Numerical simulation of seawater intrusion in the lower Seybouse aquifer system, Algeria

Seawater intrusion represents a high risk for the water supply, the agriculture and industry activities in the lower Seybouse region of North-Eastern Algeria. In order to analyze this risk, a three-dimensional model was developed using the MODFLOW and MT3DMS codes to predict seawater intrusion in the coastal aquifer. The application of this model indicates that the groundwater withdrawals result in a continuous decrease of the water level and in an increase of chloride concentration. Moreover, the salt front could progress by 300 to 2500 m in the land. These results show the necessity of adequate measures for the protection of the aquifer. Numerical predictions for 2045, considering an increase of groundwater withdrawals by 20%, show a fairly significant decrease in water levels, up to -6 m with respect to the mean sea level, and an increase of Cl- concentrations up to about 10 km inland.