Hydrology and Earth System Sciences www.hydrol-earth-syst-sci.net 1027-5606 1607-7938 9 5 2005 10.5194/hess-9-535-2005 http://www.hydrol-earth-syst-sci.net/9/535/2005/ http://www.hydrol-earth-syst-sci.net/9/535/2005/hess-9-535-2005.html http://www.hydrol-earth-syst-sci.net/9/535/2005/hess-9-535-2005.pdf 535 547 2005-11-16 Development and validation of the global map of irrigation areas S. Siebert P. Döll J. Hoogeveen J.-M. Faures K. Frenken S. Feick Institute of Physical Geography, University of Frankfurt, Frankfurt (Main), Germany Food and Agriculture Organization of the United Nations, Rome, Italy A new version of a digital global map of irrigation areas was developed by combining irrigation statistics for 10 825 sub-national statistical units and geo-spatial information on the location and extent of irrigation schemes. The map shows the percentage of each 5 arc minute by 5 arc minute cell that was equipped for irrigation around the year 2000. It is thus an important data set for global studies related to water and land use. This paper describes the data set and the mapping methodology and gives, for the first time, an estimate of the map quality at the scale of countries, world regions and the globe. Two indicators of map quality were developed for this purpose, and the map was compared to irrigated areas as derived from two remote sensing based global land cover inventories.