Integrating Google Earth Engine and GIS for RUSLE-based soil erosion and sediment yield assessment in Borkena Watershed, Ethiopia
摘要
Soil erosion is a significant environmental challenge in the Borkena Watershed, Awash Basin, Ethiopia, with adverse effects on agricultural productivity and water quality. This research article presents an innovative approach to soil erosion assessment by integrating Google Earth Engine (GEE) with earth observation (EO) and geographic information system (GIS) techniques. To compute soil erosion rates and pinpoint locations that are vulnerable to erosion, the Revised Universal Soil Loss Equation (RUSLE) model is utilized. The work uses high-resolution satellite imagery and digital elevation models (DEMs) from GEE to determine significant input parameters for the RUSLE model. The potential for soil erosion was determined by integrating rainfall erosivity, land cover, slope length, soil erodibility, and slope steepness within a GIS framework. The research outcome displayed that different parts of the watershed experience varied annual soil loss rates. In the lower part, no soil loss was observed, while in the middle section, the soil loss was measured at 5739.96 t ha−1 year−1. It has been established that the watershed’s yearly average soil loss was 25.49 t ha−1. Furthermore, the outcomes demonstrated that varying proportions of the research region were categorized into several groups according to the degree of soil erosion. Specifically, 64.58% of the area has been classified as “Very slight”, 7.23% as “slight”, 8.02% as “moderate”, 6.78% as “high”, and 13.39% as “very high”. These divisions were established according to the following value ranges: 0–11, 11–18, 18–30, 30–50, and more than 50 t ha−1 year−1, in that order. From the total watershed area of 162,727.52 ha, the anticipated annual sediment yield was 116,203.56 tons. The findings reveal significant variations in soil erosion rates across the Borkena Watershed, with higher erosion potential observed in areas characterized by steep slopes, intensive agriculture, and limited vegetation cover. To reduce soil erosion and protect soil resources, land management techniques, and focused interventions can be guided by the geographical distribution of regions prone to erosion. To monitor and control soil erosion in the Borkena Watershed, the method described here provides land managers, policymakers, and researchers with a useful tool that can be replicated in similar regions facing soil erosion challenges.