التركيب الهيدروكيمياءي للمياه الجوفية في اريحا
محمد رشدي محمد الجندي
Mohammad Rushdi Mohammad Al-Jundi
During the last two years 30 groundwater samples were collected from Jericho in addition of 37 surface water samples were collected from flood water of Wadi AlQuilt and five samples from its channel, Chloride content of floodwater collected during the rainy months of 2003 has an average of 37.05 mg/L and the Na/Cl ratio is 0.83 which is close to the ratio in the rainwater. The SO4-2 and the NO3- concentrations are less than 1.0 mg/L. A small increase in Ca+2 contents with an increase in HCO3 - was noticed during the flood took place during March 2003 which indicate a relative long duration time of water in the soil horizon. The Ca+2 , Mg+2 content are parallel to each other indicating that they are originated from the same source which is carbonate rocks, while the Ca+2 is higher than Mg+2 that is related to the dominant of Limestone in the rock than dolomite. The Na/Cl ratio in all surface water samples is less than the ratio of Na/Cl in wastewater in the region which is 1, and closed to the ratio of rainwater 0.86, meaning that the influent of human activity in the catchments area is limited. The groundwater mixing interpretation shows that there is a high percentage of surface water infiltration into the groundwater reservoir and the ratios from surface water input to the groundwater ranging between 70 % up to 100 % in the western part of Jericho area and decreases eastward and far away from Wadi Al-Quilt and reach 20 % - 10 %, this conclusion conceder by the chemical results of the ground water samples, which show a low content of chloride 260 mg/L in the western part, and increased to 1700 mg/L in the eastern part, in the same direction the electrical conductivity ranging from 1400 s/cm up to 6800 s/cm toward the east, Na + ,Ca+2 concentration increasing from 140 mg/L up to 940 mg/L, 65 mg/L up to 200 mg/L respectively in the east. In the other hand the tritium content rebut this theoretical mixing due to the high content of tritium in the groundwater samples which is parallel to the increasing of salinity toward the east, this mean the traveling time of the flooding water is very short but enough to dissolute the minerals of the Lisan formation as a result the groundwater quality is degraded, and utilized the use of the available water for both domestic and agricultural activities.
الدراسات البيئية , Environmental Studies