Spatiotemporal evolution and driving factors of ecological risks in the Wujiang River Basin over the past four decades

Elucidating the spatiotemporal changes in ecological risk is theoretically and practically significant for advancing regional ecological civilisation development and achieving watershed ecological security. A landscape ecological risk (LER) assessment model based on land use data spanning eight periods from 1990 to 2023 was established for the Wujiang River Basin. Through this model, the spatiotemporal differentiation and evolutionary characteristics of the intrabasin LER were systematically analysed. By integrating spatial autocorrelation analysis with the optimal parameterised geographic detector method, the dominant drivers of global and local spatial differentiation in ecological risk were identified. Between 1990 and 2023, the Wujiang River Basin LER was significantly positively spatially correlated with the drivers, demonstrating overall risk reduction. The high/medium–high-risk area proportion decreased from 11.48 to 4.02%. The low-risk area proportion increased from 5.75 to 52.68%. Temporal analysis revealed three distinct phases of ecological risk evolution: disturbance (1990–2000), reduction (2000–2015), and stabilisation (2015–2023). Landscape pattern changes influenced risk across phases. Socioeconomic factors dominated the spatial pattern of ecological risk. The combined effect of multiple drivers was greater than the effects of individual factors. This study provides systematic references and decision-making support for establishing ecological barriers, managing ecological risks, and optimising ecological spatial patterns in the upper Yangtze River territorial space.