Dynamic processes of water conflicts and their coupling with water crises in Asia’s transboundary river basins

• The coupling relationship between water conflict and water crisis is quantitatively calculated. • "South Asia-West Asia" has the highest concentration of transboundary water conflicts. • Water conflict and water stress have obvious coupling relationships in Asian transboundary river basins. As water resources become more scarce, transboundary river basins in Asia are hotspots of global water conflicts and areas with high water security risks. However, the dynamics of water conflicts in Asian transboundary river basins and the coupling relationship between water conflicts and water crisis are poorly understood. Therefore, this study thoroughly examined the spatiotemporal changes in water conflict events (1948–2022) and quantitatively assessed the coupling degree and causality between water conflict and water crisis based on transboundary water event database, water stress index (WSI), correlation coefficient and the Granger causality tests. The conclusions showed an increase in the number of transboundary water conflicts in Asia, with “South Asia-West Asia” being the most intensive area, and the Jordan and Tigris-Euphrates/Shatt Al-Arab river basins in West Asia having the highest number of water conflicts, with 294 and 291 cases, respectively. Followed by the Indus river basin in South Asia (215). On a national scale, bilateral conflicts between Syria-Turkey and India-Pakistan were the most frequent. The water crisis was increasing in almost river basins, and the Indus and Jordan river basins are experiencing “severe water stress”. Water conflict and water stress have obvious coupling relationships in Asian transboundary river basins, and the three basins with the strongest water conflicts (Jordan, Tigris-Euphrates/Shatt Al-Arab, and Indus river basins) all showed significant positive correlation and unidirectional causal relationship with the water stress.