Food & Climate 

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Case studies in developing countries

Egypt

Agriculture in Egypt is restricted to the fertile lands of the narrow Nile valley from Aswan to Cairo and the flat Nile Delta north of Cairo. Together these areas comprise only three per cent of the country’s land area. Egypt’s entire agricultural water supply comes from irrigation, and this water comes solely from the Nile River.  In 1990, agriculture (crops and livestock) accounted for 17 per cent of Egypt’s gross domestic product.

Problem: The amount of water available for irrigation varies both because of changes in the availability of freshwater and because of competition amongst water users. Crop prices and markets also fluctuate. This case study aims to look at the combined effects of water availability and markets on the adaptability of the agricultural system.

Methods: A physically-based water balance model of the Nile Basin is used to evaluate river runoff and enable inferences to be drawn concerning water supply for agriculture. Process-based agronomic models are then used to estimate crop yields and crop water requirements. Finally, farm based decision support systems are used to look at the economic advantages of different water management options.

Scenarios: Climate is not the only factor which varies from year to year. Population dynamics and changing economic and technological conditions are likely to affect agriculture even more than changes in climate. It is important to take such changes into account in scenario impact assessments.

However, predicting population dynamics and economic conditions are equally, if not more, uncertain than predicting climate. Therefore scenarios need to be designed carefully to address a range of possible conditions. A useful approach is to contrast "optimistic" and "pessimistic" views. A scenario of no change (i.e., present conditions) should also be included. The differential effects of climate management change on current conditions, and on these two alternative scenarios can then be evaluated.

Impacts: An agricultural water productivity index is used to measure impacts on agriculture where total agricultural production in tonnes is divided by total agricultural water use in cubic metres.

The agricultural water productivity index declined by 13 percent when an optimistic view of future change was considered.  It declined by 45 percent when the pessimistic scenario was used.

2. Irrigation alternatives.  Possible adaptation measures for irrigation systems in Egypt.  Many crops are still irrigated by simply spraying water onto the fields and letting it infiltrate into the soils.  These pictures show much more efficient "localised irrigation" where much smaller amounts of water are used very close to each plant.

Adaptive responses: The impacts of adapting water resources by diverting major rivers, more efficient irrigation through improved water delivery systems, changing crop varieties grown and better crop management and coastal protection against sea level rise were all studied.  They achieve a modest seven to eight percent increase in agricultural performance compared to no adaptation, but together would be extremely expensive to implement.  However, investment in improving irrigation efficiency appears to be a robust, ‘no regrets’, policy that would be beneficial whether or not the climate changes.

About this page:

Author:  Marta Moneo and Dr. Ana Iglesias - Universidad Politécnica de Madrid, España
1. scientific reviewer: Alex de Sherbinin - CIESIN, Columbia University, USA
2. scientific reviewer: Lily Parshall - Goddard Institute for Space Studies, Columbia University, USA
educational reviewer: Emilio Sternfeld - Colegio Virgen de Mirasierra - España
last published: 2004-05-12