Environmental sustainability in the Lancang–Mekong River Basin: Research progress, emerging themes, and future directions under climate change and hydropower development

Climate change and hydropower development are reshaping environmental sustainability in the Lancang–Mekong River Basin (LMRB) through their interacting effects on hydrological processes, ecosystems, water resources, and socioeconomic systems. This study provides an integrated review of environmental sustainability research in the LMRB by combining scientometric analysis with systematic thematic synthesis. A total of 356 publications indexed in the Web of Science Core Collection from 2005 to 2024 were analyzed to characterize the evolution of research output, collaboration patterns, influential studies, and major thematic hotspots. The reviewed literature is concentrated around three broad themes: climate change and hydrological change, environmental degradation and ecosystem responses, and hydropower development and water-resource interactions. The synthesis further highlights important concerns related to river connectivity, sediment and fisheries, biodiversity, water quality, and the social consequences of environmental change. An indicator-based comparative risk characterization shows that connectivity loss and sediment–fishery interactions represent particularly important environmental pressures, while social dimensions such as equity, vulnerability, public health, and adaptive capacity remain comparatively underrepresented in basin-scale assessments. Future research should strengthen multi-source data integration, cumulative-impact assessment, environmental–socioeconomic analysis, and transboundary cooperation to support more adaptive and integrated sustainability management across the basin.