Delineation of Groundwater Potential Zones (GWPZ) of Port Blair, Andaman Islands, India, using Multi Influencing Factors (MIF) method and geospatial techniques

Abstract

This study intended to delineate the groundwater potential zones (GWPZ) of Port Blair and its surrounding areas using the Multi Influencing Factor (MIF) method and geospatial techniques. Multiple data such as geology, geomorphology, slope, soil, drainage density, lineament density, rainfall, NDVI, and LULC were considered for delineating GWPZ. Spatially distributed maps/thematic layers of all the factors mentioned above were prepared using remotely sensed data and by using ground data. These thematic layers were allotted weights after referring to previous literature and study and by considering each layer's influence on groundwater. Finally, all the thematic layers were integrated, and overlay analysis was done to produce a map showing the GWPZ of Port Blair and its surrounding areas. The result (map) was categorized into high, medium, and low groundwater potential zones. This study shows that most of Port Blair's areas come under the medium GWPZ (63.4% of the study area), followed by high GWPZ (27% of the study area), and 10.6% of the area comes under low GWPZ. The most important and innovative part of this study is the physical verification of all the results obtained from the remote sensing and GIS techniques. The GWPZ map was compared with existing well discharge data and validated through the ROC curve, and it shows the study has “very good” accuracy. Finally, this study provides an expedient approach to delineate the GWPZ for practicable management and use of groundwater resources of the area to maintain the sustainability of this island.