Assessment of soil erosion hotspots and the control technologies in Sisiyi Subcounty, Bulambuli District, Mountain Elgon
Abstract
Soil erosion is responsible for reduced productivity of both upstream and downstream soils through the processes of dislodging and deposition. This study aimed at assessing the soil erosion risk areas within Sisiyi Sub County and the variations in the adopted soil erosion control technologies and factors influencing the adoption of these technologies by farmers in the middle slopes of Mt. Elgon in eastern Uganda. The RUSLE equation using GIS application tools the ESRI ArcGIS software (10.5 version) was used in developing maps from equations made by the raster calculator. The DEM data was used to estimate slope gradient, flow direction, catchment area and flow accumulation. The shape files used include rainfall, land use/cover, slope and soils.
The maps developed depicted that grassland and croplands indicated the highest soil loss estimates that are distributed in the areas with a gentle slope of 23 - 430 and rainfall intensity ranging from 36 – 40 mm. The smallest portion (20 percent) of the small- scale farming was attributed to soil loss of an annual average of 24,005- 69,557 ton/ha. The highest Soil losses along crop lands and grasslands were common in Dark brown clays and clay loams soil type prone areas. Majority of the farmers (48 %) had no soil erosion control methods. This was followed by plots where only terraces (18 %), less than 10 % of the plots had a combination of terraces and grass bunds. The findings from this study to contribute to a better understanding of the erosion hotspots thus proper decision making on the protection recommendations of these hotspots areas.