Assessing driving factors and future trends of ecological vulnerability in the upper reaches of the yangtze river

The upper reaches of the Yangtze River (URYR) constitute a crucial ecological barrier in China. However, its ecosystem faces dual threats from climate change and human activities. Research on the driving factors and future trends of ecological vulnerability (EV) in this region remains inadequate, which constrains the formulation of ecosystem conservation strategies. This study assessed the characteristics of EV in the URYR. The individual and interactive effects of various factors on EV were analyzed by constructing an interactive geographically and temporally weighted regression. Additionally, future EV trends under different scenarios were predicted using the CA-Markov model. The results indicate that EV index decreased from 0.359 in 2007 to 0.346 in 2023, exhibiting a spatial pattern of higher in the north and lower in the south. The individual and interactive effects of climate change and human activities on EV displayed spatial heterogeneity. Moreover, the impact of interactive effects on EV was more notable. Under the natural development scenario, EV is projected to stabilize in the early prediction period, and then show a notable declining trend in the later prediction period. This study provides scientific evidence for proactive ecosystem conservation in the URYR.