Delineation of potential groundwater recharge zones in the coastal area of north-eastern India using geoinformatics

Abstract

Integration of satellite-based remote-sensing data and the geographical information system (GIS) for the exploration of groundwater resources has developed a revolution in the field of groundwater research, which assists in evaluating, observing, and preserving groundwater resources. In the present paper, various groundwater potential zones for the assessment of groundwater recharge zone availability have been delineated using remote-sensing and GIS techniques. Landsat 8 satellite imageries were used to prepare various thematic layers such as: lithology, altitude, slope, and groundwater table map from the inventoried tube well data. These layers were then transformed into raster data using the feature to raster converter tool in the ArcGIS 9.3 software. The raster maps of these factors are allocated a fixed score and weight computed from multi-influencing factor (MIF) technique. Subjective weights are assigned to the respective thematic layers and overlaid in GIS platform for the identification of potential groundwater recharge zones within the study area using weighted overlay index analysis (WOIA). The groundwater potential zones thus obtained were divided into five categories, viz., very poor, poor, good, moderate, and excellent zones. The results reveal that the areas of excellent groundwater potential are estimated to permit precipitated water percolates into subsurface and ultimately contributes to recharge the groundwater. These results suggest that the high potential zones will have a key role in future expansion of drinking water and irrigation development in the study area.