Assessing Soil Erosion in the Ghorautra River Basin of Bangladesh: Using SCS-CN and RUSLE Methods within the GIS-RS Framework
摘要
Soil erosion and runoff are complex natural phenomena that have significant impacts on environmental stability, agricultural productivity, and water resource management. It is crucial to determine soil erosion hotspots and runoff patterns in a drainage basin to alleviate the potential erosion by adapting potential measures. This study, however, aims at predicting runoff and the consequent soil erosion using the SCS-CN and RUSLE models, respectively during the period 2010 to 2020 in the Ghorautra River Basin of Bangladesh. As input parameters, these models required spatiotemporal data sets of precipitation, topsoil textures, hydrologic soil groups, land use, and land covers. According to the SCS-CN model, it was found that the basin experienced its highest runoff of 1698 mm in 2017 and the lowest of 107 mm in 2012. Furthermore, the average annual runoff obtained 564.90 mm, or 9.49 × 108 m3 yr−1 in volumetric scale which was 21% of the average yearly rainfall occurred in the study area. For the erosion scenario, the output of the RUSLE model revealed that an annual average soil erosion rate of 0.77 t ha−1 yr−1, resulting in a substantial loss of 0.13 million tons of topsoil per year. The analysis indicates the highest average soil erosion in the study area was 1.12 t ha−1 yr−1 resulting in an alarming loss of 0.28 million tons of topsoil in 2017 surpassing the values predicted in other years. This study highlights a rapid characterization of soil loss rates which is alarming for the basin. Therefore, these findings can be utilized to prioritize erosion mitigation plans, thereby promoting sustainable land resources and addressing land degradation challenges in the Ghorautra River Basin.