ASSESSMENT OF RENEWABLE GROUNDWATER RESOURCES IN THE ASSIUTY HYDROLOGIC SYSTEM OF THE EASTERN DESERT, EGYPT

Exploring renewable groundwater resources is critical to the future of sustainable agriculture development in the eastern desert of Egypt. To identify and quantify renewable groundwater resources, the hydrologic systems of the eastern desert are being studied in a new research program that began in 2003; the effort is supported by the United Nations Development Program and the Global Environmental Facility International Water Program.

The Assiuty hydrologic system is an important, complex system in the eastern desert, where water demand is high because of progressive, ongoing agricultural development. Previous studies of the Assiuty watershed and our current investigation of groundwater isotopic and geochemical affinities indicate two possible water sources for the shallow groundwater aquifer being investigated: (1) surface water infiltration from runoff caused by sporadic precipitation and (2) upward discharge of deep groundwater from the Nubian aquifer through sub-vertical faults near, and sub-parallel to, the Nile River graben. In this study, we developed an Assiuty shallow groundwater flow model with constrains on hydrologic properties based on data from 77 wells, calibrated with 19 water level measurements. The results simulated with the final calibrated model suggest that 77% of groundwater in the Assiuty shallow system is replenished from the deep Nubian aquifer via faults, with 23% or less coming from surface water runoff. Scenarios of future water usage were simulated with the calibrated model and evaluated for sustainable management.