南水北调中线工程水源区干旱情况和水量变化影响着工程调水稳定性，对沿线城市的工业、农业、居民用水等多方面有着重大意义。本文基于1961-2019年气象观测数据和CMIP6模式数据，利用标准化降水蒸散指数（SPEI, Standardized Precipitation Evapotranspiration Index）计算了南水北调水源区和受水区的干旱指数，并利用经验正交分析（EOF, Empirical Orthogonal Function）和Copula函数等方法，对水源去与受水区的干旱演变规律进行分析，揭示了干旱遭遇的联合概率分布，并对未来干旱遭遇进行预估，研究结果表明： ①水源区和受水区干旱事件遭遇频繁，1965-1971和1987-2005年均出现较为严重的干旱遭遇事件，同时在1970年代中后期至1985年前后，出现了长期明显的区域差异性；②水源区和受水区中旱和重旱的联合重现期分别约为18年一遇（5.51%）和123年一遇（0.81%），两地同时出现极端干旱的重现期约为323年一遇（0.31%）；③不同气候情境下的未来干旱事件预估表明，在未来SSP1-2.6情境下主要以非极端干旱为主；在SSP2-4.5情境下2034-2036年以及2044-2045年，水源区和受水区将同时面临严重干旱遭遇；在SSP5-8.5高辐射强迫情境2032-2033年以及2068-2070年，水源区和受水区也会同时面临严重干旱遭遇。

The South-to-North Water Diversion Project is of great strategic significance for improving the national water network and optimizing the overall pattern of water resource allocation. The drought situation and water quantity changes in the source area of the South-to-North Water Diversion Project affect the stability of the water transfer project, and are of great significance to the industrial, agricultural, residential water use and other aspects of the cities along the route. In recent years, there have been more and more research on extreme drought monitoring, and a variety of meteorological hydrological drought index models have been widely used, such as standardized precipitation evapotranspiration index, palmer drought index, standardized precipitation index and so on. The standardized precipitation evapotranspiration index model is superior to the other two drought index models because it takes into account the evapotranspiration factor. Although some research has been conducted in recent years on climate change in the water source or water-receiving areas of the South-North Water Diversion Project, few studies have explored the drought encounters in water source and water-receiving areas in the context of future climate change. By integrating a large number of meteorological observation data and the latest Coupled Model Intercomparison Project Phase 6 climate model data, using standardized precipitation evapotranspiration index, empirical orthogonal function analysis, copula function and other methods, the spatial and temporal distribution of drought in the water source area and the water receiving area of the South-to-North Water Diversion Project in the historical period was calculated. The drought encounter problem in the water source area under different climate scenarios in the future was estimated by using the Coupled Model Intercomparison Project Phase 6 meteorological dataset as the driving data and then provided a theoretical basis for water resources planning and management. Empirical orthogonal function was performed using the calculation results of the standardized precipitation evapotranspiration index and the copula function for the joint probability distribution of drought between water source and water receiving area. Then, the mean Coupled Model Intercomparison Project Phase 6 multi-mode data is used as the input data for future standardized precipitation evapotranspiration index calculations, and the drought comprehensive evaluation is carried out on the water source area of the South-North Water Diversion Project. Results showed that drought events in water-source areas and water-receiving areas were frequent, with more serious drought encounters in 1965-1971 and 1987-2005, and long-term obvious regional differences from the mid-to-late 1970s to around 1985. The combined recurrence periods of drought and severe drought in water-source areas and water-receiving areas were about once in 18 years (5.51%) and once in 123 years (0.81%), respectively, and the recurrence period of extreme drought in both places was about once in 323 years (0.31%). The estimation of future drought events in the water source area and the water-receiving area of the South-North Water Diversion Project based on the annual SPEI index under different climatic scenarios shows that the future drought predictions in the future SSP1-2.6 and SSP2-4.5 scenarios in the water source area are comparable, mainly non-extreme drought, with only one extreme drought occurring in 2078, and the continuous drought and flood events in 2068-2070 under the future SSP5-8.5 scenario. Droughts occurred frequently in the 2030-2045 SSP2-4.5 scenario in the water-affected areas, and fewer future drought events occurred in the SSP1-2.6 and SSP5-8.5 scenarios. Water source areas and water-receiving areas mainly experienced long-lasting droughts in the 1930s, 40s, 1960s and 1970s, and there are problems of water diversion risks and difficulties in the future. Both historical and future water sources and water-receiving areas have suffered drought at the same time, so to reduce the risk of water transfer and ensure water supply, it is necessary to provide the utilization value of the South-North Water Diversion Project and better play its benefits.

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国家重点研发计划(2019YFC0409000)；国家自然科学基金面上项目(41971025)Funds: National Development Plan(2019YFC0409000); The General Program (Key Program, Major Research Plan) of National Natural Science Foundation of China(41971025)