梅雨雨带移动对1961-2020年江苏省极端降水的影响

Influence of Meiyu Belt movement on the extreme precipitation in Jiangsu Province from 1961 to 2020

极端降水的气候态特征及其演变对于城市内涝防控、水环境污染治理、海绵城市建设等意义重大。利用江苏省67个国家级气象观测站1961-2020年的日降水资料,采用趋势分析、M-K检验、小波分析等方法分析强降水和极强降水的气候态特征和年代际变化,以及梅雨雨带移动对江苏省内淮河流域和长江流域极端降水的影响。结果表明:江苏省沿江地区强降水和极强降水的雨量最大。强降水和极强降水分别贡献了全年34.5%和11.9%的降水量,1/3的极端降水发生在6月下旬至7月中旬。江苏省大部分地区的极端降水雨量、雨日和雨强呈增加趋势,但只有长江流域通过显著性检验。极端降水的雨强年代际波动较小,雨量年代际波动较大;年代际波动性与其平均态之间无显著的对应关系。梅雨雨带的南北移动对极端降水产生明显影响,江苏省内的长江流域和淮河流域的年降水异常度和强降水距平百分率对应关系较好,在降水异常偏多年份发生极端降水的概率较高。江苏省内长江流域和淮河流域近60年的强降水多次出现增加、减少的变化。2010年以后长江流域极端降水增多,雨量和雨日上升趋势显著,开始时间明显提前,结束时间推后,持续时间增长。

The climatic characteristics and evolution of extreme precipitation are of great significance to the prevention and control of urban waterlogging,water environmental pollution control,and the construction of sponge cities.Based on the daily precipitation data from 67 national meteorological observatories in Jiangsu Province from 1961 to 2020,the trend analysis,Mann-Kendall test and wavelet analysis are used to analyze the temporal and spatial distribution characteristics and changing trends of heavy and extremely heavy precipitation,as well as the effects of the Meiyu Belt movement on extreme precipitation in the Huai River Basin and the Yangtze River Basin.The results show that the area along the Yangtze River had the largest amount of precipitation.Heavy precipitation and extremely heavy precipitation contributed 34.5%and 11.9%of the annual precipitation,respectively,and one-third of the extreme precipitation events occurred from late June to mid-July.In most areas of Jiangsu Province,extreme precipitation,rainy days and rainfall intensity showed an increasing trend,but only the increasing trend of the Yangtze River Basin passed the significance test.The inter-decadal rain intensity of extreme precipitation fluctuated slightly,whereas the inter-decadal rainfall fluctuated greatly;however,there is no significant correspondence between the inter-decadal fluctuations and the average state of extreme precipitation.The north-south movement of the Meiyu belt had a significant impact on extreme precipitation.In the Yangtze River Basin and the Huaihe River Basin in Jiangsu area,the annual precipitation anomalies were associated with strong precipitation,so in the year of abnormally high precipitation,the probability of extreme precipitation events was relatively high.The heavy rainfall in the Yangtze River Basin and the Huaihe River Basin in Jiangsu area have increased and decreased many times during recent 60 years.After 2010,extreme precipitation events started to increase,with a significant increment in rainfall and rainy days in the Yangtze River Basin,most of which started early but finished late with a prolonged duration.