Groundwater Assessment in Sweihan Region, the Northeast United Arab Emirates
Sweihan is located at the northeast of Abu Dhabi Emirate, the United Arab Emirates. Sweihan landscape is sand dune ridges, which could reach a maximum width of 2km, and a height of 30 meters, whereas the agricultural fields concentrated in the interdune spaces. Groundwater in Sweihan area is characterized by low recharge amounts, which is being used mainly for irrigation purpose. The intensive agricultural activities in the study area caused depletion and contamination of the ground water due to heavy uses of organic and chemical fertilizers, as well as heavy pumping. The hydrochemical analysis of 27 samples of groundwater from the study area indicated that the groundwater is characterized by high salinity (high TDS and EC), and high concentrations of chromium, lead, and strontium. Thus, the area of the study is not suitable to be utilized for domestic uses. Groundwater samples were evaluated for agricultural uses by calculation SAR, TH, Na percentage, mar. By using these parameters, groundwater of the study area was found to be unsuitable for agricultural purposes. Two water geneses have originated, the first is paleo-marine water origin of Magnesium chloride water type, which indicated over pumping of deep water where old marine deposits was existed. The second is meteoric water origin of sodium Sulphate-water type indicating an occurrence of infiltration of rainfall and ion exchange processes. The analysis showed that the dominance of sodium and chloride in the area due to agricultural effluents, gives good reasoning of high salinity in the studied area. Isotopes analysis of hydrogen and oxygen of fifteen groundwater samples emphasized that the study area has high evaporation rates, which affects the ground water quality.