Sensitivity of groundwater quality to climate explained variability in the areas of Indus Basin of Pakistan

Groundwater is a reliable source of freshwater, which is strongly affected by climate. So, it is imperative to analyse the climate impacts on groundwater quality and quantity to sustain this precious resource. This study investigates the climate explained variability (CEV) and sensitivity of groundwater quality during 2003 to 2018 in Indus Basin of Pakistan. The results indicated that increasing trends in both electrical conductivity (EC) and sodium adsorption ratio (SAR) values were found at most of the sites (wells). The EC and SAR showed poor correlation (negative/positive) with annual temperature, while mixed behaviour was examined with precipitation. However, the mean values of CEV for EC and SAR were examined as 115% and 28% in pre-monsoon, while 38% and 19% in post-monsoon, respectively. Moreover, during pre-monsoon, the groundwater EC showed negative sensitivity to 50% while showed positive sensitivity in 53% of wells during post-monsoon with rise in temperature. The climatic impacts on groundwater quality were also found spatially varied across the study area.