140
over the last decade from the use of relatively simple global models, consisting of
atmospheric models coupled to slab ocean models (IPCC 1990a, b), to more realistic global coupled ocean-atmosphere-land-ice models (IPCC 1999).
Uncertainty in future climate change presents a key challenge for water resources
adaptation planning. Uncertainty in climate information form limitations in our
ability to model the climate system and in our understanding of how future greenhouse gas emissions will change (Moss et al. 2010). Climate projections are based
on a variety of scenarios, models and simulations procedures, which contain a number of embedded assumptions. Gagnon-Lebrun and Agrawala (2006) noted that the
level of certainty associated with climate change and impact projections is a key in
determining the extent to which such information can be used to formulate appropriate adaptation responses.
The objective of this chapter is to review all the previous climate change studies
done in Egypt on water resources, crops production, evapotranspiration, seasonal
crop coefficients, water consumptive use and water requirements of crops, cultivated soils and areas, suitability of growing area to be cultivated with a certain crop
and food gaps in Egypt.
7.2 Climate Change and Water Resources
Egypt is enormously relays on the Nile River as a main source of water resources,
which contributes with about 95% of Egypt’s water budget. Other sources are precipitation and groundwater, which contribute with about 5% of the available supply.
Hulme et al. (1995) indicated that temperature rise by 2 °C coupled with a 20%
decrease in precipitation could reduce the flow of Nile by 88%. Whereas, a higher
increase in temperature to 4 °C with the same reduction in precipitation could result
in 98% decrease in Nile flows. Sayed (2004) indicated that the studies on the effect
of climate change on the Nile flow clearly showed that the assessment is strongly
dependent on the choice of the climate scenario and the underlying GCM model.
For temperature, although the magnitude of the change varies, the direction of
change is clear, where all models expected that a rise in the temperature. For rainfall, however, not only the magnitude varies substantially across the models, but
even the signal of the change varies. The choice of the emission scenario also leads
to different projection. In addition, other studies show that the Nile flow is extremely
sensitive to climate, and especially rainfall changes due to the highly non-linear
relationship between precipitation and runoff. The uncertainty about the increase or
decrease in precipitation near the sources of the Nile, as well as variations in temperature could have a larger than expected effect on Nile flows because these two
factors are also interrelated leads to moderate to extreme effects (Elsaeed 2012). In
addition, Nour El-Din (2013) reported that there are some uncertainty about that the
effect of future climate changes in East Africa, where roughly two-thirds of the
S. Ouda and A. E.-H. Zohry
over the last decade from the use of relatively simple global models, consisting of
atmospheric models coupled to slab ocean models (IPCC 1990a, b), to more realistic global coupled ocean-atmosphere-land-ice models (IPCC 1999).
Uncertainty in future climate change presents a key challenge for water resources
adaptation planning. Uncertainty in climate information form limitations in our
ability to model the climate system and in our understanding of how future greenhouse gas emissions will change (Moss et al. 2010). Climate projections are based
on a variety of scenarios, models and simulations procedures, which contain a number of embedded assumptions. Gagnon-Lebrun and Agrawala (2006) noted that the
level of certainty associated with climate change and impact projections is a key in
determining the extent to which such information can be used to formulate appropriate adaptation responses.
The objective of this chapter is to review all the previous climate change studies
done in Egypt on water resources, crops production, evapotranspiration, seasonal
crop coefficients, water consumptive use and water requirements of crops, cultivated soils and areas, suitability of growing area to be cultivated with a certain crop
and food gaps in Egypt.
7.2 Climate Change and Water Resources
Egypt is enormously relays on the Nile River as a main source of water resources,
which contributes with about 95% of Egypt’s water budget. Other sources are precipitation and groundwater, which contribute with about 5% of the available supply.
Hulme et al. (1995) indicated that temperature rise by 2 °C coupled with a 20%
decrease in precipitation could reduce the flow of Nile by 88%. Whereas, a higher
increase in temperature to 4 °C with the same reduction in precipitation could result
in 98% decrease in Nile flows. Sayed (2004) indicated that the studies on the effect
of climate change on the Nile flow clearly showed that the assessment is strongly
dependent on the choice of the climate scenario and the underlying GCM model.
For temperature, although the magnitude of the change varies, the direction of
change is clear, where all models expected that a rise in the temperature. For rainfall, however, not only the magnitude varies substantially across the models, but
even the signal of the change varies. The choice of the emission scenario also leads
to different projection. In addition, other studies show that the Nile flow is extremely
sensitive to climate, and especially rainfall changes due to the highly non-linear
relationship between precipitation and runoff. The uncertainty about the increase or
decrease in precipitation near the sources of the Nile, as well as variations in temperature could have a larger than expected effect on Nile flows because these two
factors are also interrelated leads to moderate to extreme effects (Elsaeed 2012). In
addition, Nour El-Din (2013) reported that there are some uncertainty about that the
effect of future climate changes in East Africa, where roughly two-thirds of the
S. Ouda and A. E.-H. Zohry