Influencing socio-economic development and ecological environment, water resources system vulnerability (WRSV) is becoming increasingly prevalent in high mountain areas, which are strongly affected by climate change. In this study, the Upper Yangtze River (UYZ) located in hinterland of the Tibetan Plateau was selected for assessing spatiotemporal variations in WRSV, predicting future WRSV and identifying the main influencing factors of WRSV. The spatiotemporal variations in WRSV were estimated based on a framework including sensitivity, exposure, hazard and adaptability, which considered impact of both natural and human activities on WRSV. Moreover, the main influencing factors of WRSV and its future evolution were obtained based on SPHY (Spatial Processes in Hydrology) model, GCMs (General Circulation Models) and attribution analysis. The average WRSV of the UYZ corresponded to medium-low grades during 2001–2019. Overall, the value and increasing trend of WRSV in downstream areas were higher than that of upstream areas. Under various scenarios (SSP 1–2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) with global warming of 1.5 °C and 2 °C, the average WRSV would continue to be of medium-low grade. However, the average WRSV of the basin and the area ratio for medium vulnerability and medium-high vulnerability would increase. As the main influencing factor, the hazard level contributed to more than 93% of the change in WRSV during both the historical and future periods. The results indicated that climate change may increase the WRSV of the UYZ and suitable countermeasures would be required to better cope with the impact of climate change on the water resources system. These findings provide a scientific basis for designing adaptive strategies to mitigate the adverse effects of climate change and achieve social and economic sustainable development.

影响社会经济发展和生态环境的水资源系统脆弱性（WRSV）在受气候变化影响强烈的高山地区日益普遍。在这项研究中，选择位于青藏高原腹地的长江上游（UYZ）来评估WRSV的时空变化，预测未来的WRSV并确定WRSV的主要影响因素。WRSV 的时空变化是根据包括敏感性、暴露、危害和适应性在内的框架估计的，该框架考虑了自然和人类活动对 WRSV 的影响。此外，基于SPHY（Spatial Processes in Hydrology）模型、GCMs（General Circulation Models）和归因分析，得到了WRSV的主要影响因素及其未来演变。2001-2019 年 UYZ 的平均 WRSV 对应于中低等级。总体而言，下游地区的WRSV值和增长趋势均高于上游地区。在全球升温1.5°C和2°C的各种情景（SSP 1-2.6、SSP2-4.5、SSP3-7.0和SSP5-8.5）下，平均WRSV将继续处于中低等级。但流域平均WRSV、中脆弱度和中高脆弱度面积比将增加。作为主要影响因素，在历史和未来时期，危害水平对WRSV变化的贡献超过93%。结果表明，气候变化可能会增加乌云带的水资源SV，需要采取适当的对策来更好地应对气候变化对水资源系统的影响。