Escaping the development trap on sandbar islands: a case study on the Yangtze River

Global climate change intensifies hydrological extremes, challenging inhabited floodplain landscapes where environmental regulation, socio-economic decline, and institutional ambiguity co-produce persistent development traps. Research on sandbar islands – dynamic, inhabited landforms in large river systems – has largely overlooked the integration of social and economic dimensions. Using Tianxingzhou, a mid-Yangtze sandbar, as a critical case, this study integrates socio-economic conditions, natural resource and environmental characteristics, infrastructure status, governmental planning and regulatory guidance, and field observations with iterative SWOT analysis. Findings reveal a self-reinforcing development trap driven by four interacting dimensions: deteriorating socio-economic conditions (aging, outmigration, economic monostructure); vulnerable natural assets (fertile but flood-exposed); stagnant infrastructure (minimal public services); and policy stasis (no detailed spatial planning document update since 2013). These dimensions lock the island into a state where neither abandonment nor revitalization can proceed smoothly. A three-pillar sustainability framework (environmental–social–economic) is proposed, translating SWOT-derived strategies into testable heuristics. The framework provides a realistic pathway from lock-in to adaptive coexistence, with transferable principles for climate-vulnerable riverine and deltaic settlements worldwide. The findings offer a paradigm for balancing environmental conservation, socio-cultural engagement, and economic sustainability in ecologically sensitive island environments.