الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Summary and Conclusions
The present thesis concerns with detailed geomorphologic,
geologic, hydrogeologic and hydrogeochemical settings of wadi
Qena basin. It also deals with the effective factors on the
development of water resources in the study area. Wadi Qena
basin occupies an area of 15455 Km2 and extends in northeastsouthwest
direction discharging its water in River Nile. It lies
between latitudes 26° 15´ 00” & 28° 15´ 00” North and between
longitudes 32° 15´00” & 33° 30´33”East.
The average annual precipitation over Wadi Qena basin
was extracted from 3-hourly, Tropical Rainfall Measuring
Mission (TRMM), precipitation data over a period of 15 years
(from 1998 to 2013). It decreases from 13.43 mm/y on the eastern
part of the study area to 2.78 mm/y on the western parts.
Geomorphological features, the study area is divided into
several land features. These features are the high lands (watershed
areas) and low lands (water collectors). The first includes; the Red
Sea mountainous terrains, the high plateaus (El Maaza limestone
and El Ababda sandstone), the low plateau and hilly area. The low
lands include the morphotectonic depressions, piedmont plain and
drainage networks. The general characteristics and
hydrogeological significance of these units are explained. Wadi
Qena main basin and its tributaries are morphometrically
analyzed. Assessment of the flood strength and hazard degrees of
the studied sub-basins relative to each other is also calculated.
Geologic setting:
Stratigraphic succession, in the present study, special
attention has been paid to the stratigraphic setting of the water
bearing formations especially Nubia sandstone and Quaternary
deposits where both of them represents the main aquifers in the
study area. The lithologic sequence and rock exposures along
Wadi Qena basin range in age from Precambrian to Quaternary.
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The stratigraphic succession (250 m thick) at Qena-Safaga road
was measured and sampled.
The petrographic studies, twenty-five samples have been
petrographically examined. Based on Pettijohn’s classification
(1972), four microfacies associations have been defined,
described and illustrated. These microfacies are Quartz arenite
represents 52% of the studied samples, Sub-litharenite represents
32%, Quartz wacke represents 8% and Pebbly Quartz wacke
represents 8% from the studied samples. Compaction and
cementation are the most common diagenetic process that
detected in the studied sandstone samples of the Nubia Formation.
Generally, the studied sandstone thin sections have well
developed intergranular porosity in most studied samples ranging
between 10-21%. The pores are interconnected giving good
permeability favorable for development of good groundwater
aquifers in the studied area
Structural settings, Wadi Qena basin was intensively
affected by structural discontinuities, i.e. shear zones, faults, folds
and fractures. Two prominent shear zones were reported in the
study area including: Qena-Safaga shear zone and the Najd shear
system.
Landsat TM ratio images (e.g. 5/7, 5/1 and 5/43/4 in
RGB) were created Delineating surface structural features. Based
on interpretation of these Landsat ratio mosaic together with
geologic maps and field investigation, three major zone belts of
Najd shear zone were mapped (NJ1, NJ2 and NJ3). While, The
Qena-Safaga shear zone was mapped on the basis of its NE-SW
trend and right-lateral displacement.
Mapping subsurface structures is based on separation of the
total intensity magnetic map into its regional and residual
components. This was conducted using the fast Fourier transform
technique in the Oasis Montaj TM package (version 7.1, 2010).
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142
The major structural trends in the study area includes the NE-SW
(Qena-Safaga trend) and the NW-SE trends (Najd shear system).
Locations of the inferred basins and uplifts are consistent with the
borehole data obtained from deep wells drilled along N-S traverse
in the study area.
The structural features (e.g. shear zones and faults) in Wadi
Qena basin indicates a striking similarity in the trends of surface
and subsurface structures. Spatial analysis of these structures
indicate that the surface shear zones and faults extend deeply
through the subsurface succession and could be interpreted as a
reactivation of the pre-existing structural weaknesses in the
basement rocks during the Red Sea opening.
Hydrogeological conditions: The groundwater in Wadi
Qena basin is available from different water bearing formations
under different hydrogeologic conditions. The water bearing
formations are (from the younger to the older):
The Alluvium Quaternary Aquifer, is formed of sand,
gravel, and boulders filling the courses of the hydrographic
basins. They vary laterally and vertically in the lithological
composition and thickness according to the dominated rock
exposures. The thickness of these deposits generally increases
toward the River Nile Valley, where the thickness exceeds 100 m.
Its groundwater is characterized by unconfined conditions where
the depth to water ranges from 2.7m to 35.95 m. The total
dissolved solids (TDS) value varies greatly between 586.71 mg/l
to 36507.38 mg/l due to the circulation of irrigation water.
The Carbonate and Sandstone aquifer (Eocene-Pliocene),
is formed of undifferentiated sandstone and carbonate rocks of
Eocene-Pliocene age. The water in this aquifer occurs under free
water table where the depth to water ranges between 25 m to 65 m
from the ground surface. Locally, the aquifer is bounded with clay
layers (wells no. 27and 44). So, the groundwater exists under
semiconfined to confined condition in these two wells. The total
dissolved solids range between 2275 mg/l to 11401.45 mg/l, the
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143
variation in salinity values is attributed to the lithologic
composition of water bearing formation.
The Nubia Sandstone Aquifer (Turonian-Santonian):
consists of sandstones and gravels with shale intercalations and it
has 200m thick. The groundwater in this aquifer occurs under
confined condition where it is overlain by the impervious Quseir
variegated shale. The groundwater flow in this aquifer is from the
northeast to southwest. The water salinity ranges between 1300
mg/l to 2251mg/l. The low salinity value is attributed to the
closeness of wells from a watershed area and mixing with surface
water or other shallow aquifers. On the other hand, high salinity
value is due to the leaching processes and the stagnancy of the
water. Upward leakage of the groundwater of this aquifer through
Deep seated faults occurs and recharges the shallow Post Nubia
and Quaternary aquifers.
The Fractured basement aquifer (Precambrian), occupies
the eastern portion of Wadi Qena basin and represented by the
Red Sea Mountains. They are highly weathered and fractured.
Most of the water points were detected in areas where
extensive drainage network intersected by long and thick dykes.
Thirteen water points tapped this aquifer which is mainly formed
of granite. The groundwater in this aquifer occurs under
unconfined condition. The TDS in this aquifer range between 504
mg/l to1801 mg/l.
Hydrogeochemical characteristics: The Hydrogeochemical
aspects of the groundwater in the study area were discussed
through the following topics; groundwater salinity (TDS), major
ions concentration, hypothetical salts combinations,
hydrochemical coefficients (ion ratios), geochemical
classification of the groundwater, evaluation of groundwater
quality and stable isotopes.
The salt assemblages in the groundwater of the different
water bearing formations are calculated. They reflect different
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144
controlling factors (e.g. the effect of leaching and dissolution
processes with the aquifer matrix)
The geochemical classification of groundwater samples
shows that most of the Quaternary, Post Nubia and Nubia aquifers
exhibit secondary salinity properties. On the other hand, most of
the groundwater samples of the fractured basement aquifer refer
to primary alkalinity.
Thirty-six groundwater samples were analyzed for isotopic
compositions (O, H). The investigated samples were classified
into two end members, one mixed group and one mixed with
evaporation group. The groundwater samples collected from the
Quaternary and Post-Nubia aquifers show a strong mixing
signature between the deep, highly depleted Nubia waters and the
modern meteoric waters. These samples are located proximal to
deep-seated faults which act as vertical conduits along which
groundwater upward leakage from the deep Nubia sandstone
occur and recharge the overlying Post-Nubia and Quaternary
aquifers. Furthermore, some of these samples show deviation
from the mixing line between meteoric and Nubia waters
indicating that the modern meteoric waters were subjected to high
evaporation prior to infiltration. On the other hand, samples
tapping the Nubia sandstone aquifer (NAS) in the northern part of
the study area (i.e. near the outlet of Wadi Fattera sub-basin) show
a strong mixing between Nubia and meteoric waters (without
evaporation). The mixing ratio ranges from 28 % meteoric waters
to 36%.
The hydrogeologic evaluation of the study area reveals that
the best sites for groundwater extractions in Wadi Qena basin
should be around the delineated deep-seated faults. Future plans
for land reclamation in the Egyptian deserts (96% of the total area
of Egypt) should take into consideration the role of structure
control (e.g. shear zones, faults and fractures) on the groundwater
flow and accumulation. The integration of remote sensing data
sets, with geophysical, stable isotopes, field and GIS technologies
is effective in improving our understanding of the role of
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145
structural control and modern recharge in exploration for aquifer
potential in arid environments and could be applicable for similar
regions worldwide