Unveiling Meghalaya topography: slope length gradient (LS) factor estimation for insightful soil erosion evaluation

Abstract Meghalaya is known for its complex environment due to its hilly terrain and heavy rains, which result in significant soil erosion challenges. The LS factor is the primary factor used to estimate soil loss. Acquiring accurate LS values has always been a significant challenge. The main aim of this research is to compute the LS factor in the Meghalaya region. Three methods are used to calculate the LS factor: (1) Wischmeier and Smith’s (1978) method, (2) Moore and Wilson’s (1992) method, and (3) Desmet and Gover’s (1996) method. All three approaches used the digital elevation model (DEM) in the spatial domain to determine the LS factor. The results of this investigation demonstrated significant variation in LS factor in all three methods. Wischmeier and Smith’s method yielded LS factor values ranging from 0 to 266.538, Moore and Wilson’s method resulted in values ranging from 0 to 112.631, and Desmet and Gover’s method resulted in values ranging from 0 to 683.679. This study concluded that Wischmeier and Smith’s method resulted in LS factor values distributed uniformly across the spatial domain. In contrast, Moore and Wilson’s method only yielded high values along the flow path and low values in other areas. Additionally, Desmet and Gover’s method identified high LS factors in regions with steep slopes near rivers and streamlines. This study can be helpful in anticipating soil erosion well before time and also in developing a slope management plan in the study region.