الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Due to consuming most of the available water by the agricultural sector besides growing demand-supply gap during overpopulation and many other challenges facing Egypt, water scarcity will definitely affect our food security. Accordingly, for Egypt, land and water resources management is considered an absolutely strategic priority. This research introduces future expectations for the availability of water depending on discussion of the available water resources and demand through the different strategies. The decrease in average water expenditure is expected during overpopulation. A linear programming model is offered for optimal cropping pattern in Egypt by maximizing the total net profit. The optimal allocated areas for twenty eight crops are calculated during the period from 2008 - 2012 using the Simplex method with Excel worksheet. Different constraints are incorporated in the model including water availability, land availability in different seasons of the year, self-sufficiency ratios for food security, crop yields and the actual areas of crops under the existing cropping pattern. Considering the available irrigation water, four different scenarios are being analyzed in this approach by changing the upper and lower limits of the crop area constraints. The results showed that ignoring the cultivation of non-strategic crops causes an increase in the total net return more than that in case of taking into account that the non-strategic crops are as equally important as the strategic crops. The scenario of taking the average of the data will not give the same net benefit as using the data of each year if both strategic and non-strategic crops are included. Tomatoes are considered the crucial crop that control the ups and downs of the total net return. Discussing the effect of reducing the available irrigation water to very low limits and how the cropping pattern will change accordingly. There will be a reduction in the gross net benefit and the allocated cultivated area of the crops. Non-strategic crops are to be minimized significantly. Depending on whether to keep the constraints for the allocated areas of strategic crops that satisfy 100% self-sufficiency or to allow them to be reduced, the total net return and the minimum stage of water shortage will be different.