Hydrochemical facies of groundwater in the Gaza Strip, Palestine

Groundwater in the Gaza Strip is the only source of water for domestic, agricultural and industrial uses. Extensive pumping has caused serious quantitative and qualitative problems in the aquifer. The hydrochemical facies are evaluated using the trilinear diagram for 200 water samples. Groundwater in the north and west is mostly characterized by Ca-Mg-HCO3 facies (alkaline water), and in the south and east by Na-Cl-SO4 facies (saline water). Sand dunes and rainfall are the major factors controlling the distribution of hydrochemical facies. The eastern edge of the sand dune belt is considered the barrier that separates the two major facies. Brackish water flowing from the east is mixed with rainwater which infiltrates through the sand dunes to the aquifer. Other factors, e.g. seawater intrusion and extensive pumping, play a minor role in the distribution of the hydrochemical facies.