Capturing land use system thresholds through regime shifts of coastal sustainability in China

Land use change (LUC) plays a critical role in influencing progress toward the Sustainable Development Goals (SDGs), especially in rapidly urbanizing coastal regions. While global SDG implementation has made notable strides, the non-linear and threshold-based effects of LUC on regime shift of SDG systems remain underexplored. This study examines how LUC has affected SDG performance in eastern coastal China between 2015 and 2020, with a focus on identifying critical tipping points. Results confirm a marked shift in sustainability focus—from inequitable economic growth toward enhanced social and climate resilience. The overall SDG index increases by 18 %, with SDG5 (Gender Equality), SDG13 (Climate Action), and SDG16 (Peace and Justice) showing gains of over 20 %. In contrast, SDGs 9, 14, and 17 remain stagnant. Key thresholds are identified: impervious surfaces exceeding approximately 10 %, cropland reaching 26.7–41.7 %, and forest cover beyond 56.5 % were associated with diminishing or adverse effects on SDG performance. These findings highlight the necessity of recognizing land use system thresholds to mitigate risks of sustainability decline. This study provides evidence-based guidance for land use planning that balances development with environmental and social objectives.