Estimation of soil erosion and sediment yield concentrations in Dudhganga watershed of Kashmir Valley using RUSLE & SDR model

A systematic method, incorporating the statistical RUSLE & SDR model, remote sensing and GIS, was used to estimate the annual soil loss and to display spatial distribution of potential erosion risk in Dudhganga watershed. The RUSLE was used in this study in GIS platform based on erosional factors. The spatial and temporal trend of soil erosion in the watershed was obtained by integrating input variables of RUSLE, such as R-factor, K-factor, LS-factor, C-factor and P-factor, into a grid-based GIS method. The estimated rainfall erosivity factor of the watershed ranges from 560.93 to 342.68 MJ mm ha−1 h−1 yr−1 from the year 2000–2020, respectively. The anticipated annual amount of soil loss in the watershed varies in between 6682.37 and 0 t ha−1 yr−1 for the year 2000. Similarly, the values corresponding to annual soil loss increased to 9879.912 t ha−1 yr−1 for the year 2010. Again, in the year 2020 it marked an increase where it recorded the soil loss values of 11,825.98 t ha−1 yr−1 with mean annual soil loss estimates to be 126.89 t ha−1 yr−1, respectively. The findings of the study revealed that the barren land is the main precarious source exposed to the process of soil erosion and has the upper hand in the rate of soil loss and sediment yield. The results of the study divulged that the most affected part of the watershed is the southwestern side where the majority of the area is occupied by barren land, and consequently, the high soil loss in the upper reaches of the watershed exhibits a close correlation to LS and K factor. It has been found in the study that anthropogenic nuisances like rapid deforestation and reckless unplanned urbanization are the principle drivers responsible for the land change systems in the study region. In the long haul, the outcome of these changes will eventually gear up the soil loss activities in the wetland catchments which in turn will lead to the generation of sediment yield and thereby give rise to sedimentation and siltation of waterbodies and, consequently, will affect their overall water holding capacity.