摘要
为识别气候变化背景下极端降雨特征,基于极端降雨事件发生概率小、降雨强度大等特点,构建了年最大降雨和超阈值极端降雨的联合样本序列,采用广义极值分布、伽马分布、正态分布等多分布函数进行拟合,优选分布函数后计算降雨重现期。应用该方法对淮河流域2003年和2007年两次暴雨洪灾事件中日降雨重现期进行了较为准确的计算,并对重现期进行空间插值,识别引发重大洪灾事件时极端降雨的时空分布特征。结果表明:淮河流域2007年7月8日降雨重现期达到了195 a,日降雨极端性最强;2003年最大降雨重重现期为132 a,其他日期均在10 a以下,降雨覆盖面更广。两次洪灾事件中降雨特征较为鲜明;针对不同特征洪灾应采用相应的防灾和减灾措施,最大程度减少灾害损失。该方法充分利用了极端降雨信息,识别了极端降雨分布特征,加深了对极端降雨诱发重大洪灾的认识,可为防洪减灾策略制定提供参考。
In order to identify the characteristics of extreme rainfall under the background of climate change, a joint sample series of annual maximum rainfall and extreme rainfall exceeding threshold was constructed based on the characteristics of rare occurrence, low probability and high rainfall intensity of extreme rainfall events.What’s more, the combined series were fitted by multiple distribution functions such as Generalized Extreme Value(GEV), Gama distribution and normal distribution, and an optimal distribution function was selected to accurately calculate return periods of extreme rainfall.Then the return periods of two heavy rain and flood events in 2003 and 2007 in the Huaihe River Basin were calculated accurately by established method, and the spatial interpolation of the return periods was used to identify the spatial and temporal distribution characteristics of extreme rainfall during the major flood events.The results showed that on July 8, 2007, the rainfall return period in the Huaihe River Basin reached 195-year, with the strongest daily rainfall extremes;in 2003, the maximum rainfall return period was 132-year, and other dates were less than 10-year, so the rainfall coverage was wider.The rainfall characteristics of the two flood events were more distinct, so it is suggested that the corresponding disaster prevention and mitigation measures should be adopted according to different characteristics of floods to minimize disaster losses.The proposed method makes full use of extreme rainfall information and identifies the distribution characteristics of extreme rainfalls, thus it deepens the understanding on severe flood disasters, which can support making strategies of flood prevention and mitigation.
作者
任玉峰
汤正阳
杨旭
华小军
刘新波
REN Yufeng;TANG Zhengyang;YANG Xu;HUA Xiaojun;LIU Xinbo(Three Gorges Cascade Dispatch&Communication Center,Yichang 443002,China;Hubei Key Laboratory of Intelligent Yangtze and Hydroelectric Science,Yichang 443002,China)
出处
《人民长江》
北大核心
2022年第10期65-70,共6页
Yangtze River
基金
长江水科学联合基金项目“基于水位波动的水库支流库湾富营养化和藻类水华的生态调度研究”(U2040210)。
关键词
极端降雨
气候变化
重现期
联合样本序列
分布函数
淮河流域
extreme rainfall
climate change
return period
combined sample series
distribution function
Huaihe River Basin
