Delineation of Groundwater Potential Zone in the Jhiku Khola Watershed, Central Nepal

Abstract

In mountainous areas of Nepal, availability of water sources is becoming more crucial because of either climate change or increasing demand. Considering primary characteristics of geological structures including joints, fractures, and fault zones, this research primarily aimed to delineate groundwater potential zones in mountain slopes of Jhiku Khola (River) watershed situated in Kavrepalanchok District, central Nepal, applying remote sensing and GIS guided by Analytical Hierarchy Process (AHP) for multicriteria decision analysis. In order to rank and produce the factor maps for identifying groundwater potential areas, statistics are utilized according to field characteristics of slopes, their aspects, topographic wetness index (TWI), land use, rainfall, drainage density, lineament density, and geology in keeping with their weightage. The groundwater potential map's ROC/AUC curve has an accuracy of 88.3%. The investigated area, i.e. 124.5 km² is classified into low (2.5%), moderate (96%), and high (1.5%) groundwater potential zones, respectively. Thirty-nine percent of eighty-two springs found in surveyed area are located between 1322 and 1594 meters; fifty percent are between 778 and 1050 meters; twelve percent are between 1050 and 1322 meters; and seven percent are between 1594 and 1866 meters above mean sea level, respectively. It emphasizes how essential water availability is in higher-elevation areas.