Groundwater Potential Assessment Using an Integrated AHP-Driven Geospatial Techniques in the High-Altitude Springs of Northwestern Himalaya, India

Abstract

The Himalayas, also known as the “water tower of the world”, acts as a source for a numerous rivers and rivulets. In mountainous region, population is mainly dependent on springs. In the present study, detailed investigations of the springs were done and their water quality was analysed, including all the basic parameters, and the prime objective of this study is to identify the groundwater potential zones. The springs in the study areas doesn’t contain any contaminants in its origin. All the physiochemical parameters, like pH, TDS, EC, Ca²⁺, Mg⁺, Cl⁻, F⁻, SO₄²⁻, NO₃⁻, Na⁺, K⁺, total hardness, and alkalinity, were well within the permissible limit prescribed by BIS 2012 and WHO 2011. The current study shows that Na⁺ is the dominant cation, whereas Cl⁻ are the most dominant anion in springs water. The identification of the recharge zones was done with the help of satellite data using Analytical Hierarchical Process (AHP) by incorporating the seven factors, viz. geomorphology (highly dissected structural hills and valleys), lineament density (very low in study area), lithology, slope gradient (maximum of study area comes within 30–45° slope), soil (dystric cambisols, eutric cambisols, lithosols) change in land use/land cover (LULC), and drainage density (high in study area) of study areas were considered in assessing the groundwater potential recharge zones. Results indicated that the maximum occurrences of the potential recharge zones were observed along the major river and its tributaries in the study area. Study area are categorized into five different groundwater potential recharge zones: very high, high, moderate, low, and very low. About 28%, 33%, 37%, 2%, and 0.4% of the total area 226 km² lie in very high, high, moderate, low, and very low recharge zones, respectively, in Barot valley, while in Thunag valley, 8% of the total area 276 km² lies in very high potential recharge zone and 41% lies in high, 49% in moderate 1.1% in low, and 0.7 in very low groundwater potential recharge zone. Hence, the groundwater recharge potential zone map will help to formulate better groundwater recharge planning by suggesting appropriate recharge structures, like check dams, trenches, ditches, and percolation tanks.