ANALYTICAL HIERARCHY PROCESS FOR IDENTIFICATION OF SUITABLE WATER HARVESTING SITE IN GEOSPATIAL ENVIRONMENT
Water is the prime requirement for agriculture, domestic uses and industrial production. In India the per capita available of water is decreasing at a higher rate due to impact of climate change and ever-increasing population. Rainwater harvesting is the technique which is being used in effective storing of surface runoff. There are various types of water harvesting structures namely check dam, farm pond, percolation tank, etc. However, identification of potential site for the construction of the particular water harvesting structure is bit difficult as it depends upon numerous parameters such as soil type, slope, water availability, land use and land cover of the site and the surrounding, etc. The guidelines such as Food and Agriculture Organization; Integrated Mission for Sustainable Development are available for selecting suitable site for water harvesting structures. As the site suitability analysis involves multiple parameters for decision making, in the present study, the selection of suitable site for check dam is made through analytical hierarchy process (AHP) in geospatial domain for Hatni watershed, Madhya Pradesh, India. As location for check dam construction is influenced by soil texture, slope of the terrain, land use land cover, stream order and water availability; these parameters were derived from remote sensing data and analysed. The slope and stream network layers were generated from the digital elevation model (DEM). Further, the influence of soil and water availability in identifying the suitable sites was studied through soil texture and curve number. Different parameters influence the site suitability analysis, therefore, in the present study, IMSD guidelines were used to assign weights to each parameter under consideration. The layers were assigned weights by AHP technique based on pairwise comparison. The layers were reclassified according to the weights, then overlay analysis has been done to get the final site suitability map. As remote sensing provides the synoptic coverage of the earth, it has been further utilised to study the impact of water harvesting structure on its surrounding. The land use land cover map of before and after the construction of water harvesting structure was analysed for change in vegetation condition. It was observed that the vegetative cover has increased after implementation of the water conservation measures. It may be concluded that the geospatial technology has immense potential in site suitability studies for water harvesting structures.