Surface Runoff and Soil Loss Under Varying Rainfall Intensity : SURFACE RUNOFF AND SOIL LOSS UNDER VARYING RAINFALL INTENSITY IN SELECTED LAND USE PRACTICES FROM RIVER NJORO CATCHMENT-KENYA

The Mau forest complex has experienced forest destruction to make room for cultivation from as early as 1970s. This has had a disastrous effect on forest cover. The changing land use has resulted in reduced water retention capacity and increased soil erosion in the catchment. Consequently very large peaks and low flows with frequent drying up in the lower reaches are common in River Njoro. Due to increased erosion, the river deposits so much sediments into Lake Nakuru. The study investigated the effect of rainfall intensity on soil erosion and surface runoff on different land use practices. Field rainfall simulation at different rainfall intensities was used to examine infiltration, surface runoff and soil loss on natural forest, agricultural and grazing lands.The study found that there was a significant difference in the mean runoff rate and soil lost from the three land use practices. Soil loss increased as rainfall intensity increased.However, the highest mean runoff rate was recorded from grazing area followed by agricultural while forested area recorded the least runoff rate.These results are useful in prioritizing interventions for land and water management