Hydrochemical properties and environmental isotopes of groundwater of the Quaternary ― Pre Quaternary aquifers in El - Arish ― Rafah area, northeast Sinai, Egypt

摘要

Twenty three groundwater samples were collected from El-Arish ― Rafah area to study the quality of the water and identify the origin of recharge processes in the area of study, using hydrochemical techniques and environmental isotopes. The area of study is characterized by the presence of several water-bearing rock types. The mineral species that affect the chemical composition of the examined water points were evaluated using computer code (WATEQF). A great part of samples are saturated with dolomite and some other saturated with calcite. The water quality of the ,vater samples varies from fresh to saline. The stable isotope composition of the collected water points varied in a relatively wide range indicating a presence of different source of recharge in the area. The enrichment of sand dunes samples in isotopic content is either trace back to loss of water by evaporation or due to sea water contribution. The local paleowater plays an important role in recharging the water points especially in the Lower and Upper Cretaceous water samples. Moreover, the rain water reflects a significant contribution in providing the different aquifers in the area of investigation. A decreasing of salinity is recorded with increasing of stable isotope content reflecting the paleowater effects rather than evaporation.