Application of GIS in rainwater harvesting potential regions – Hyderabad case study

Rapid urbanization and population growth in metropolitan regions have led to increased demand for water resources, exerting pressure on existing water supply systems. In this scenario, Rainwater Harvesting (RWH) emerges as a viable solution to alleviate water scarcity by capturing and utilizing rainwater, thereby conserving natural water bodies. In this context, understanding the spatial distribution of RWH potential becomes crucial for implementing the same. This study aims to delineate RWH potential zones within Stormwater Zone 12 of the Greater Hyderabad Municipal Corporation (GHMC) by integrating GIS and remote sensing data along with hydrogeological features. The Analytical Hierarchy Process (AHP) was employed to assign weights to the considered factors and to calculate the correlation matrix, which is followed by Weighted Overlay Analysis (WOA) to formulate the results. In addition to topographic data such as Digital Elevation Model (DEM), Land Use/Land Cover (LULC), soil data, and socio-economic datasets were also integrated into this study. The results of this study categorized the study area into five distinct classes based on RWH capacity, namely ‘Very Low’, ‘Low’, ‘Moderate’, ‘High’ and ‘Very High’. This study revealed that the final outcomes were highly sensitive to changes in the parameters- LULC, DEM and rainfall patterns. The majority of the area was classified into moderate to low categories, with limited instances of very high potential. In urbanized areas, reduced natural infiltration capacity along with increased anthropogenic activities, impede the retention of incoming rainwater, contributing to the scarcity of areas with very high potential.