05 Irrigation in Africa, Europe and Latin America Update of the Digital Global Map of Irrigation Areas to Version 4 DOCUMENTATION Stefan Siebert • Jippe Hoogeveen • Karen Frenken Frankfurt Hydrology Paper Irrigation in Africa, Europe and Latin America Update of the Digital Global Map of Irrigation Areas to Version 4 by Stefan Siebert Institute of Physical Geography University of Frankfurt (Main), Germany and Jippe Hoogeveen and Karen Frenken Land and Water Development Division FAO, Rome, Italy Frankfurt Hydrology Paper 5 Institute of Physical Geography University of Frankfurt (Main), Germany December 2006 Frankfurt Hydrology Papers: 01 A Digital Global Map of Irrigated Areas – An Update for Asia 02 Global-Scale Modeling of Nitrogen Balances at the Soil Surface 03 Global-Scale Estimation of Diffuse Groundwater Recharge 04 A Digital Global Map of Artificially Drained Agricultural Areas 05 Irrigation in Africa, Europe and Latin America - Update of the Digital Global Map of Irrigation Areas to Version 4 Institute of Physical Geography, Frankfurt University P.O. Box 11 19 32, D-60054 Frankfurt am Main, Germany Phone +49 (0)69 798 22393, Fax +49 (0)69 798 25058 http://www.geo.uni-frankfurt.de/ipg/ag/dl/index.html Please cite as: Siebert, S., Hoogeveen, J. & Frenken, K. (2006): Irrigation in Africa, Europe and Latin America - Update of the Digital Global Map of Irrigation Areas to Version 4. Frankfurt Hydrology Paper 05, Institute of Physical Geography, University of Frankfurt, Frankfurt am Main, Germany and Food and Agriculture Organization of the United Nations, Rome, Italy. The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders. Applications for such permission should be addressed to the Chief, Publishing and Multimedia Service, Information Division, FAO, Viale delle Terme di Caracalla, 00100 Rome, Italy or by e-mail to [email protected] © FAO 2006 Contents Preface VI Acknowledgements VIII Glossary IX Summary XII 1. Data and Methods 13 1.1 Mapping methodology 13 1.2 Assessment of map quality 13 1.3 The map of subnational unit boundaries used to update for the 14 Global Map of Irrigation Areas to version 4 1.4 Subnational irrigation statistics and geospatial information used to 15 update the Global Map of Irrigation Areas to version 4 2. Results and discussion 113 2.1 Area equipped for irrigation and map quality in map version 4 113 2.2 Differences between map version 3 and map version 4 113 2.3 Discussion of map quality 119 Appendix A Calculation of indicators of map quality and related marks for map 123 quality at the country, regional or global scale Appendix B Maps B1-B7 126 Preface Agriculture is by far the largest water-use sector, accounting for about 70 percent of all water withdrawn worldwide from rivers and aquifers for agricultural, domestic and industrial purposes. In several developing countries, irrigation represents up to 95 percent of all water withdrawn, and it plays a major role in food production and food security. The agriculture development strategies of most of these countries depend on the possibility of maintaining, improving and expanding irrigated agriculture. However, as the pressure on water resources increases, irrigation is facing growing competition from other water-use sectors and becoming a threat to the environment in an increasing number of regions. In the last decade, the international community has made major efforts to assess the different elements of the water balance and to predict current and future water needs for the different use sectors. However, considerable uncertainty remains concerning the extent and distribution of irrigated land in the world and on agricultural water use, therefore, making it difficult to monitor the irrigation sector adequately. Coverage of irrigated areas in the world, available in a geographical information system (GIS), is the single most important item of information needed to improve future global studies on water and food. The first version of the Digital Global Map of Irrigated Areas was published in 1999 (see table). It consisted of a raster map with a resolution of 0.5 ° by 0.5 ° containing the percentage of the area that was equipped for irrigation around 1995, the so-called irrigation density. To further develop and improve the global GIS coverage of areas equipped for irrigation and to make it available to users in the international community, cooperation was established between the Johann Wolfgang Goethe University in Frankfurt am Main, Germany, and the Land and Water Development Division of the Food and Agriculture Organization of the United Nations (FAO). Through this cooperation, the mapping project has been linked closely to the FAO global information system on water and agriculture, Aquastat. The Aquastat programme collects and disseminates data and information by country and by region. Its aim is to provide users interested in global, regional and national analysis (e.g. policy-makers, decision-makers and researchers) with the most accurate, reliable, consistent and up-to-date information available on water resources and agricultural water management. In order to make thorough analyses, the Aquastat programme collects data from many different sources including national water resources and irrigation master plans, statistics and yearbooks, FAO technical reports, and national and international surveys and reports made available by national and international research centres. The data collected through the Aquastat programme have served as the main source for improving the overall quality and resolution of the Digital Global Map of Irrigated Areas. In addition, the methodology for producing the map has been improved substantially. This has made it possible to increase the spatial resolution of the map to 5 minutes, thus justifying the publication of an improved second version of the Digital Global Map of Irrigated Areas. For Version 2, updated maps of Latin America, Europe, Africa and Oceania have been published. The next step in improving the dataset was the inclusion of updates for the continent of Asia, and for North America. With this update to version 3, the map for the whole globe was generated by using the same methodology. Here we present the update to version 4 which incorporates improvements for the continents of Africa and Europe and for parts of Latin America as well. For the update the inventory of subnational irrigation statistics for the continent was compiled. The reference year for the update of the map is 2000. VI Brief history of the Digital Global Map of Irrigation Areas 1999 Version 1 Digital Global Map of Irrigated Areas Version 1 published (resolution: 0.5 ° × 0.5 °). Döll, P. & Siebert, S. 1999. A digital global map of irrigated areas. Germany, Center for Environmental Systems Research, University of Kassel. 2001 Version 2 Cooperation was established between the project team of the Global Map of Irrigated Areas and the FAO Aquastat programme. As a result of this cooperation, the map-generation methodology was improved and an update of the continents of Latin America and Europe was made. The global grid resolution was increased to a grid of 5 arc- minutes and the map was made available to the general public as Version 2. Siebert, S. & Döll, P. 2001. A digital global map of irrigated areas - an update for Latin America and Europe. Germany, Center for Environmental Systems Research, University of Kassel. 2002 Version 2.1 Update of Africa and Oceania using the improved map-generation methodology described in Siebert & Döll (2001). Siebert, S., Döll, P. & Hoogeveen, J. 2002. A digital global map of irrigated areas - an update for Africa and Oceania. Germany, Center for Environmental Systems Research, University of Kassel, and Rome, FAO (available at http://www.fao.org/ag/agl/aglw/aquastat/irrigationmap/index.stm). 2004 The Global Map of Irrigated Areas project team at the University of Kassel moved to the Johann Wolfgang Goethe University in Frankfurt am Main, Germany. 2005 Version 2.2 Update of the continent of Asia using the map-generation methodology described in Siebert & Döll (2001). Siebert, S., Feick, S. & Hoogeveen, J. 2005. A digital global map of irrigated areas - an update for Asia. Frankfurt am Main, Germany, Johann Wolfgang Goethe University, and Rome, FAO. 2005 Version 3 Update of the map for North America, assessment of the map quality of map version 3 based on two indicators of map quality. Siebert, S., Döll, P., Hoogeveen, J., Faurès, J-M., Frenken, K. & Feick, S. 2005. Development and validation of the global map of irrigation areas. Hydrology and Earth System Sciences, 9, 535-547. 2006 Version 4 Update of the map for the continents of Africa and Europe and for parts of Latin America using the methodology described in Siebert et al. (2005). Siebert, S., Hoogeveen, J. & Frenken, K.