2016和2020年梅雨期太湖超标洪水气象水文特征分析
Hydrometeorological characteristics of plum season for the Taihu exceeding-standard floods in 2016 and 2020
投稿时间:2020-12-08  修订日期:2020-12-08
DOI:
中文关键词:  太湖超标洪水  梅雨期  天气形势  核心汇流区
英文关键词:Taihu exceeding-standard flood  plum season  atmospheric circulation  core flow concentration area
基金项目:国家重点研发计划项目
作者单位邮编
吴娟 太湖流域管理局水文局(信息中心) 200434
施春红 上海中心气象台 
林荷娟 太湖流域管理局水文局(信息中心) 
邹兰军 上海中心气象台 
杨雅薇 上海市气候中心
 
季同德 太湖流域管理局水文局(信息中心) 
薛涛 太湖流域管理局水文局(信息中心) 
摘要点击次数: 86
全文下载次数: 0
中文摘要:
      基于太湖流域逐日报汛降水量、NCEP/NCAR逐日大气再分析等资料,对比分析了2016年和2020年梅雨期太湖超标洪水气象水文特征。结果表明:(1)2016年、2020年梅雨量分别为412.0mm、583.8mm,太湖最高水位分别为4.87m、4.79m;对于各个时段极值降水量及重现期,2016年北部湖西区、武澄锡虞区较高,2020年南部浙西区、杭嘉湖区较高。(2)梅雨期大气环流共同点为:前期热带印度洋海温异常偏暖,导致副高偏强、西伸脊点偏西,中高纬度经向环流发展,有利于来自南海的偏南气流、印度洋经孟加拉湾的西南气流与北方弱冷空气相结合,导致梅雨量异常偏多;不同点在于,2016年副高脊线6月中下旬北跳以后位置相对稳定,雨带主要集中在流域北部,2020年副高脊线6月初北跳以后南北摆动幅度较大,流域南北分区交替出现暴雨过程。(3)两年太湖超标洪水形成原因不同,2016年由异常偏高的入梅水位叠加核心汇流区集中强降水形成,而2020年太湖高水位则由异常偏长的梅雨期、核心汇流区降水总量大共同形成。
英文摘要:
      Based on daily precipitation from flood reporting stations, reanalysis atmospheric data from NCEP/NCAR, we have conducted a comparative analysis of the hydrometeorological characteristics for Taihu exceeding-standard floods between 2016 and 2020. The results demonstrated that (1) the accumulated precipitation of the plum season in 2016, 2020 was 412.0 mm, 583.8mm, respectively, while the highest Taihu water stage of the two years was 4.87m, 4.79m, respectively. The extreme precipitation and return period in 2016 was higher in the northern part of the Taihu Basin (the Huxi and Wuchengxiyu sub-region), while the extreme precipitation and return period in 2020 was higher in the southern part (the Zhexi and Hangjiahu sub-region). There are many similarities in the atmospheric circulation characteristics during the plum season. (2) The strong warming in tropical Indian Ocean in the preceding seasons lead to stronger than normal and more westward-extending west Pacific subtropical high (WPSH). The radial circulation situation was conducive to the warm moisture transport from South China Sea, and the warm moisture transport from Indian Ocean via the Bay of Bengal, interacting with cold air from the north in the Taihu basin. The WPSH jumped northward in Mid-late June of 2016 and kept stable, and the heavy precipitation mainly occurred in the northern part of Taihu Basin. However, the WPSH jumped northward in early June of 2020, and the north-south swing of WPSH was larger, resulting in north-south swing of heavy precipitation occurrence in the Taihu Basin. (3) The significant high Taihu water stage on Meiyu onset date, as well as the persistent heavy rainfall in core flow concentration area are main reasons for the Taihu exceeding-standard flood in 2016. Nevertheless, the significant long Meiyu length and more precipitation in core flow concentration area are main reasons for the Taihu exceeding-standard flood in 2020.
  查看/发表评论  下载PDF阅读器