original state in which infiltration could occur. However, since the cover particles in this study were impervious, infiltration could not occur on the covered area but would occur along the available perimeter of the cover particles. Water would then move in both vertical and lateral directions. The effective lateral distance that the water moved after entry was defined as the effective width. To evaluate the effects of soil surface cover on the infiltration rate of soils exposed to raindrop impact, simulated rainfall was applied at a constant rate to one soil type in small plots with free drainage, and square and rectangular cover particles of varying sizes and percentages were used as surface cover.