Water Droplet Impact and its Effect on Infiltration

Abstract

ABSTRACT THE effect of droplet impact on the infiltration characteristics of a Warden silt loam soil were investigated in the laboratory. The hydraulic resistance of the seal formed on the soil surface by impacting water droplets was found to increase with increasing droplet kinetic energy per unit soil surface area (KEa). Experimental data also showed that the depth of water infiltrated prior to surface ponding decreased with increasing application rate (rainfall intensity), kinetic energy per water droplet (KEd), and water droplet energy flux (DEf). A unique relationship between DEf and the depth infiltrated prior to ponding was noted for the Warden silt loam. A procedure for determining the depth of water that can be applied to the Warden silt loam without the potential for runoff based on this relationship and an equation for computing DEf was presented. It appears that DEt, which is a function of both application rate and KEd, may be more effective in evaluating the runoff potential of irrigation sprinklers and rainstorms than application rate alone on soils prone to surface sealing such as the Warden silt loam.