Morphometric analysis for prioritizing sub-watersheds and management planning and practices in the north-eastern frontier Himalayan ranges of India

Soil erosion is a serious concern as it has serious impact on socioeconomics, environment and agricultural production system. Northeast India is more prone to soil erosion and resulted in land degradation due to its undulating and rocky terrain, high rainfall, deforestation, overgrazing and jhum cultivation. Information on drainage morphometry along with land use land cover (LULC) are essential aspects of watershed prioritization for soil erosion control due to water as well as their conservation. The present study intends to assess the soil erosion potential of north-eastern frontier himalayan ranges (Mahadevpur block, Namsai district, Arunachal Pradesh) of north-east India by analyzing different morphometry parameters along with existing land use land cover using multi-criteria analysis method. A total of 8 sub-watersheds (SW1 to SW8) were identified in the Mahadevpur block using digital elevation model (DEM) and geographic information system (GIS) tools. Morphometric parameters affecting soil erosion along with LULC were used as criteria of ranking and compound values were obtained for final prioritization. Based on morphometric analysis, SW-1 falls under very high priority group, whereas based on land cover SW-1 and SW-8 falls under high priority group. However, multi-criteria analysis combining both morphometry and LULC, suggest that the SW-1 was falling under very high priority group while SW-4 and SW-6 were classified under low priority. Planners and policy makers in order to develop integrated watershed management plan for socio-economic and environmental sustainability of the area can use the reported information.