Proportion of land salinized due to irrigation (Global)

This map, compiled to support the analysis of SOLAW report concerning trends and current use of water use in agriculture, shows the percentage of irrigated area supplied by groundwater. Irrigation mainly relies on renewable freshwater resources, either surface water or groundwater. However, while the extent of irrigation and related water uses are reported in statistical databases or by model simulations, information on the source of irrigation water is still very rare. A recent global inventory undertaken by FAO and the University of Bonn reports that 113 million ha, or 38 percent of the total area equipped for irrigation of 301 million ha, is irrigated by groundwater (Siebert et al, 2010). **Data creation:** 2025-12-11 **Contact points:** Metadata Contact: [AQUASTAT](mailto:aquastat@fao.org) **Data lineage:** Input data for this map include: - Global map of irrigation areas at 5 arc-min (Siebert et al., 2007) - Data on sources of irrigation water available by country through the FAO AQUASTAT database - Additional data obtained through desk studies on distribution of sources of irrigation water. The legend indicates the share of irrigated land serviced by groundwater in each pixel. **Resource constraints:** This work is made available under the Creative Commons Attribution 4.0 International license (CC-BY-4.0) **Online resources:** Download - Percentage of irrigated area serviced by groundwater (ESRI GRID) SOLAW web page

This map shows the extent of land area equipped for irrigation -expressed as percentage- around the turn of the 20th century according to the Global Map of Irrigation Areas (version 4.0.1), together with areas of rainfed agriculture. Data are available from AQUASTAT - programme of the Land and Water Division of the Food and Agriculture Organization of the United Nations. **Data publication:** 2010-10-28 **Contact points:** Metadata Contact: [AQUASTAT](mailto:aquastat@fao.org) **Data lineage:** The spatial datasets used to produce this map are: - The global map of irrigation areas at 5 arc-min (Siebert et al., 2007) - The cropland categories of the global agricultural systems map (SOLAW report "Managing Systems at Risk", map 1.3). **Resource constraints:** copyright **Online resources:** SOLAW website Download- Percentage of area equipped for irrigation (ESRI GRID) GMIA page on AQUASTAT

Global Map of Irrigation Areas - Version 5 Grid with percentage of area equipped for irrigation with a spatial resolution of 5 arc minutes or 0.083333 decimal degrees. This dataset is developed in the framework of the AQUASTAT Programme of the Land and Water Division of the Food and Agriculture Organization of the United Nations and the Rheinische Friedrich-Wilhems University, Germany. The map shows the amount of area equipped for irrigation around the year 2005 in percentage of the total area on a raster with a resolution of 5 minutes. Additional map layers show the percentage of the area equipped for irrigation that was actually used for irrigation and the percentages of the area equipped for irrigation that was irrigated with groundwater, surface water or non-conventional sources of water. In details, the following products have been released and made available for download: - Area equipped for irrigation expressed as percentage of total area: total=aei, surface water=aeisw, groundwater=aeigw, non-conventional sources of water=aeinc (ASCII-grid); - Area actually irrigated expressed as percentage of area equipped for irrigation (ASCII-grid); - Area equipped for irrigation expressed in hectares per cell (ASCII-grid); - Irrigated areas v.5 (ESRI shapefile); - High and low resolution images (PDF); - Quality Assessment (Excel) Due to the map generation method, the quality of the map can never be uniform. The overall quality of the map depends heavily on the individual quality of the data for the different countries. **Data revision:** 2013-10-07 **Supplemental Information:** The maps are generated as a grid with a cellsize of 5 arc minutes. For the GIS-users the maps are distributed in two different formats: as a zipped ASCII-grid that can be easily imported in most GIS-software that support rasters or grids; and, to accommodate people who use GIS-software that doesn't support rasters or grids, as a zipped ESRI shape file. The non-GIS-users can download the map as PDF-file in two different resolutions. **Citation:** Users are requested to refer to the map as follows: "Stefan Siebert, Verena Henrich, Karen Frenken and Jacob Burke (2013). Global Map of Irrigation Areas version 5. Rheinische Friedrich-Wilhelms-University, Bonn, Germany / Food and Agriculture Organization of the United Nations, Rome, Italy". **Contact points:** Metadata Contact: [AQUASTAT](mailto:aquastat@fao.org) **Data lineage:** Due to the map generation method, the quality of the map can never be uniform. The overall quality of the map depends heavily on the individual quality of the data for the different countries. **Resource constraints:** This work is made available under the Creative Commons Attribution 4.0 International license (CC-BY-4.0) **Online resources:** Global Map of Irrigation Areas (GMIA) on the AQUASTAT website Download - Global area equipped for irrigation expressed as percentage of total area - Raster (ASCII-grid, 2.3 MB) Download - Global area equipped for irrigation expressed in hectares per cell - Raster (ASCII-grid, 2.3 MB) Download - Global Map of Irrigation Areas v.5 - Vector (ESRI shapefile, 4 MB) Download - Global Map of Irrigation Areas v.5 - All files Download - Global Map of Irrigation Areas v.5 - High resolution image (PDF, 3.1 MB) Download - Global Map of Irrigation Areas v.5 - Low resolution image (PDF, 0.9 MB)

This map builds upon work done by Dixon (Dixon et al., 2001) in an attempt to propose a general classification of major farming systems. Based on a combination of global dataset, the map proposes a harmonized classification of major agricultural systems used as the basis for the analysis of SOLAW's Systems at risk. The map is based on an interpretation of global land cover data, combined with thematic datasets showing irrigated land and paddy rice extent. The map is published in SOLAW Report: The state of the world's land and water resources for food and agriculture - Managing systems at risk (2011) and SOLAW Thematic Report 15: Sustainable options for addressing land and water problems - a problem tree and case studies (links in the online resources section). **Data publication:** 2010-11-02 **Contact points:** Metadata Contact: [AQUASTAT](mailto:aquastat@fao.org) Resource Contact: [Jippe Hoogeveen](mailto:Jippe.Hoogeveen@fao.org) Resource Contact: Hubert George FAO-UN Land and Water Division **Data lineage:** The spatial datasets used for the production of this map consist of: - GLOBCOVER, global land-cover map for the year 2005 at http://www.gofc-gold.uni-jena.de/sites/globcover.php - Paddy rice systems (Ellis and Ramankutty, 2008) - Median altitude and thermal climates (both datasets are part of the GAEZ v3.0 (IIASA/FAO, 2010) - Global Map of Irrigation Areas v4.0.1 at 5 arc-min (Siebert at al., 2007) - Global Map of Aridity at 10 arc-min (FAO) - Global Administrative Unit Layers (GAUL 2008) - FAO’s Global Livestock Production and Health Atlas (GLiPHA, available at: http://www.fao.org/ag/againfo/home/en/news_archive/AGA_in_action/glipha.html) - FAO’s Agro-MAPS, available at (http://kids.fao.org/agromaps/) **Resource constraints:** This work is made available under the Creative Commons Attribution 4.0 International licence (CC-BY-4.0) **Online resources:** SOLAW website Download - Agricultural systems (ESRI GRID) Download - Agricultural systems - (ASCII grid with Vat table and class codes) Download - Agricultural systems (GeoTiff) The state of the world's land and water resources for food and agriculture - Managing systems at risk. Sustainable options for addressing land and water problems - a problem tree and case studies.

This dataset includes global soil salinity layers for the years 1986, 1992, 2000, 2002, 2005, 2009 and 2016. The maps were generated with a random forest classifier that was trained using seven soil properties maps, thermal infrared imagery and the ECe point data from the WoSIS database. The validation accuracy of the resulting maps was in the range of 67–70%. The total area of salt affected lands by our assessment is around 1 billion hectares, with a clear increasing trend. Further details are provided in a peer-reviewed journal article (https://doi.org/10.1016/j.rse.2019.111260). The code and data used to produce the global soil salinity maps can be accessed by registered Google Earth Engine users at https://code.earthengine.google.com/d43e5a92ae1deed32a0929f57b572756.

Agricultural irrigated land refers to agricultural areas purposely provided with water, including land irrigated by controlled flooding.