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The increasing scarcity of water in dry areas is now a well-recognized problem. According to the World Commission on Environment and Development, approximately 80 countries with 40% of the world population already suffer from serious water shortages.

At present, water shortages have led most of and and semi-arid countries to increase food imports because the local agricultural sector is not able to produce sufficient food to fill the existing food gaps. The increasing food gaps are posing serious challenges beyond the economic and political capacity required for the necessary adjustments concerning the allocation and use of water in all sectors, particularly agriculture.

The agricultural sector is by far the largest user of water in the world. On a consumptive use basis, 80-90% of all the water is consumed in agriculture. Unfortunately, water use efficiency in this sector is very poor not exceeding 45% with more than 50% water losses; thereby, enormous water saving could be achieved in the agricultural sector comparable with other sectoral water uses.

The growing water scarcity and the misuse and management of the available water resources are nowadays major threats to sustainable development for the various sectors, especially domestic, industrial and agricultural.

Today, in most countries suffering water shortages, at the heart is the question of whether a water crisis can be averted or whether water can be made productive. Increasing the productivity of water is central to producing food, to fighting poverty, to reducing competition for water and to ensuring that there is enough water for nature. The more we produce with less water and/or with the same amount of water, the less the need for infrastructure development, the fewer the conflicts among the sectoral water uses, the greater the local food security and the more water for agricultural, household and industrial uses, and the more that remains in nature. However, to achieve such goals, major improvements are still required in water resource use and irrigation technology and management. Meeting such challenges will require a far greater effort and significant changes in how water is managed. What needs to be changed? What are the improvements required to cope with increased water scarcity?

These are the issues to be discussed in this paper: addressing the appropriate techniques and proper tools to be adopted for increasing the productivity of water through water saving, and improving the rates in water use efficiency in the irrigation sector coupled with better management systems for water conveyance, allocation and distribution. Copyright (C) 2003 John Wiley Sons, Ltd.