Mapping Groundwater Potential Zones Using Remote Sensing and GIS Techniques in Sainj River Sub-Watershed, Kullu, Himachal Pradesh

Abstract

Ensuring availability of drinking and irrigation water for population living in mountainous environment has been an important challenge for researchers, spatial planners and policy makers. The identification and mapping of groundwater potential zones in such type of regions may prove a better input to meet this challenge. The present study is an attempt to find out the groundwater potential zones using state-of-the-art technologies of Remote Sensing (RS) and Geographic Information System (GIS) selecting a case study area of Sainj river sub-watershed (area 81 km 2 ) in Kullu of Himachal Pradesh, India. Landsat-8 (OLI) satellite data (October 2016, spatial resolution (30 m resolution) Survey of India (SOI) Toposheet (Scale 1:50,000) and GIS software ArcGIS version 10.5 were used to prepare various thematic layers such as Geology, Soil, Geomorphology, Land Use Land Cover (LULC), Slope, Lineament, and Drainage Density. The watershed delineation and contour lines (100 m interval) generation were performed using Digital Elevation Model (DEM). The LULC map was prepared through supervised classification using Support Vector Machine (SVM) method in ENVI 5.0 software. Spatial analyst tool of ArcGIS 10.5 was used to identify groundwater potential zones using weighted overlay method. The study indicates that the spatial variations in groundwater occurrence are largely controlled by geological structures, landforms and slope in the study area. The study also reveals the importance and usefulness of RS and GIS techniques for proper groundwater resource appraisal and mapping groundwater potential zones. The five groundwater potential zones were identified and mapped in the study area viz. very poor (1.1 km2, 1.36%), poor (7.3 km 2 ,9.03%), moderate to good (67.2 km 2 ,83.17%), good (4 km2,4.95%) and very good (1.2 km2,1.49%). The weathered / fractured quartzite, limestone, slate, schist, and phyllite, among other minerals, characterize the zone with very good groundwater potential. While, the granite, car-biotite, met basalt, and granite gneiss are commonly found in the zone, which has a moderate to good (medium) groundwater potential. Low groundwater zone locations are generally underlain by granitoid, gneisses, and migmatite.