Assessment of Land Degradation Hotspots in Upper Savitri River Sub-Basin, Raigad District, India Using Geospatial Techniques and Analytic Hierarchy Process

Due to rapid industrialization and physiography of the western ghat especially the region come into Maharashtra has faces land degradation problem. For understand the reasons of land degradation, Upper Savitri River area has been considered for the present work. Upper Savitri River is one of the main tributaries of Savitri River which originates in the eastern part of Poladpur Taluka (administrative boundary) of Raigad District, Maharashtra, India near the Sahyadri mountain. For this study, remote sensing, geographical information system (GIS) techniques and Analytic Hierarchy Process (AHP) modeling have adapted. For this work total nine thematic layers are considered viz., geology, drainage density, aspect, slope, geomorphology, soil depth, rainfall, normalized difference vegetation index (NDVI) and land use land cover (LULC) have carried out. For study the normalized weight of each of this thematic layer, AHP modeling which is based on comparative matrix have been used. The results indicate that, rainfall and slope have the highest impact, accounting for 53% of the overall weightage. The land cover pattern and soil texture in this region, also point that a significant impact on lad degradation, contributing to 26% of the weightage. The remaining criteria collectively had a weightage of 22% in the analysis. Based on the intensity of land degradation and the extent of its impact, the Upper Savitri River area have classified into four categories i.e. very high, high, moderate and low vulnerability. Approximately 5.90% with 21.43 km2 of the area is categorized as being under very high vulnerability, while around 74.59% with 271.04 km2 is highly. Additionally, about 19.47% with 70.74 km2 of the area is moderately vulnerable, and 0.04% with 0.14 km2 is classified as low vulnerability. The research finding shows that the degradation of the land has mainly due to the intensity of rainfall in the region. These findings indicate that there is a pressing need to take measures to prevent further land degradation in the region. Keywords: Analytic Hierarchy Process, Geospatial Techniques, Land Degradation, Savitri River Basin