Identification of potential spring recharge areas in the Himalayan catchment using the AHP model and stable water isotopes
摘要
Alpine springs are one of the most critical water sources for remote communities and are a source of sustenance for the ecological balance in the fragile Himalayan ecosystems. However, over the past few decades, the attenuation of discharge and drying of many springs have posed a significant threat to the sustenance of millions of marginalized communities. To address the above issue and ensure the long-term sustainability of the Himalayan springs, we used exhaustive fieldwork, hydrogeological investigation and stable water isotopes (δ18O and δ2H) to delineate potential springs recharge areas. The Analytical Hierarchy Process (AHP) was applied to evaluate the groundwater recharge potential by assigning weights to geo-environmental factors and their sub-categories, employing Geographic Information Systems (GIS) for the assessment. The spatial variation of the stable water isotopes (springs and precipitation) indicates that most of the springs get recharged between the altitudes of 1750 and 2875 masl, similar to the results of AHP. The potential areas of spring recharge were further studied to identify suitable mechanisms for enhancing recharge. Based on physiography and LULC, the area was found suitable for recharge structures like gully plugging, check dams, contour trenches, and basin ponds. The research aims to guide sustainable water resource management strategies that promote the revival and rejuvenation of springs in Himalayan catchments.