Groundwater-surface water interaction along river Kali, near Aligarh, India

River Kali, in the western gangetic plains, is posing serious threat to riparian communities by contaminating shallow riparian zone groundwater. To manage groundwater contamination, this study attempts to investigate the nature of groundwater-river water interaction, during February to April 2018, along a segment of river Kali near Aligarh in western Uttar Pradesh, India. River discharge was measured at three locations in two phases. Hydraulic heads in mini-piezometers were observed twice weekly. Forty water samples were analysed for major ions, nitrate, fluoride, TDS, pH, EC. River discharges and river bank vertical hydraulic gradients reveal that river Kali is losing water to riparian aquifers. Hydro-chemical analysis shows discordance in the pattern of ionic concentrations of river and groundwater, a distinct clustering of river and groundwater for both sampling periods. Ionic concentrations in groundwater with distance from channel indicate potentially clogged riverbed conditions that reduce the interaction of river water with riparian groundwater.