Global Study Reveals Critical Sustainability Gaps in Transboundary River Basins

A new global assessment of transboundary river basins reveals these shared water systems face significantly greater sustainability challenges than nationally contained water resources, with an average Sustainable Development Goals Index score of just 42 out of 100 compared to the global national average of 67. The study, published in Environmental Science and Ecotechnology, analyzed 310 basins worldwide using a novel framework that combines environmental inequality metrics with 98 SDG indicators.

The research team from Nanjing University, the Chinese Academy of Sciences, and Stockholm University developed a four-step framework that first mapped high-resolution water availability and socio-environmental data, then calculated Environmental Gini coefficients to quantify inequalities between upstream and downstream regions. These metrics were combined with SDG Index data to produce composite scores for each basin, revealing striking regional contrasts from African basins scoring as low as 13 to European rivers surpassing 75.

The analysis identified four distinct basin profiles based on their challenges and characteristics. Institutional governance basins, such as the Amur and Yukon, have relatively strong governance but require deeper cooperation. Sustained growth basins like the Niger face poor water quality, poverty, and disease burdens. Inclusive growth basins including the Seine and Rhine–Meuse balance economic strength with environmental pressures, while social coordination basins such as the Amazon and Mekong are highly exposed to floods and droughts.

Scenario modeling demonstrated that achieving clean water (SDG 6) alone would only bring 17 basins to sustainability. Combining clean water with economic growth (SDG 8) increases that share to 17%, while achieving SDGs 3 (health), 6, and 8 together could elevate 38% of basins into sustainability. The findings underscore that multi-goal, basin-specific strategies offer far greater potential than isolated interventions.

Lead author Yiqi Zhou emphasized that the research exposes a hidden layer of inequality in shared water systems that national statistics fail to capture. The framework provides policymakers with a decision-making compass that can guide targeted investments in infrastructure, governance reforms, and cross-border agreements. By aligning efforts across clean water, livelihoods, and health, such integrated strategies could help ease geopolitical tensions, fortify resilience against climate shocks, and accelerate progress toward multiple Sustainable Development Goals.

The study's implications extend beyond environmental management to international relations and global security, as transboundary basins provide food, energy, and biodiversity while demanding complex governance that often falters under competing national priorities. Climate change, rising populations, and land-use shifts intensify upstream-downstream tensions, making this comprehensive assessment particularly timely for guiding effective interventions in some of the world's most sensitive shared river systems.