Hydrologic delineation of ground water potential zones using geospatial technique for Keleghai river basin, India

Abstract

In the present paper, various groundwater potential zones for the assessment of groundwater availability in Keleghai river basin have been delineated using remote sensing (RS) and geographic information system (GIS) techniques. Survey of India (SOI) toposheets, field observations and satellite imageries are used to prepare various thematic layers viz. (a) drainage density, (b) geomorphology, (c) lineament density, (d) land use/land cover, (e) soil type, (f) water bodies density, (g) normalized difference vegetation index (NDVI), (h) slope and (i) mean annual rainfall were transformed to raster data using feature to raster converter tool in ArcGIS platform. The thematic maps have been ranked in a scale of 1–9 depending upon their suitability to hold groundwater. The rank of each map has been converted to a probability weight using Bayesian Decision Theory. Similarly, different categories of derived thematic maps were assigned scores in a numeric scale 1–9, depending upon their capability to store and transmit water. These scores were again converted capability values. This capability values $$ (cv_{i} ) $$ were then multiplied with the respective probability weight of each thematic map to arrive at the final weight map. Integration analysis was carried out using overlay-intersect method and a composite groundwater potential map was generated. The composite potential index was obtained by multiplying weightages with rank numbers of each category and summing up the values of all categories. The resultant final map indicates the potentiality of groundwater occurrence in the study area. This map was then classified into five categorise based on the groundwater potential index value. The result depicts the groundwater potential zones in the study area and found to be helpful in better planning and management of groundwater resources.