极端气候加剧下塔里木河“四源”未来洪水风险预估及其适应性研究

极端气候加剧下的洪水风险问题是目前国际上气候变化领域的重大科学问题。塔里木河（简称“塔河”）流域具有雨、雪、冰“三元”产流的特点，洪水类型多样且对气候变化十分敏感。近年来，极端气候加剧引发的洪水风险增加严重威胁当地人民的生命和财产安全，开展塔河流域极端气候变化对洪水的影响机制及未来洪水风险评估研究意义重大。本项目选择塔河“四源”为研究区，采用GIS技术、耦合改进的SWAT模型与FloodArea水动力学模型、随机森林等方法，解析近30年塔河“四源”不同类型洪水时空演变特征，识别并量化极端气候主控因子对不同类型洪水过程的贡献；构建洪水风险动态评估模型，预估不同气候情景下塔河“四源”洪水风险的时空动态格局，在此基础上提出应对洪水风险的适应性对策和建议。研究结果可为高寒山区流域防灾减灾和气候变化适应性对策的提出提供科学依据和理论支撑。

The four source streams of the Tarim River have the characteristics of “three-source (rainfall, snow and ice)” runoff generation, and their hydrological processes are significantly affected by climate change. The increased risk of flood due to the intensified extreme climate poses a serious threat to the lives and property of local people. This study was based on the processes and risks of floods in the four source streams of the Tarim River and the spatial analysis techniques of GIS, the coupling of improved SWAT and FloodArea hydrodynamic model, and random forest were used. The objectives of this research are: i) interpreting the spatiotemporal evolution characteristics of different types of floods in these four streams, and exploring the key extreme climatic factors affecting different types of flood processes. ii) constructing dynamic assessment model for different types of flood risks; iii) predicting the spatiotemporal dynamic patterns of future flood risks in the four source streams under different scenarios, and on this basis, proposing adaptive countermeasures and suggestions for the coping with further flood risks in the Tarim River Basin under the background of intensified extreme climate. The study is based on a new perspective of dynamic assessment of flood risk and enriches the research methodology of flood risk prediction. The results of this study provide a scientific and theoretical basis for the prevention and mitigation of flood and rational allocation of water resources in the alpine mountainous basin.