变化环境下，嘉陵江流域水循环过程呈现出新的变化特征且极端水文事件发生频率增加，对社会生产和生活造成极大威胁。因此，亟待开展揭示气候和人类活动影响下流域水循环转化相互作用机理，探明各水循环要素及极端水文事件的分布格局及演变趋势的研究。本项目拟分析流域水循环和极端水文事件多尺度演变规律及其空间分异；运用Lasso回归法、Budyko方程和SWAT模型，定量评估气候变化和人类活动对径流和极端水文事件的相对贡献，同时，利用多元分析、EOF分解及正交小波分析法，辨识不同尺度极端水文事件的形成原因；进一步，利用统计-动力结合的降尺度方法，对ISI-MIP降水数据进行偏差校正，开展1.5℃、2.0℃升温情景下水循环及极端水文事件演变预估及多模型对比分析。研究成果有助于深入认识变化环境下水循环及极端水文事件的多尺度作用机理及演变规律，为嘉陵江流域水资源综合规划、洪涝干旱灾害预警提供理论依据和科学指导。

Under the changing environment, the water cycle process in the Jialing River Basin presents new changes and the frequency of extreme hydrological events increases, posing a great threat to social production and life. Therefore, it is urgent to carry out research on the interaction mechanism of water cycle transformation under the influence of climate change and human activities, and to explore the distribution patterns and evolution trends of water cycle elements and extreme hydrological events. The project aims to analyze the multi-scale evolution rules and spatial differentiation of the watershed water cycle and extreme hydrological events firstly. Then, Lasso regression, Budyko hydrothermal equilibrium equation and SWAT model were used to quantitatively assess the relative contributions of climate change and human activities to runoff and extreme hydrological events in different historical periods. At the same time, the multi-analysis, EOF decomposition method and orthogonal wavelet analysis method are used to analyze the formation of extreme floods and extreme dryness at different scales in different historical periods. Finally, deviation correction was performed on the ISI-MIP precipitation data using a statistical-dynamic combined downscaling method，and the water cycle and extreme hydrological event evolution prediction and multi-model comparison analysis were carried out under the 1.5°C and 2.0°C global warming targets. The research results will help to understand the multi-scale mechanism and evolution of water cycle and extreme hydrological events in a changing environment, and provide theoretical basis and scientific guidance for comprehensive water resources planning, flood control and drought warning in the Jialing River Basin.