APPLICATION OF STABLE ISOTOPES (O-18,D) AND GEOCHEMISTRY TO STUDY GROUNDWATER IN BAHAREYA OASIS, WESTERN DESERT, EGYPT

Bahareya Oasis is one of the five big oasis located in the Western Des ert of Egypt. Seven water samples were collected from the study area. The isotopic composition reflects the paleo-meteoric continental origi n of these waters. Deuterium and oxygen-ii results indicate that the g roundwaters were recharged under cooler climatic conditions much lower than that of the present day Saharian climate. Salinity values range from 170 mg/l to 338 mg/l. The change in chemical water type from NaCl in El-Gedida area to MgSO4 in El-Bawiti area reflects environmental i mpact through leaching of saline soils and infiltration of agricultura l drainage water containing dissolved sulphate salts. The groundwater quality in the area is found to be suitable for agricultural uses.