DELINEATION OF GROUNDWATER, DROUGHT AND FLOOD POTENTIAL ZONE USING WEIGHTED INDEX OVERLAY ANALYSIS AND GIS FOR DISTRICT PATNA, BIHAR, INDIA

Abstract

The geographical information system (GIS) has a broad range of applications for groundwater assessment, delineation, discovery, and resource management of drought and flood zones. The present project is the first effort to delineate the possible region for groundwater, drought and flood using a particular methodology. This study seeks a way to define the potential zone for groundwater, drought and flood for the district of Patna in Bihar state. For the study area, various thematic layers were prepared, such as digital elevation map (DEM), geomorphology, land use and land cover (LULC), soil, drainage density, precipitation, and slope. In order to construct the final groundwater, drought and flood potential zonation chart, the thematic layers were combined using the WIOA technique. The possible areas for groundwater have been demarcated into four zones: 1-poor, 2-moderate, 3-good and 4-very good. In the eastern parts of the district, very strong (GWPZs) were found, while in the west and mid regions, moderate and bad categories were found. Drought and flood potential danger areas were divided into four zones: 1-no risk, 2-low risk, 3-moderate risk and 4-high risk, respectively. In the middle part of the region, there was a higher risk of drought and a reduced risk of flooding in the eastern part of the area, an elevated risk of flooding in the eastern part of the area and a lower to no risk of flooding in the western and central regions. Utilizing well discharge data from 2013, the GWPZ map was validated using groundwater fluctuation statistics for pre- and post-monsoon periods. The groundwater, drought and flood potential zonation map built in the present study will be useful for scholars, scientists, implementers in exploring appropriate water exploration locations and implementing resource utilization.