World map of rivers and groundwater basins

World map of rivers and groundwater basins

This card is one of the products of the international  World-wide Hydrogeological Mapping and Assessment Programme (WHYMAP). WHYMAP is a programme of UNESCO, the CGMW, the IAH (International Association of Hydrogeologists), the IAEA (International Atomic Energy Agency) and the BGR (German Federal Institute for Geosciences and Natural Resources).

This programme collects, compiles and evaluates hydrogeological data on groundwater on a continental and global scale in order to contribute to international discussions on water issues by making groundwater more visible. In order to do this, a synthesis of regional and national cartographic data is being carried out, and a geographic information system (WHYMAP-GIS) is being gradually built to manage and display the data.

The main objectives of this work are:

• Gathering information on groundwater resources worldwide.
• Share this data through maps and applications:
  • World map of groundwater resources at a scale of 1:25,000,000
  • Thematic maps at a scale of 1:50,000,000
  • Small-scale maps for use in water-related publications and presentations
  • WHYMAP application for open access on the web

• To provide decision-makers with informative maps for international discussions on water.
  • World Water Assessment Programme (WWAP)
  • World Water Development Reports (WWDR)
  • World Water Forum

• Exchanging groundwater data with other research and development programmes.

This map superimposes the major river and lake basins and the different hydrogeological categories of the underlying aquifers. This involves giving a two-dimensional representation to a three-dimensional reality, which is far from simple.

Rasters have been used to show the surface forms of river basins and lakes, and colour gradients to indicate the categories of aquifers, as the constraints associated with representation at a global level only allow the inclusion of large systems, alongside other smaller systems of local importance. Special screens have also been used to indicate possible relationships between groundwater and surface hydrogeological systems.

The printed version of this map is distributed by UNESCO, the CCMG and the BGR. Other products are available for free download at http://www.whymap.org

This 1:500,000 scale edition was specially prepared and published for the 6th World Water Forum held in Marseille in March 2012.

World map of rivers and groundwater basins