Major ion chemistry of groundwaters in the Continental Terminal water table of southwestern Niger (Africa)

Numerous chemical analyses undertaken during the last 4 a in the Niamey area of the Continental Terminal groundwaters (SW Niger, Africa) reveal large seasonal variations and high NO3 content (up to 2.87 meq/l). The positive correlation between conductivity and depth to the water table indicates that the chemical change is associated with the recharge. In the shallow wells, this highly mineralised recharge reflects the rain composition, variably concentrated by evaporation processes.