Identification of erosion-prone areas using modified morphometric prioritization method and sediment production rate: a remote sensing and GIS approach

Watersheds from semiarid zones are sensitive to land degradation processes wherein the morphometric investigation is an important aspect to unwrap the susceptible areas. Hence it is a prerequisite for the assessment of erosional pattern of the watershed. Thus, based on the response to erosional processes, prioritization task has been undertaken for fourteen sub-watersheds from basaltic region of Western Ghats of India. A morphometry-based framework using weighted sum analysis (WSA) coupled with the remote sensing data, field data and topographical maps were generated on geographical information system (GIS) platform to estimate the soil erosion susceptibility. The study also evaluates the performance of this new methodology by considering the sediment production rate (SPR) of these sub-watersheds. The resultant WSA-SPR model has prioritized the study area into high, moderate low and very low categories. The high and moderate priority areas lie in the proximity of outlet, upper elevated and undulating terrain of the watershed. It represents 41.38% of the total area covering SW1, 3, 13 and 14 sub-watersheds. This study proposes a useful tool to define areas for planning the strategies to control soil erosion and promote soil conservation