Detecting and Controlling the Waterlogging in Dakhla Basin
249
will be given for a future discussion if there is a reasonable expansion of agriculture
within desert areas.
3 Case 1: Kharga Oasis
Kharga Oasis is situated in the central-western desert in the eastern part of Egypt. The
position is 140 km East from Dakhla oasis and 220 km to the South of Assiut City and
it is bounded by longitude 30° 20
and 30° 40
East and latitude 25° 05
and 25° 30
North (Jahin and Gaber 2011). It is the capital oasis of the New Valley Governorate
(Wael et al. 2013), with a population of over 100,000. The climate of the region is
hot during the summer, rainfall is rather sporadic and less than 1 mm per year (Jahin
and Gaber 2011). July is the warmest month that crosses 40 °C in temperature. High
spring winds are common with sandstorms and shifting sand deposits. Groundwater
from the aquifer is used for agriculture in this region. Since 1959, all deep wells
stopped flowing due to the depletion of groundwater sources by shallow irrigation
wells (Jahin and Gaber 2011).
The total dissolved solids in water, in general, are below the threshold of the
WHO. The pH is between 6.53 and 8.00 and should vary between 6.5 and 8.5 (Jahin
and Gaber 2011), and the sodium concentration in groundwater ranges from 20.9
mgL
−1 to 138 mgL
−1 with a 200 mgL
−1 maximum (Jahin and Gaber 2011). It means
the groundwater quality is sufficiently high to be used for agricultural irrigation.
Research has shown that water levels rise to 140 meters by 2060 in the northern and
southern parts of the oasis (Wael et al. 2013). The transmissivity is 509.8 m
2 /day on
average, and the hydraulic conductivity is 2.5 m/day (Bakhbakhi 2002). Studies and
measurements on reliable water levels are necessary, and regulations are required if
the oasis in agriculture continues to be economically efficient.
Kharga’s depression extends from Aswan to Naga Hammadi, and the plateau at
a low level is about 350-400 meters. The lowest average level is between 60 and 80
meters above sea level, and the lowest point is at 2 meters above sea level near the
village of Boulaq. The low distance is about 185 km, varying from 15 to 35 km, but
it is much longer in the far northwest to 80 km.
The north and east edges are wall-shaped and vertical, whereas the low edge is
difficult to recognize in the western sense as there are no simple edges to which
the floor passes from the lower center to disappear under sand pools that can be
considered the upper western edge. The eastern edge is considered the highest and
steepest, rising about 400 meters above the low ground on average but north lower
than the south.
The eastern edge contains calcareous above a shale layer, the calcareous chalk,
the Dakhla shale, the phosphatic layers and finally Nubia’s sandstone. The eastern
edge cut off a large number of valleys, and these valleys pass through the middle of
the Wadis, functioning as their seven natural corridors.
There are long, thin dune chains on the west end from north to south. The highest
agricultural area of Dakhla, followed by the Farafra, and the least cultivated area of
249
will be given for a future discussion if there is a reasonable expansion of agriculture
within desert areas.
3 Case 1: Kharga Oasis
Kharga Oasis is situated in the central-western desert in the eastern part of Egypt. The
position is 140 km East from Dakhla oasis and 220 km to the South of Assiut City and
it is bounded by longitude 30° 20
and 30° 40
East and latitude 25° 05
and 25° 30
North (Jahin and Gaber 2011). It is the capital oasis of the New Valley Governorate
(Wael et al. 2013), with a population of over 100,000. The climate of the region is
hot during the summer, rainfall is rather sporadic and less than 1 mm per year (Jahin
and Gaber 2011). July is the warmest month that crosses 40 °C in temperature. High
spring winds are common with sandstorms and shifting sand deposits. Groundwater
from the aquifer is used for agriculture in this region. Since 1959, all deep wells
stopped flowing due to the depletion of groundwater sources by shallow irrigation
wells (Jahin and Gaber 2011).
The total dissolved solids in water, in general, are below the threshold of the
WHO. The pH is between 6.53 and 8.00 and should vary between 6.5 and 8.5 (Jahin
and Gaber 2011), and the sodium concentration in groundwater ranges from 20.9
mgL
−1 to 138 mgL
−1 with a 200 mgL
−1 maximum (Jahin and Gaber 2011). It means
the groundwater quality is sufficiently high to be used for agricultural irrigation.
Research has shown that water levels rise to 140 meters by 2060 in the northern and
southern parts of the oasis (Wael et al. 2013). The transmissivity is 509.8 m
2 /day on
average, and the hydraulic conductivity is 2.5 m/day (Bakhbakhi 2002). Studies and
measurements on reliable water levels are necessary, and regulations are required if
the oasis in agriculture continues to be economically efficient.
Kharga’s depression extends from Aswan to Naga Hammadi, and the plateau at
a low level is about 350-400 meters. The lowest average level is between 60 and 80
meters above sea level, and the lowest point is at 2 meters above sea level near the
village of Boulaq. The low distance is about 185 km, varying from 15 to 35 km, but
it is much longer in the far northwest to 80 km.
The north and east edges are wall-shaped and vertical, whereas the low edge is
difficult to recognize in the western sense as there are no simple edges to which
the floor passes from the lower center to disappear under sand pools that can be
considered the upper western edge. The eastern edge is considered the highest and
steepest, rising about 400 meters above the low ground on average but north lower
than the south.
The eastern edge contains calcareous above a shale layer, the calcareous chalk,
the Dakhla shale, the phosphatic layers and finally Nubia’s sandstone. The eastern
edge cut off a large number of valleys, and these valleys pass through the middle of
the Wadis, functioning as their seven natural corridors.
There are long, thin dune chains on the west end from north to south. The highest
agricultural area of Dakhla, followed by the Farafra, and the least cultivated area of