Estimation of water harvesting potential for a semiarid area using GIS and remote sensing

Abstract

The present study was aimed to develop a water harvesting strategy in the semiarid area of Rajasthan, India using the geographic information system (GIS). Information on topography and soils had been digitized to form the GIS database. Land cover information was derived from remote sensing satellite data (IRS-1A) in the form of the normalized difference vegetation index (NDVI). Six basins were delineated using a digital elevation model (DEM) and the total acreage in different slope classes was estimated. These maps were used as input to derive a modified Soil Conservation Service (SCS) runoff curve number. The SCS runoff curve number model was applied to estimate the runoff depth for individual storms and summed up to derive the annual runoff potential for each basin. Subsequently, basins for rainwater harvesting were prioritized based on the runoff generation potential, the availability of agricultural land, the suitability for constructing water harvesting structures, etc. The results demonstrate the capability of GIS and its application for water harvesting planning over larger semiarid areas.