Hydrochemical Evaluation of Groundwater in Azraq Basin, Jordan Using Environmental Isotopes and GIS

The stable isotopic and chemical composition of precipitation and groundwater of three aquifer systems were studied in the Azraq basin in Jordan. The basin is located in the north-east of Jordan and is considered an important source of fresh water for domestic supply, agriculture, and salt industry. Quantity and quality of groundwater has been deteriorating for the last two decades at various well field locations due to over-pumping and return flow of agricultural water. The water level of the Upper aquifer has declined several meters beyond the initial static water levels and there is no sign of replenishment. The groundwater level has declined on a yearly basis since the 1980s, which caused the major springs in 1990 to cease completely. The isotopic composition of groundwater clustered into three different groups associated with the Upper, Middle, and Deep aquifers respectively. The recharge origins of the first two groups are originating from an area with an elevation much higher than the terrain elevation of the Azraq rainfall station. The recharge origin of the Middle aquifer is higher that the elevation of the Upper aquifer and originate