Soil Erosion mapping using Remote Sensing and GIS - A case study of Rewa River Watershed, Naitasiri province, Fiji

Abstract

Rewa river watershed covers approximately up around 33% of the Viti Levu’s total Land area in Fiji’s central division. Due to anthropogenic development activities, this region has undergone soil erosion and flooding. Soil erosion leads to a variety of environmental issues, with a direct impact on agriculture and infrastructure development. An evaluation of soil erosion in the Rewa river watershed can be used to plan conservation activities. Modeling provides a quantitative and consistent technique to estimating the quantity of soil loss under various situations. The goal of this research is to estimate average annual soil erosion in the Rewa river watershed in Naitasiri province, Fiji, using a GIS (Geographic Information System) combined with the RUSLE (Revised Universal Soil Loss Equation) model. According to the findings, a maximum annual soil loss occurs near to developing regions and river tributaries in areas with a high risk of erosion. To avoid potential concerns in places prone to moderate to high erosion risk, erosion control and watershed protection measures must be implemented immediately. In this context, the RUSLE model can be used to analyse soil erosion in small watersheds in a quick, cost-effective, and less labor-intensive manner, hence assisting in sustainable development and supporting healthy land use practices.