About & method
Transboundary Waters Atlas is an independent, data-driven atlas of the world's shared rivers and aquifers. Everything on this site is built from published, citable datasets — and where the data runs out, we say so on the page rather than papering over it.
Scope
This atlas covers exactly two things: international river basins (310, per the TFDD — Transboundary Freshwater Dispute Database — register) and transboundary aquifers (426, per the IGRAC — International Groundwater Resources Assessment Centre — /UNESCO 2025 map) — the water that crosses borders on the surface, and the water that crosses them underground.
Where are the lakes? Inside their basins. The Aral Sea, Lake Chad and the African Great Lakes are already basins in the TFDD register or sit inside larger ones (the Great Lakes within the Nile and Congo systems), so they appear as basin stories rather than a third category.
Where are the wetlands? Inside the stories — the Danube Delta, the Sudd, the Tonlé Sap. There is no comparable global register of transboundary wetlands, and this atlas does not invent categories its sources cannot support.
The cooperation indicator
Every story carries a cooperation status from 1 (high tension) to 5 (strong cooperation). It is a composite of three published measures, always shown with its sub-dials and a caveat — never as a bare colour. Conflict and cooperation coexist on most shared waters; a high score means institutions absorb the conflict, not that conflict is absent.
What has actually happened between the countries: 7,128 water-related interactions scored on the BAR intensity scale in the TFDD International Water Events Database (Basins at Risk; Yoffe, Wolf & Giordano). Each story shows its real event count, mean intensity and cooperative share — but this record ends in 2008, so recent tension (the GERD, 2011; the Lake Chad insurgency, 2014) is invisible here and carried instead by the conflict dial.
What has been agreed: treaty count, scope, groundwater provisions and river basin organizations, computed directly from the TFDD International Freshwater Treaties Database (882 treaties, 1820–2023). It also colours the world map and drives the treaty explorer.
What works today: the share of each basin covered by operational cooperation arrangements under UN SDG indicator 6.5.2 (third reporting round, 2023/24), basin-area-weighted across the riparians that reported. Where a country did not report — Egypt and Ethiopia on the Nile — we say so rather than infer; the gap is itself informative.
Not part of the cooperation score: the Pacific Institute Water Conflict Chronology (2,758 events through 2025) records water-conflict events across each basin's countries — national and local, not only transboundary. It is the recent-tension counterweight to a treaty record that skews cooperative and a state-event record that stops in 2008.
Honesty box: all three legs are now computed from public data (events, treaties, SDG 6.5.2), and every story sub-dial shows its real number and vintage. What stays editorial is the overall 1–5 badge — a synthesis that also weighs the recent Pacific Institute record, because the state-event data ends in 2008 and the treaty record skews cooperative. A high badge means institutions absorb conflict, not that conflict is absent; a low one means the institutions are thinner than the stakes. For most of the 426 aquifers no assessment exists at all — that emptiness is a finding, shown as grey rather than guessed.
Data lineage
| On the site | Source | Status in this build |
|---|---|---|
| 310 river basins | TFDD Register of International River Basins, Oregon State University, 2019 revision. Map geometry: TFDD basin–country polygons (276 basins mapped). | Real data |
| 426 aquifers | IGRAC/UNESCO Transboundary Aquifers of the World, 2025 — full geometry, lithology, boundary-data reliability and SDG 6.5.2 comparison from the Global Groundwater Information System. | Real data |
| 882 treaties & timelines | TFDD International Freshwater Treaties Database (Feb 2023 edition): 3,812 basin–country rows, deduplicated by treaty ID; groundwater scores per treaty. | Real data |
| "40% of humanity" | UN-Water / SDG 6.5.2 metadata: ~40% of the world's population lives in transboundary river and lake basins; over 90% lives in a country sharing one. No equivalent figure exists for aquifers — a data gap we keep visible rather than merge away. | Sourced stat |
| Cooperation sub-dials | Three computed legs: TFDD event balance (Water Events Database, 7,128 events 1948–2008, BAR scale), treaty depth, and SDG 6.5.2 (2023/24). The overall 1–5 badge is an editorial synthesis of these plus the recent conflict record. | Computed + framed |
| Conflict timeline & strips | Pacific Institute Water Conflict Chronology (2,758 events, updated Nov 2025) — global by decade, and per basin across its countries. Categorised trigger / weapon / casualty. | Real data |
| Country lens: SDG, dependency, conventions | SDG 6.5.2 country values (UNSD series EG_TBA_H2CO); water-dependency ratio (FAO AQUASTAT); parties to the UN Watercourses (1997) and UNECE Water (1992) Conventions, as of 2024. | Real + curated |
| Institutions directory | International RBO Database (Schmeier, 2013): 117 river basin organizations with institutional-design attributes. Story institution cards updated to current membership. | Real (2013) |
| Expert & local voices | Named experts are real researchers in the correct fields; quotes are clearly-flagged paraphrases of their published work pending direct confirmation. Local voices are composites from published interviews, never presented as named individuals. | Flagged on page |
| Photography | Wikimedia Commons and public agency imagery (NASA, ESA/Copernicus), each credited with photographer and license under its caption. | Licensed & credited |
| Film | Licensed stock footage from the project's own library, transcoded for web with poster-frame fallbacks for reduced-motion and slow connections. | Licensed |
Citation for TFDD materials: "Product of the Transboundary Freshwater Dispute Database, College of Earth, Ocean, and Atmospheric Sciences, Oregon State University." · Aquifer data © IGRAC & UNESCO 2025.