Soil Erosion Estimation by RUSLE Model Using GIS and Remote Sensing Techniques: A Case Study of the Tertiary Hilly Regions in Bangladesh from 2017 to 2021

Abstract

Abstract Soil erosion is a major type of land degradation in Bangladesh, especially in the tertiary hilly regions that are located at the northeastern and southeastern region of the country. The Revised Universal Soil Loss Equation, combined with Geographic Information System, is a reliable methodology to estimate the potential soil loss in an area. The aim of this research was to use the RUSLE model to estimate the soil erosion in the tertiary hill tracts of Bangladesh from 2017 to 2021. The erosivity factor was determined from the annual average precipitation of the region, and erodibility factor was estimated from the soil database. The elevation model was used to analyze slope length steepness factors, while land use land cover was used to compute cover management factor. Lastly, land use and elevation was integrated to estimate the support practice factor. Results revealed that the potential annual soil loss from the hill tracts was higher in 2021 than 2017. Although, total annual rainfall was high in 2017, soil loss was found higher in 2021 which is an indication of land use changes. This investigation will help the policy makers to identify the erosion vulnerable areas that requires immediate soil conservation practices. However, there is no latest field-based data available for the country which is required to validate the estimated soil loss of the model. Hence, it is recommended to conduct field-based researches for validating the model-derived result, developing soil erosion model, and creating a reliable soil erosion database for the country.