TITLE:
Groundwater Conditions and the Geoenvironmental Impacts of the Recent Development in the South Eastern Part of the Western Desert of Egypt
AUTHORS:
Ahmed Aziz Abdel Moneim, Sameh Zaki, Maghawri Diab
KEYWORDS:
Toshka Project; Groundwater; Aswan High Dam Lake (Nasser Lake); Aquifer Potentiality; Geo-Environmental Impacts
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.4,
March
31,
2014
ABSTRACT: The area
to the southeast of the Western Desert of Egypt has been subjected to
considerable development activities over the last few years. The development
includes the cultivation of about 2260 km2 of the desert lands “the
well-known Toshka Project”. The hydrogeological conditions of the area are
subjected to detailed investigation based upon the construction of the water
table maps, hydrologeologic cross-sections, pumping tests, aquifer geometry,
and recharge-discharge relationship. The study revealed that the Quaternary and
the Nubia sediments are the main water bearing layers in the area. The
Quaternary aquifer is of limited potential and made of mixed sand with clay
deposit ranges in thickness between 5 to 10 m. The Nubia aquifer is the oldest
sedimentary formation and the main groundwater resources in the area. It is
represented by multilayered of sand and silt exists generally under artesian
conditions. It is composed of three water bearing horizons partially separated
by two confining horizons and extends in thickness ranges between 70 and 230
meters. The thickness increases away from the high dam lake. The analysis of
pumping tests of the aquifer indicated that its potentiality is increasing
north of the High Dam Lake (HDL) whereas it decreases in the other direction.
This is due to high hydraulic conductivity and aquifer thickness in the area
northeast of Khor Toshka and at west of Garf Hussein. The hydraulic conductivity
of the aquifer ranges between 12.73 and 0.9 m/day. The review of the changes in
groundwater levels in the area showed that there is a drop in ranges between 1
and 14 meters in the last few years indicating that the extraction from the
groundwater is much more higher that the replacement rate. Also, the analysis
of the fluctuation of water levels of the HDL and the groundwater level
indicated that the influence of water on groundwater level in the area is
observed only at a distance less than 10 km from the lake shore line. Seepage
from the HDL is estimated as 238.13 × 106 m3/year. The
geo-environmental impacts of the development on the surface water and groundwater
in the area are evaluated.