Water has been a main issue on the international agenda for the last 30 years, starting with the 1st International Conference on Water (Mar de la Plata, 1977), and followed by the International Conference on Water and the Environment (Dublin, 1992) and the 1st World Water Forum (Marrakech, 1997). During the 2nd World Water Forum in The Hague in March 2000, the United Nations pledged to produce a periodic assessment of the state of the world’s freshwater resources in the form of the World Water Development Report (WWDR), with which FAO is associated closely. In view of the critical role of water in food production and of the importance of agriculture in global water withdrawal, and in order to provide a basis for the discussion on increasing water scarcity and the future of irrigation in the world, FAO undertook to compile existing information on water resources in the framework of the Aquastat programme.
Developed since 1993 by FAO’s Land and Water Development Division, the Aquastat programme is FAO’s global information system on water and agriculture with a focus on irrigation. Its main purpose is to select systematically the most reliable information on water resources and water uses in countries and to make it available in a standard format to users interested in global or regional perspectives. Its objectives are:
To provide users with comprehensive information on the state of agricultural water management across the world, with an emphasis on developing countries and countries in transition, and featuring major characteristics, trends, constraints and prospective changes.
To support continental and regional analyses by providing systematic, up-to-date and reliable information on water in agriculture and to serve as a tool for large-scale planning and predictive studies.
All the results produced by the Aquastat programme are available as published reports or on CD-ROM and are available on the World Wide Web (regional overviews, country profiles, a glossary, and an atlas of water resources and irrigation in Africa). For specific information by country, the user can query two online databases on: (i) water and agricultural data; and (ii) regional and national institutions dealing with water and agriculture.
Little information exists on water resources on a regional basis at country level. The only study that produced country figures systematically was conducted in the 1970s. It led to a publication entitled “World water resources and their future” (L’vovitch, 1974), which remains in use as a reference work in this field. Based on a water balance approach and drawing on a large amount of information on stream flow gathered from around the world, it proposed a table of water resources by country, including water resources generated in the country and flows from neighbouring countries. Also based on a water balance approach and following the work of Korzun et al. (1974), the publications by Shiklomanov (1997, 1998 and 2000) are the most frequently cited and up-to-date sources of information on water resources at regional and continental level. Shiklomanov (1998) provides country data for 51 countries on available water resources. Other useful compilations are by Gleick (2000) and the World Resources Institute (1994 and 2000). The latter provides the most recent systematic information about water resources at country level. It is mainly a compilation of existing information, including figures from Aquastat. These global data sources often do not indicate the method used to compile and validate their data sets.
In the framework of the Aquastat programme, a major focus has been the development of a consistent basis of assessment of water resources data in order to facilitate comparison between regions and countries. It is an important tool for enhancing regional and global discussion on water resources. The availability of country-level data on water resources is useful for:
providing a homogenous database for the calculation of national indicators of water resources: resources per inhabitant (current or long term); ratio of demand/resources; and dependency ratio. This is useful for comparing and classifying countries, especially where the situations in the countries are very diverse;
ensuring consistency in the estimation of the natural water exchanges between countries (transboundary and border flows);
assessing the level of knowledge on water resources for each country, and highlighting the needs for improvements in knowledge.
This survey gives priority to information available from the countries. It makes no use of global water balance models. Although such a method does not ensure homogeneity in the quality of information collected, it makes the best possible use of local knowledge.
It has devoted particular attention to reducing the risks of double counting for: (i) internal water resources when assessing surface water and groundwater separately; and (ii) external resources when accounting for transboundary waters or border rivers. The overall purpose is to obtain the most reliable and complete set of water resources data by country.
This report provides statistics on water resources for all the countries of the world. It presents a compilation and a critical review of available information. The aim is to help in harmonizing currently available global water resources databases. It covers information sources from the Aquastat country surveys undertaken since 1994, and the most recent available references from national or international sources for North America, Europe and the Pacific region. On the basis of a comparative analysis of water resources data by country according to different sources, FAO has compiled its best estimates of the main elements of the water balance for each country.
Chapter 2 presents the concepts and definitions used by Aquastat. Chapter 3 illustrates the methodology use to compute water resources by country, while Chapters 4 and 5 present and comment on the results at the world level and in an overview of its breakdown into ten regions. An annex (Annex 2) presents a summary table of the main water resources variables. All results are available on the Aquastat Web site.
