Identification of Suitable Sites for Rain Water Harvesting Structures based on Water Budgeting using Remote Sensing & GIS Tools on Watershed Basis

Abstract

The need for application of modem approaches like Remote Sensing and GIS techniques has been emphasized for efficient management of water resources (Jha et aI., 2007). In recent years, use of satellite remote sensing data along with GIS and topographical maps has made it easier to establish the base line information on water resource planning. To identify the suitable sites for surface water conservation structures, GIS has been found to be an effective tool using satellite remote sensing data, topographical maps and collateral information (Krishnamurthy et al., 2000). The study on water budgeting was undertaken in order to assess the water deficit /surplus in every sub-watershed of Pingalgarh watershed located in Parbhani district of Maharashtra state (India). Various thematic maps viz., land use /cover, geomorphology, hydrological soil group, slope, Lineament, land capability, soil texture and soil depth were generated using RS and GIS. Drainage line delineation and water bodies mapping were undertaken using satellite images. The data on area of each crop and population in each sub watershed were collected to estimate the total water requirement. Cadastral map for the study area was geo-referenced. The surface runoff potential was estimated using curve number technique. Based on the water deficit in each sub watershed and by integrating the thematic maps of geomorphology, land use, soil texture and land slope by UNION tool in arc GIS, the suitable location of water harvesting structures were decided preferably on the 1st and 2ndorder streams and marked on the satellite image along with its latitude and longitude. Based on the present water deficit in each sub watershed and considering the geomorphology and land use, the water harvesting structures like cement plugs and percolation tanks are suggested for improving the surface and ground water availability.