GIS-based analytical analysis for selecting potential runoff harvesting sites: the case study of Amman-Zarqa Basin

The objective of this study is selecting the optimized locations for rainwater harvesting using geographic information systems (GIS). The selected study area locates in the northwest of Jordan. It is a catchment area that has two major cities in Jordan with a variation in the landcover. According to our previous studies, six main factors were chosen in order to evaluate the potential as follows: rainfall, soil, land use/land cover, slope, lithology, and drainage density. However, secondary factors were also be considered which are socio-geo-economic factors as follows: wadis, roads, faults, well, and urban areas. The approach that we used depends on the integration between GIS and remote sensing. All the spatial that are produced by GIS and remote sensing were analytically modelled by using the weighted linear combination method. Accordingly, three potential areas were selected for rainwater harvesting. However, the study area was classified into five classes based on the suitability for rainwater harvesting, not suitable areas 2388 km² (63.11%), low suitability 1.1 km² (0.029%), medium suitability 538.03 km² (14.22%), high suitability 843.62 km² (22.29%) and very high suitability 12.63 km² (0.33%). Moreover, three potential sites for establishing rainwater harvesting projects were identified on the final rainwater harvesting suitability map. The study recommends the use of evaporation reduction techniques such as shade balls or floating covers to reduce the evaporation rates from the harvested rainwater reservoir also to rehabilitate the suggested sites for rainwater harvesting projects to utilize the harvested rainwater and attain an environmental systems restoration.