الفهرس 
GEOMORPHOLOGICAL AND GEOLOGICAL ASPECTS
The young alluvial plainsOnly 14 pages are availabe for public view
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Abstract
Wadi El Farigh area is built up of sedimentary rocks belonging to the Tertiary and Quaternary times. They are formed of different rock units composed of sands, gravels and clays. The Lower Miocene rocks are exposed in most of the studied area. The main water bearing formation in the studied area is the Lower Miocene aquifer. The groundwater exists under unconfined conditions. The Lower Miocene aquifer rests unconformably on the basalt sheets of the Oligocene age and the saturated thickness ranges from 110 m to 330 m. The average relative humidity in winter season reaches 64.5 %, while it reaches 59.2 % in summer season. Average wind speed in winter season reaches 3 m/sec, while it reaches 3.4 m/sec in summer season. The amounts of rainfall rate reaches 238.8×106 m3/year. The studied area falls within the Desert Zone. The total of the actual evapotranspiration reaches 133.23 × 106 m3/ year. The soils of the studied area are classified
according to the obtained hydraulic conductivity values into four zones,
moderately slow hydraulic conductivity, moderately rapid hydraulic
conductivity, rapid hydraulic conductivity and, very rapid hydraulic
conductivity. Discharge is evaluated to be about 90.31 × 106 m3 for
the summer season and 57.51 × 106m3 for the winter season with total
amount of 147.82 × 106m3 / year.
The local recharge of the Lower Miocene aquifer takes place through
lateral seepage from the West Nile Delta aquifer in the eastern part and
lateral flow from the Oligocene aquifer in the western part. In
the northern part, local recharge of the Lower Miocene aquifer in
the studied area takes place from lateral leakage from the Pliocene
aquifer, while in the southern part there is no source of recharge.
The groundwater of Lower Miocene aquifer is the main source for
agricultural and domestic purposes in the studied area. However, due to an imbalance of groundwater regime in the lower Miocene aquifer, it was
necessary to carry out a detailed scientific research to protect and manage
the groundwater resources in the studied area quantitatively and
qualitatively. One major target is to prevent the lowering in
the groundwater level which may lead to deterioration in groundwater
quality.
The present study aims to develop groundwater flow model to
manage the groundwater resources in the Lower Miocene aquifer in
the studied area for the year 2013, and to predict the hydrological
situation up to the year 2024 and 2034, as well as to evaluate the water
budget.
The obtained results from the groundwater flow model indicate
that, the hydraulic conductivity varies from 0.1 m/day to 25 m/day,
the transmissivity coefficient varies between 1000 m2/day to 7000 m2/day
and the specific yield varies from 0.011 to 0.32. The total amount of
recharge in this area reaches about 204.57 × 106 m3 / year. It has been shown during the current study that the amount of groundwater extracted
from the Lower Miocene aquifer in the studied area is about
57.07 × 106 m3 / year for the period from April 2013 to April 2014.
Ten years of prediction from April 2014 to April 2024 reveal an expected
DROP in the groundwater level varies from less than 1 meter to 12 meters.
For the same period, a change of the groundwater storage in the Lower
Miocene aquifer in the studied area is predicted to be
7.72 × 106 m3 / year. This means an expected change in the amount of
groundwater storage reaching about 49.35 × 106 m3 as a loss through
the ten years of prediction if the current discharge rate is maintained.
The results of twenty years prediction indicate a change of
the groundwater storage of about 22.59 × 106 m3 / year as a loss with
an amount of groundwater extracted equals 147.8 × 106 m3 / year. This
means an expected change in the amount of groundwater storage
reaching about 79.66 × 106m3 through the twenty years as a loss. A DROP of groundwater levels varies from less than 1 meter to 14 meters through these twenty years from April 2014 to April 2034 was recorded.
Thirteen scenarios were developed using the groundwater flow model, to predict the hydrological situation associated to different exploitation planes. These scenarios are demonstrated in chapter (V) and table (36)
The current study concluded that, in case of an intended preservation of the groundwater aquifer in the area from more groundwater level lowering, it is advised that the discharge in the studied area is not to exceed 98.83 × 106 m3/ year, which is the case in scenario number seven. In this scenario no loss in the groundwater storage in the aquifer is expected.
Since the studied area has some areas which are not yet reclaimed areas especially in the south, and there is a stronge desire from the decision maker to make an agricultural development in these areas,an extension of more wells to be drilled is proposed in fig. (44) with
a restriction that the amount of total discharge in the area is not to exceed
189.81× 106 m3/ year. In this situation, the calculations show
an expected lowering in the groundwater level varies from less than
1 meter to 20 meters in ten years, and varies from less than 1 meter to
24 meters in twenty years.
On the other hand, in case of drilling new wells which are less
distant from each other than it was shown in fig. (44), a new situation is
proposed in fig. (45), with a total discharge expected to be about
289.35 × 106 m3 / year. This trend will lead to a groundwater level
lowering varies from less than 1 meter to about 32 meters in ten years
and varies from less than 1 meter to 40 meters in twenty years. This
situation shows an example of wrong and not advised exploitation plan
for the groundwater resources in the area, where environmental damages
may result from similar destructive strategies. CHAPTER 7
The following recommendations can be implied from the current study:-
1- No more wells to be drilled in the already reclaimed areas of the studied area.
2- Reducing the discharge rate from the operated wells and keeping the constant rate around 35 m3/h for each well.
3- Growing low water - consuming plants.
4- Using the groundwater for the agricultural activities only.
5- In case of new wells to be drilled in the not reclaimed areas, a proper choice for their locality based on scientific studies is proposed.
6- Recalibrating the groundwater flow model periodically every three years.7- Suggesting a mathematical model for salt transportation in the area in order to depict the deterioration in the groundwater quality in the area.