Evaluating socio-hydrological stress through potential stormwater harvesting sites using multi-criteria analysis in Mumbai, India

Estimating stormwater harvesting (SWH) is a significant characteristic of enhancing regional water obtainability and thereby preserving water resources. The foremost aim of this study was to approximate suitable SWH locations in Mumbai using several physical and geomorphic parameters by employing the Geographical Information System (GIS) based Analytical Hierarchy Process (AHP) method. Several observed and remotely sensed datasets were used to compute SWH after assigning the share of influence at GIS platform. Numerous physical attributes along with geomorphic features are taken into consideration and further reclassified and allocated ranks to produce the SWH map in Mumbai. The study indicates most suitable portion for SWH is associated with northwestern side of Mumbai along with barren land and vegetation cover of around 226 sq. km area. However, highly dense urban areas (182.5 sq. km) in central Mumbai experienced with low suitable SWH zone. Additionally, LULC-wise investigation exhibited that barren and wetlands are the most suitable part for SWH, averaging 62.7 sq.km, however, nearly coastal areas including central Mumbai, and some open urban spaces are also potentially suitable for SWH. Moreover, flood probability-wise SWH site demonstrates maximum suitability near the upper parts of coastal Mumbai (223.3 sq.km), while 82.9 sq.km area witnessed flood possibility. High-resolution Google Earth images were used to overlap the outcome of SWH in Mumbai. Moreover, the SWH sites were further cross-correlated with regional flood susceptibility, which exposed extreme north and northeastern parts of Mumbai and is eventually essential to yield SWH sites to diminish flood hazards and substantial water availability.