Hydrogeochemical modeling of the shallow groundwater in the northern Jordan Valley

The reasons for the rapid degradation and salination of the shallow aquifer in the northern Jordan Valley were investigated. Shallow groundwater, surface water and thermal water were sampled from the study area for this purpose. The geochemical mass-balance technique was used to quantify the contribution of different sources, geochemical processes and rock types to the final water composition, applying the NETPATH software package. The isotopic compositions of the water were also investigated. The results suggest three potential recharge sources: the Yarmouk River, the Jordan River, and the Mukheibah thermal water. Evaporation significantly contributes to the current chemistry of the shallow water, as is indicated by the geochemical models and the isotopic results. Tritium analyses indicate that the water is clearly new (less than 50 years). The relatively high values of nitrate in some wells may be of anthropogenic origin.