Transboundary hydrological basins span international borders and are essential to global water systems, human development, and environmental sustainability. Nearly 40 % of the world's population lives within these basins, which supply critical resources such as freshwater, food, energy, and biodiversity. Yet their sustainability remains poorly understood, as existing assessments often overlook the unique social, environmental, and political complexities of transboundary basins. This study addresses that gap by developing and applying a systematic framework to assess Sustainable Development Goals (SDGs) progress across 310 transboundary basins worldwide. Here we show that transboundary basins score significantly lower on average SDGs achievement (an SDG Index score of 42 on a scale of 0–100) compared to national averages (a score of 67), with considerable variation between regions. We identify four distinct types of transboundary basins in terms of SDGs achievement and associated challenges. We also show that progress on a specific set of goals can drive broader sustainability within each basin type. Notably, achieving clean water (SDG 6), sustainable economic growth (SDG 8), and healthy livelihoods (SDG 3) is linked to overall SDGs success in 38 % of transboundary basins worldwide. Our results highlight the importance of basin-level analysis for revealing sustainability patterns overlooked by national assessments. This framework can inform future basin research and support policy development in transboundary regions.

Public welfare land allocation in China’s land expropriation process plays a crucial role in balancing economic development with social equity, but limited research has examined the driving factors influencing public welfare land ratio determination from a central–local relationship perspective. This study investigates how central–local government interactions shape public welfare land ratios in China’s land development process. Based on a comprehensive analysis of land expropriation data across different regions and administrative levels, we examine the spatial heterogeneity and underlying mechanisms of public welfare land allocation. The results reveal the following: (1) Significant regional variations exist for regional public welfare land ratios, with the national average public welfare land ratio reaching 41.21% in 2019 (for plots ≥4 hectares), varying from 39.60% in eastern regions to 44.93% in western regions. (2) Administrative hierarchy influences allocation patterns, with county-level cities (43.73%) showing higher proportions than provincial capitals (36.42%). (3) Local governments strategically use public welfare land development as an instrument to expand land-based fiscal resources by attracting investments and population. (4) Provincial governments serve as crucial intermediaries in central–local policy implementation, balancing central mandates with local conditions. This study contributes to the land governance literature by providing empirical evidence on how institutional arrangements affect land resource allocation. The findings suggest that establishing unified national standards while allowing provincial-level adaptations would improve the effectiveness of public welfare land policy in the post-land finance era, enhancing both governance efficiency and public welfare outcomes.