PROBLEMS THREATENING SUSTAINABILITY IN SIWA OASIS AND RECOMMENDATIONS FOR UNDERSTANDING THE SOURCES OF WATER QUALITY DETERIORATION

Abstract

Siwa Oasis has been chosen as the location for the current investigations. Siwa Oasis is an isolated closed depression located in Egypt’s Western desert. It is surrounded by the Mediterranean Sea to the north (about 330 km), to the west by the Libya-Egypt border (70 km) and Cairo to the east (560 km). There are three major activities in Siwa Oasis: that are represented by agriculture (palm tree, olive, fruits and vegetables), industry, (e.g. mineral water bottling and olive oil extraction), and tourism (medical treatment, safaris). The climate of the Western Desert, particularly in Siwa, is generally torrid and arid. The Siwa depression is occupied by Quaternary deposits (aeolian deposits and lakes), Middle Miocene, Upper Cretaceous (sandstone), and Precambrian (basement complex). The groundwater system in Siwa Oasis hastwo main productive aquifers: a Miocene aquifer (fractured limestone) and a Lower Cretaceous aquifer (Nubian Sandstone). Besides, the Quaternary (clay and sand) uppermost layer is water-bearing because of waterlogging. Siwa Oasis is suffering from waterlogging, increasing soil salinity, and deterioration of water quality in the aquifers. This review includes the problems in Siwa Oasis and recommendations for understanding hydrogeological situations and sources of water quality deterioration to avoid waterlogging and soil salinization through integration of flow modeling, geochemistry and isotopic tracers.