Identification of suitable sites for rainwater harvesting using GIS-based multi-criteria approach in Nusa Penida Island, Bali Province, Indonesia

Abstract

The critical step in increasing water availability and land productivity in areas with freshwater scarcity, such as arid and semi-arid, is identifying suitable sites for Rain Water Harvesting (RWH). Identifying RWH suitable sites is site-specific due to a wide variety of a region’s characteristics. Biophysical (slope, soil texture, drainage density, land use), hydrological (runoff potential), and socio-economic (distance to road, distance to river, distance to settlement) parameters of the study area were implemented integrating multi-criteria decision analysis (analytical hierarchy processes) and Geographic Information System (GIS) to evaluate RWH suitable sites in Nusa Penida Island, Indonesia. This study’s parameters and hybrid method were effective tools for identifying RWH suitable sites. The result also indicated that approximately 38% of the Nusa Penida Island is highly suited for RWH. These areas are characterized by dryland farming as the dominant land use, gentle slope, high runoff potential, high drainage density, and moderately fine soil texture. The initial identification of RWH potential sites could be valuable information in completing water conservation programs for several purposes. This study’s approach also contributes to developing a suitable RWH identification methodology, especially for dry regions in Indonesia.