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GEO-3: GLOBAL ENVIRONMENT OUTLOOK  
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Irrigated agriculture

Water availability by sub-region in 2000 (1 000 m3 per capita/year)

Map shows water availability measured in terms of 1 000 m3 per capita/ year

Source: compiled from UNDP, UNEP, World Bank and WRI 2000 and United Nations Population Division 2001

Agriculture accounts for more than 70 per cent of freshwater drawn from lakes, rivers and underground sources. Most is used for irrigation which provides about 40 per cent of world food production (CSD 1997a). Over the past 30 years, the area of land under irrigation has increased from less than 200 million ha to more than 270 million ha (FAO 2001). During the same period, global water withdrawals rose from about 2 500 km3 to more than 3 500 km3 (Shiklomanov 1999). Poor management has resulted in the salinization of about 20 per cent of the world's irrigated land, with an additional 1.5 million ha affected annually (CSD 1997a), significantly reducing crop production (WCD 2000). The countries most severely affected are mainly in arid and semi-arid regions.

Response measures have included national action programmes, water policy review and reform, promotion of increased water-use efficiency, and irrigation technology transfer. At the global level, FAO initiated a global information system, AQUASTAT, in 1993 which provides data on the use of water in agriculture (FAO 2001).