Determining a better water management using a geographical technique-a case study in Egypt

Living in an age of water scarcity makes all countries worry about something as simple as having enough water to grow sufficient food and fiber for their people. Efficient water use is the most economically and environmentally preferable solution, especially when there are signs for expected water drought and increasing competition over limited water supplies. Increased water requirements provide evidence that Egypt is approaching a period of water scarcity. That condition could be projected to have severe constraints on food production and economic development. In this study geographical information system technology is utilized in association with the Simulation of Water Management in the Arab Republic of Egypt (SIWARE) model for simulating a Nile water supply reduction of 25% for one year. The Middle Nile Delta region (about 3,000 km/sup 2/) was discritized into 116 calculation units of average area of 25 km/sup 2/, then simulated using the SIWARE. The irrigation and drainage system networks were segmented into reaches. All the hydrologic, hydraulic, soil, and crop data were given to the SIWARE. Four water management scenarios (describing methods of irrigation and water distribution being used by the Egyptian Ministry of Water Resources and Irrigation and three other alternatives) were simulated using the SIWARE model. The Geographical Interactive Comparative Display Systems (GICDS) of the SIWARE model provided means for distinguishing between the different scenarios geographically. The spatial variability of the four scenarios' results was compared and subtracted graphically using the GICDS. Each water management scenario was evaluated and given an overall score in order to predict the best scenario with the least long-term impacts under such drought conditions. The effectiveness and functionality of the GICDS was presented. The GICDS proved that, under severe drought conditions (25% reduction in the Nile water supply), the actual water management under practice now by the Egyptian Ministry of Water Resources and Irrigation (irrigation water distribution and allocation were based on the average crop water requirements) was the best scenario with the least long-term adverse effects.