Global Map of Irrigation Areas
Obtain the latest version
The latest version of the "Global Map of Irrigation Areas" is version 4.0.1 which can be downloaded from this page. The documentation of the map includes an explanation of the methodology, information per country, an assessment of the map quality, and references to the background and history of the irrigation mapping project.
The map shows the amount of area equipped for irrigation around the turn of the 20th century in percentage of the total area on a raster with a resolution of 5 minutes. The area actually irrigated was smaller, but is unknown for most countries. A special note has to be made for Australia and India where the map shows the total area actually irrigated. This is due to the fact that statistics collected in Australia and India refer to actually irrigated area as opposed to statistics with area equipped for irrigation which are collected in most other countries. An explanation of the different terminology to indicate areas under irrigation is given in this glossary.
Users are requested to refer to the map as follows: "Stefan Siebert, Petra Döll, Sebastian Feick, Jippe Hoogeveen and Karen Frenken (2007) Global Map of Irrigation Areas version 4.0.1. Johann Wolfgang Goethe University, Frankfurt am Main, Germany / Food and Agriculture Organization of the United Nations, Rome, Italy".
The map is generated as a grid and distributed with the following charactersitics:
| Projection: | Geographic |
| Number of columns: | 4320 |
| Number of rows: | 2160 |
| North Bounding Coordinate: | 90 degrees |
| East Bounding Coordinate: | 180 degrees |
| South Bounding Coordinate: | -90 degrees |
| West Bounding Coordinate: | -180 degrees |
| Cellsize: | 5 minutes, 0.083333 decimal degrees |
| NODATA values: | Cells without irrigation are characterised by NODATA (-9), it does not mean that there was no data for these cells |
A preview of the map can be seen here. For the GIS-users the map is distributed in two different formats: as zipped ASCII-grid that can be easily imported in most GIS-software that support rasters or grids; and, to accomodate people who use GIS-software that doesn't support rasters or grids, as a zipped ESRI shape file. It should be noted, however, that the values in the ASCII-grid have a precision of 6 decimals while the values in the shape-file have a precision of 2 decimals. For model calculations it is therefore recommended to use the grid-version. As a service to those people who would need to know the absolute area equiped for irrigation, another ASCII-grid is available in which the area equipped for irrigation is expressed in hectares per cell. Non-GIS-users can download the map as PDF-file in two different resolutions.
Users of Google Earth can see the Global Map of Irrigation Areas as an overlay by opening this file in Google Earth.
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