[Land Use Change and Landscape Ecological Risk Assessment in the Heihe River Basin]

As a key ecological barrier in the arid region of Northwest China， the stability of the landscape ecosystem in the Heihe River Basin holds significant importance for the sustainable development of the basin. Based on four periods of remote sensing data from 1990 to 2023， this study takes land use change as the entry point and constructs a landscape ecological risk assessment system for the Heihe River Basin by coupling the landscape disturbance-vulnerability-loss model. It reveals the evolution characteristics of landscape ecological risk in the basin driven by land use changes over 33 years. The results indicate： ①From 1990 to 2023， land use changes in the Heihe River Basin exhibited a "reclamation-disequilibrium-restoration" pattern， with the core trend shifting from development to protection. ②The landscape ecological risk in the Heihe River Basin formed a latitudinal gradient differentiation of "high in the north and low in the south" and a longitudinal hierarchical spatial differentiation pattern of "downstream > midstream > upstream." ③The average landscape ecological risk in the Heihe River Basin increased from 0.063 3 to 0.068 7 before declining to 0.064 6， presenting an inverted U-shaped trajectory of "first rising then falling." Landscape ecological risk and land use changes showed significant spatial consistency， with ecological conditions gradually recovering. Therefore， land use changes in the Heihe River Basin are a key factor driving the evolution of ecological risks. By guiding land use changes through ecological risk zoning regulation to reduce landscape ecological risk， positive implications for the sustainable development of the basin can be achieved.