Transboundary waters account for 60% of the Earth’s freshwater flows.
A watershed is an area of land that drains water into a body of water, such as a river, lake, or ocean; therefore, they are geographic regions defined by the natural boundaries of water flow. There are 276 transboundary watersheds in the world:
- 68 in Europe
- 64 in Africa
- 60 in Asia
- 46 in North America
- 38 in South America
International River Basins
In addition:
- 153 countries (and areas) share transboundary waters
- 200 transboundary aquifers are recorded
- There are 592 transboundary aquifer systems
- 40% of the world’s population lives in these basins
In addition:
- The 263 transboundary lakes and river basins constitute almost half of the Earth’s surface.
- 21 countries are located entirely within international basins.
- 39 countries share more than 90% of their territory with one or more other countries through transboundary rivers.
Transboundary Hydrological basins
- While most of the basins are shared by two countries, in many others the number is much higher. There are 13 basins worldwide shared between 5 and 8 nations.
- Five other basins, involving the Congo, Niger, Nile, Rhine and Zambezi rivers, are shared between 9 and 11 countries.
- The river that crosses the largest number of countries is the Danube, which flows through the territory of 18 nations.
- 58% of the world’s transboundary basins are subject to operational arrangements for water cooperation (indicator 6.5.2 of the Sustainable Development Goals, SDGs, 2020).
- More than 3 600 agreements and treaties related to transboundary waters have been signed.
References
PNUD, Programa de las Naciones Unidas para el Desarrollo. (2006). Capítulo 6. En: Informe sobre Desarrollo Humano 2006. Más allá de la escasez: poder, pobreza y crisis mundial del agua. Recuperado de https://www.un.org/spanish/waterforlifedecade/transboundary_waters.shtml
Red del Agua UNAM. (25 nov 2019). Aguas transfronterizas. Recuperado de https://youtu.be/DIE-7qySLE0?si=LXwg91Hcp_Ws83oQ
UN Water. (s.f.). Transboundary waters. Recuperado de https://www.unwater.org/water-facts/transboundary-waters y https://sdg6data.org/en/country-or-area/Mexico#anchor_6.5.2
