258
E.-S. E. Omran
longitudes of 27° to 31.5° E. The main objective of this research is to detect the
waterlogging in. Three examples of areas in the desert have been analyzed, Dakhla
Oasis, Kharga Oasis, and Farafa Oasis. Depending on the hydrological, socioeconomic and political, the capacity of the various oases is different. First, Dakhla Oasis
is a relatively large oasis with 350 km from the Nile River. Aquifer extraction has
already had some environmental impact. If the current rate of extraction were raised,
the economic level of 65 meters below ground level would still not be reached. The
groundwater quality in this oasis is generally good, and this means that the agricultural area in this oasis could be increased. Second, Kharga Oasis is located 140 km
east of the Dakhla Oasis. The quality of the water is good but the extraction is already
so high that it has repercussions and the water level has deteriorated as a result. The
third, Farafra Oasis is located 627 km from Cairo and has some natural wells and 140
active wells, and there are good opportunities to expand the agricultural areas east of
Farafra, but it has resulted in environmental dangers and diminishing groundwater
level due to poor placement of wells.
Permanent irrigation requires continuous use of water in the fields, which
contributed to waterlogging after some time. Soil saturated of water causes the
distance between the surface and the groundwater table to be sufficiently small to
allow evaporation to bring water up. The relatively small amount of salt in groundwater can now settle on the surface of the soil, allowing for an increase in soil
salinity over the years. Gradually, salinization impacted the plant and soil. Therefore, a drainage system is needed to prevent crop and land deterioration. There is
more or less no rain in the desert, and there is extremely high evapotranspiration, so
the only source of water comes from groundwater. Furthermore, the costs to provide
the agricultural land with sub-surface drainage, in order to prevent the soil from
waterlogging and to provide the soil with enough nutrition would most defiantly be
enormous.
Five major factors responsible for the waterlogging and salinity issue in Dakhla
Basin are identified. Hardpans are the main causes of the problem of waterlogging
and salinity. The insufficient drainage is the second cause. The third cause is irrigation
systems. Even arising from over-irrigation is the depletion of groundwater quality.
Last but not least, groundwater overpumping is the major contributor to waterlogging
development in Dakhla Basin.
8 Recommendations and Potential for Future
Even though each oasis needs to be seen as an entity, as they all display slight differences in the waterlogged area, salinity and water quality. In these oases, however, the
cultivated area can be extended. The main problem within expanding the oasis may
not be the amount of water, because if there is sufficient money available for high-tech
wells, a large amount of water can be pumped out of NSAS. But a good management
practice must be implemented again in order to use the extracted water sustainably
and prevent waterlogged areas. For example, bad positioning of the wells leads to
E.-S. E. Omran
longitudes of 27° to 31.5° E. The main objective of this research is to detect the
waterlogging in. Three examples of areas in the desert have been analyzed, Dakhla
Oasis, Kharga Oasis, and Farafa Oasis. Depending on the hydrological, socioeconomic and political, the capacity of the various oases is different. First, Dakhla Oasis
is a relatively large oasis with 350 km from the Nile River. Aquifer extraction has
already had some environmental impact. If the current rate of extraction were raised,
the economic level of 65 meters below ground level would still not be reached. The
groundwater quality in this oasis is generally good, and this means that the agricultural area in this oasis could be increased. Second, Kharga Oasis is located 140 km
east of the Dakhla Oasis. The quality of the water is good but the extraction is already
so high that it has repercussions and the water level has deteriorated as a result. The
third, Farafra Oasis is located 627 km from Cairo and has some natural wells and 140
active wells, and there are good opportunities to expand the agricultural areas east of
Farafra, but it has resulted in environmental dangers and diminishing groundwater
level due to poor placement of wells.
Permanent irrigation requires continuous use of water in the fields, which
contributed to waterlogging after some time. Soil saturated of water causes the
distance between the surface and the groundwater table to be sufficiently small to
allow evaporation to bring water up. The relatively small amount of salt in groundwater can now settle on the surface of the soil, allowing for an increase in soil
salinity over the years. Gradually, salinization impacted the plant and soil. Therefore, a drainage system is needed to prevent crop and land deterioration. There is
more or less no rain in the desert, and there is extremely high evapotranspiration, so
the only source of water comes from groundwater. Furthermore, the costs to provide
the agricultural land with sub-surface drainage, in order to prevent the soil from
waterlogging and to provide the soil with enough nutrition would most defiantly be
enormous.
Five major factors responsible for the waterlogging and salinity issue in Dakhla
Basin are identified. Hardpans are the main causes of the problem of waterlogging
and salinity. The insufficient drainage is the second cause. The third cause is irrigation
systems. Even arising from over-irrigation is the depletion of groundwater quality.
Last but not least, groundwater overpumping is the major contributor to waterlogging
development in Dakhla Basin.
8 Recommendations and Potential for Future
Even though each oasis needs to be seen as an entity, as they all display slight differences in the waterlogged area, salinity and water quality. In these oases, however, the
cultivated area can be extended. The main problem within expanding the oasis may
not be the amount of water, because if there is sufficient money available for high-tech
wells, a large amount of water can be pumped out of NSAS. But a good management
practice must be implemented again in order to use the extracted water sustainably
and prevent waterlogged areas. For example, bad positioning of the wells leads to