Rainfall intensity and soil physical properties influence on infiltration and runoff under in-field rainwater harvesting conditions. (Special Issue: Rainwater harvesting and conservation techniques for improving household food security.)

摘要

The objective of this study was to quantify the combined influence of rainfall intensity and soil physical properties on infiltration and runoff under in-field rainwater harvesting (IRWH). Rainfall intensities and soil physical properties were mathematically related to time to runoff, time to final infiltration rate and final infiltration rate. The influence of rainfall intensity and soil physical factors on rainwater harvesting under IRWH was demonstrated. A commercial field, divided into 75 plots and under IRWH located near Bloemfontein, South Africa, was used. Nine plots were selected to obtain the widest range of clay plus silt content possible. Three rainfall intensity treatments were applied using a mobile rainfall simulator. Before the start of the simulations soil samples were taken to determine the soil's physical properties. A multiple regression analysis showed that the infiltration and runoff process depended primarily on rainfall intensity and soil physical conditions. The in-field runoff analysis showed that for every 1 mm of rain that infiltrated in the runoff strip, between 2.18 and 6.48 mm would infiltrate in the basin strips. Thus, the soil types tested had a huge potential for water harvesting practices.