Assessment of seasonal groundwater quality variation employing GIS and statistical approaches in Kabul basin, Afghanistan

Increased demand for groundwater resources, restricted accessibility, and declining quality needs long-term groundwater conservation, particularly in metropolitan areas. The present study aimed to develop the regional spatial distribution of several groundwater quality parameters and assess their seasonal statistical significance in the Kabul basin of Afghanistan. Groundwater quality data of 54 monitoring wells were collected from the National Water Affairs Regulation Authority of Afghanistan, including the dry and wet seasons data. Some particular water quality measures, such as electrical conductivity, total dissolved solids, hardness, nitrate, chloride, fluoride, sulfate, sodium, and some heavy metals, were chosen for the analysis. These parameters' spatial distribution maps and temporal variations were developed to interpret spatial trends in groundwater quality and seasonal variations. Seasonal fluctuations in each quality metric were also tested to see if they were statistically significant. Based on the statistical findings, seasonal changes in the concentrations of magnesium, sodium, chloride, fluoride, iron, and manganese varied significantly. Out of the 20 assessments of water quality, 14 during the dry and 15 during the wet seasons revealed concentrations higher than the World Health Organization recommends. Variations in water quality metrics are correlated to the amount of recharge volume, hydraulic conductivity, and the geological formation of the region. The level of qualitative parameters has increased in the wet season, mainly in the wells located close to river routes or in agricultural areas. Results provide further insights into groundwater quality. Local authorities can utilize the outputs to develop sustainable water resource management.