不同关键期长江上游与洞庭湖洪水遭遇过程气候特征对比

Climatic Features Comparison of Flood Encounter Processes During Different Critical Stages for Upper Reaches of the Yangtze River and Dongting Lake

长江上游与洞庭湖一旦遭遇洪水,将会形成全流域洪水或特大洪水,给防洪减灾带来巨大考验。从大尺度环流背景、天气系统特征以及物理量场特征3个角度出发,对1981—2012年共30次长江上游洪水与洞庭湖洪水遭遇过程进行分析,总结出消落期、汛期、蓄水期3个不同关键期内发生洪水遭遇的不同气候特征,提出面上物理量和面上综合指数的新概念。

Flood from the upper reaches of the Yangtze River and Dongting Lake encountering is the main reason of the whole basin flood and serious flood, which produced huge pressure for flood control and disaster reduction. The climate characteristics were summarized about flood encounter processes during three periods including falling stage, flood season and impounding period from the large scale circulation background, synoptic system and physical quantity field characteristics by analyzing 30 flood encounter processes from 1981 to 2012. In addition, new conceptions about regional physical quantity and composite index were presented. This research was helpful to deeply understand encounter regularity of flood in the upper reaches of the Yangtze River and Dongting Lake, which provided a good technical support for optimizing the regulation scheme of the Three Gorges Project.