Determination of Soil Erosion Runoff using a Developed Laboratory Rainfall Simulator

Abstract

Using a developed rainfall simulator, soil erosion was studied in three representative soils in Auchi, Southern part of Nigeria. The runoff water and the quantities of the eroded sediments were measured with respect to soil type, slope and vegetal cover. Erosion from the simulated storm was greatly reduced by vegetative cover, declining from (3.32 - 4.48)*10^-3m³ for the exposed soil to (1.05 - 1.21)*10^-3m³, for the one covered with vegetation due to interception of raindrop by the leaves. However, increase in slope from 5^o through 15^o increased the runoff and quantities of eroded sediments slightly from (4.82)*10^-3m³ and 0.850 kg to (3.98)*10^-3m³ and 1.439kg respectively. The quantity of runoff for the three types of soil considered was more in sample C (sandy loam) with a value of (3.32)*10 ^-3m³ than the other soil types, sample A (silty clay) and sample B (clay soil) with runoff values of 4.48 and 4.38*(10^-3m³ respectively.

Keywords: soil erosion; slope; soil type; vegetation; rainfall simulator