Identifying Suitable Sites for Rainwater Harvesting Structures Using Runoff Model (SCS-CN), Remote Sensing and GIS Techniques in Upper Kangsabati Watershed, West Bengal, India

The Upper Kangsabati Watershed (UKW) is a drought-prone region where the scarcity of water risk has been leading to the serious potential human problems. To mitigate this water scarcity threat, watershed management in the forms of construction of rainwater harvesting (RWH) structures to trap the rainfall and unused surface runoff has become the main priorities. Watershed has been chosen as one of the principal planning units for water resources management in a sustainable way. The rainfall induced runoff always play vital role of the availability of surface, sub-surface and groundwater recharge within a particular watershed. The aims of our present research work are (a) to estimate the surface rainfall-runoff using Soil Conservation Service Curve Number (SCS-CN) analysis and geospatial (GIS) technology, and (b) to identifying favorable sites for collection of rainwater using guiding principles given by Integrated Mission for Sustainable Development (IMSD) in conjunction with overlay analysis of weighted parameters in GIS platform of UKW. The different environmental parameters i.e. land use land cover (LULC), soil classes (texture), geomorphic, lineament, weathering profile, slope, hydrologic soil group (HSG),rainfall, runoff depth, and stream orders have used to analysis surface runoff and delineating different RWH structures of UKW. However, it has noticed that the deepness of average annual runoff is 979.45 mm and runoff volume is 280.85 m3. Being a part of the Chhotanagpur plateau, the study area is covered with hard rock terrain and having undulating rugged topography; thus, average annual runoff depth is significantly high. In addition, total thirty-three check dams, twenty-eight minor irrigation tanks, and eleven percolation tanks locations have identified for sustainable rainwater harvesting structures. Hence, this study will help planners to conserve the water, land and other natural resources of UKW.