水利水电技术（中英文）

全球变暖背景下多地极端气候事件频发,已成为区域可持续发展的重要影响因素。为了系统诊断中国区域近58年的极端冷暖气温事件的时空演变特征,本文采用1961—2018年中国545个气象站点的日值气温数据,根据WMO推荐的6项极端温度事件指数,即冷昼、冷夜、暖昼、暖夜日数及冷日持续日数和暖日持续日数,从阈值分布、变化趋势、波动特征和持续性特征角度诊断了中国极端温度指标的时空变化特征。结果表明:(1)1961—2018年中国冷暖昼夜气温阈值均呈南高、北低的空间分异特征,且冷昼和冷夜气温阈值在南北地区具有正负分异特征。(2)1961—2018年中国冷昼和冷夜日数主要呈减少趋势,且冷夜日数减少趋势明显大于冷昼日数;暖昼和暖夜日数主要呈增加趋势,且暖夜日数增加趋势明显大于暖昼日数。(3)1961—2018年中国冷昼和冷夜日数波动特征主要呈现南低、北高的空间分异特征,而暖昼和暖夜则恰好相反,主要呈南高、北低的空间分异特征。(4)中国冷日持续日数在1960—1980年代逐渐由南低、北高的空间分异特征演变为南高、北低的空间分异特征。1990—2010年代则由西高、东低的空间分异特征演变为除青藏高原外的全国性的增多态势。暖日持续日数在1960—1980年代在黄淮以南逐渐减少,并向南方转移。1990—2010年代则呈现为全国性的增多态势。(5)1961—2018年中国冷日持续日数主要呈减少趋势,而暖日持续日数则主要呈增加趋势。在波动特征上,西南和北方地区是冷暖持续日数波动普遍偏大的地区。暖日持续日数波动较大的地区明显多于冷日持续日数。研究结果对于认识增暖背景下中国地区的极端温度事件具有参考意义。

Under the background of global warming, many extreme climate events occur frequently, which has become an important factor of regional sustainable development. In order to systematically diagnose the temporal and spatial evolution characteristics of extreme cold and warm climate events in China in recent 58 years, based on the daily temperature data of 545 meteorological stations in China from 1961 to 2018 and 6 extreme cold and warm temperature indices recommended by WMO, i.e., cold days, cold nights, warm days, warm nights, cold duration days and warm duration days, this study diagnosed temporal and spatial variations of exterme temperature indices in China from the view of threshold distribution, variation trend, fluctuation characteristics and duration characteristics. The results showed that:(1) The temperature thresholds of cold and warm days and nights in China from 1961 to 2018 showed the spatial differentiation characteristics of high in the South China and low in the North China, and the temperature thresholds of cold days and cold nights had the positive and negative differentiation characteristics in the North and South China.(2) Cold days and cold nights in China were mainly decreasing, and the decreasing trend of cold nights were obviously greater than that of cold days; the increasing trend of warm days and warm nights were mainly increasing, and the increasing trend of warm nights were obviously greater than that of warm days.(3) The fluctuation characteristics of cold days and cold nights in China from 1961 to 2018 mainly show the spatial differentiation characteristics of low in the South China and high in the North China, while warm days and warm nights were just the opposite, mainly show the spatial differentiation characteristics of high in the South China and low in the North China.(4) The duration of cold days in China gradually changed from low in the South China and high in the North China to high in the South China and low in the North China. The spatial differentiation characteristics of High in the West China and low in the East China change into the national growth trend except for the Qinghai-Tibet Plateau. The duration of warm days gradually decreased in the south of Huanghuai River from 1960 s to 1980 s, and shifted to the South China. It indicated that a nationwide growth trend from 1990 s to 2010 s.(5) The duration of cold days in China were mainly decreasing, while the duration of warm days were mainly increasing from 1961 to 2018. In terms of fluctuation characteristics, the Southwest China and North China were the regions where the fluctuation of the duration of cold and warm days were generally large. The fluctuation of the duration of warm days were more obvious than that in the duration of cold days. The results can be used as a reference for understanding the extreme temperature events in China under the background of global warming