Transboundary Aquifers of the World - 2025 Edition

The map Transboundary Aquifers of the World provides an overview of aquifers that cross international borders. Developed over more than 15 years, the map synthesizes findings from regional and aquifer-specific studies to reflect the most up-to-date knowledge. Each new edition incorporates scientific advances and improved data access.

This edition (2025) is based on a review of approximately 130 references, including peer-reviewed scientific publications as well as grey literature. Additional data were obtained from regional centres, institutions and individual experts. All references are cited in the online attribute table.

For the first time, this edition includes basic descriptive information for each TBA, where available, such as the type of aquifer and main lithology. This information is also accessible in the attribute table.