水利水电技术（中英文）

【目的】为分析全球变暖背景下中国大陆历史和未来不同排放情景下极端降水事件的变化特征，研究我国不同地区极端降水事件频率和强度的变化规律。【方法】选取日尺度历史降水数据(1979—2021年)和CMIP6未来情景模式降水数据(2015—2100年),使用Mann-Kendall检验等方法，分析历史和未来低(SSP1-2.6)、中低(SSP2-4.5)、中高(SSP3-7.0)和高(SSP5-8.5)排放情景下极端降水的时空变化趋势。【结果】结果表明：1979—2021年，我国各区域极端降水指数呈现东高西低的空间格局，连续干旱日数(CDD)、雨日日数(RD)在全国范围内呈下降趋势，其他极端降水量指数(如最大1 d降水量Rx1day)和日数指数(如大雨日数R25)等均为上升趋势，其中华东、华南和西南地区趋势最显著。未来不同时期，极端降水日、量数指数在不同经济路径下变化趋势亦有差异，2045—2075年上升面积占比增幅最大；华东地区在SSP3-7.0路径下极端降水量上升幅度最大，华南地区在SSP2-4.5路径下极端降水日指数上升面积最小，华北、西北和东北地区极端降水量指数随排放升高规律变化，西南地区受排放升高影响极端降水量指数上升面积占比最高。【结论】历史数据表明，我国极端降水事件频率与降水强度有增加趋势。未来情景模式4种经济路径下，全国范围内极端降水强度增加的面积占比有不同程度增加，本世纪后期(2060—2100年)面积占比变化趋于稳定。华中、东北、西北和西南青藏高原及其周边地区随排放升高极端降水事件发生频率与降水强度增加。不同地区极端降水对排放升高的响应有明显的区域差异，华北、东北和西北地区响应程度相近且规律性增加，华中、西南地区响应程度相近但无规律变化，华东和华南地区响应程度接近且强度升高面积占比接近于1。

[Objective]In order to analyze the change characteristics of extreme precipitation events in Chinese mainland under different historical and future emission scenarios under the background of global warming, and to study the change law of frequency and intensity of extreme precipitation events in different regions of China, [Methods]Historical precipitation data of daily scale(1979—2021) and precipitation data of CMIP6 future scenario model(2015—2100) were selected. Using Mann-Kendall test and other method, the spatial and temporal trends of extreme precipitation under historical and future low(SSP1-2.6), medium low(SSP2-4.5), medium high(SSP3-7.0) and high(SSP5-8.5) emission scenarios were analyzed.[Results]The result show that: From 1979 to 2021, the extreme precipitation index in all regions of China presents a spatial pattern of high in the east and low in the west, and the number of consecutive dry days(CDD) and rainy days(RD) show a downward trend nationwide, while other extreme precipitation indexes(such as the maximum 1 d precipitation Rx1day) and the number of days(such as the number of heavy rain days R25) show an upward trend. The trend is most significant in East, South and Southwest China.In the future, the change trend of extreme precipitation day and quantity index will also be different under different economic paths, and the proportion of rising area will increase the most from 2045 to 2075. Under the SSP3-7.0 path, the increase of extreme precipitation in East China is the largest, and the increase area of extreme precipitation daily index in South China is the smallest under the SSP2-4.5 path. The extreme precipitation index in North China, Northwest and Northeast China changes with the increase of emission, and the increase area of extreme precipitation index affected by the increase of emission is the highest in southwest China.[Conclusion]The historical data show that the frequency and intensity of extreme precipitation events in China have an increasing trend. Under the four economic paths of the future scenario model, the area proportion of the increase of extreme precipitation intensity in the whole country has increased to different degrees, and the change of the area proportion tends to be stable in the later part of this century(2060—2100).In central China, Northeast China, Northwest China and Southwest Tibet Plateau and its surrounding areas, the frequency and intensity of extreme precipitation events increased with the increase of emission. There are obvious regional differences in the response of extreme precipitation to emission increase in different regions. The response degree of extreme precipitation in North China, Northeast China and Northwest China is similar and increases regularly; the response degree of extreme precipitation in central China and Southwest China is similar but changes irregularly; the response degree of extreme precipitation in East China and South China is similar and the proportion of area with intensity increase is close to 1.