Site Selection for Rainwater Harvesting Using Remote Sensing, GIS and AHP

Abstract

Aims: The research work was carried out to find suitable sites for rainwater harvesting in Dhatarwadi river basin of Amreli district of Gujarat, India using remote sensing and geographic information system along with analytic hierarchy process.
 Place and Duration of Study: This study was carried out at College of Agricultural Engineering and Technology, Junagadh Agricultural University, Junagadh, Gujarat, India.
 Methodology: In present study, suitable sites for runoff water harvesting structures were identified using guidelines of IMSD (1995) and FAO (2003). Five criteria i.e. rainfall, land use/land cover, soil texture, lineament density and slope were selected. Thematic layers of these layers were analysed using overlay process using ArcGIS software and weights for criterias were derived with experts’ opinion using AHP.
 Results: Results obtained were for water harvesting site selection, AHP generated weight for criteria were 36.1%, 20.6%, 18.6 %, 13.1 % and 11.7 % for rainfall, land use/land cover, soil texture, lineament density and slope, respectively. In study area, 66.79 % area found very high suitable, 24.89 % highly suitable, 5.63 % moderately suitable, 0.88 % less suitable and remaining 1.81 % area found not suitable for water harvesting sites. As per suitability and ground truth, 24 check dam sites on scrubland, 52 check dam sites on cropland, 11 check dam sites on the river bed were obtained and 29 farm ponds sites were proposed in the study area. The result indicates that 72.27% of existing RWH sites are in very high suitability and 26.73% located in high suitable whereas only 0.49 % and 0.49 % are in the moderate suitable and not suitable area, respectively.
 Conclusion: To find suitable sites for runoff water harvesting experts can use remote sensing, GIS and AHP in integration for precise work.