Appraisal of groundwater recharge in Neelum watershed (Upper Indus Basin) using geospatial water balance technique

Sci Total Environ. 2021 Sep 1:785:147318. doi: 10.1016/j.scitotenv.2021.147318. Epub 2021 Apr 24.

Abstract

Water availability is important for survival of millions of people living in the Himalayan region of Upper Indus Basin and adequate monitoring system is for better water resources management. In the present study, groundwater recharge appraisals in the Neelum watershed (Upper Indus Basin) were investigated by using water balance and geospatial modeling techniques on monthly time-scale climate data from 1989 to 2015. Results demonstrated that on an average out of total annual rainfall (i.e., 2028 mm), about 46% of the rainfall convert to surface runoff and 35% loss to atmosphere via evapo-transpiration (ET), while the remaining 18% contribute to infiltrate the groundwater recharge. Groundwater recharge enhanced during snow-melt from December to March and the rainfall infiltration increased during July and August months. Similarly, the infiltration ranges 106-177 mm from January to March and 45-51 mm from December to July. The groundwater discharge in the form of oozing from the spring occurred during the remaining six months, which ultimately contributed to the baseflow of the stream. Findings from the study revealed variations in groundwater recharge during the years and hence recommended more hydrological studies to predict future changes in climate and land use for sustainable development of freshwater resources in the Upper Indus Basin.

Keywords: Geospatial modeling; Groundwater recharge; Upper Indus basin; Water balance technique; Western Himalayas.