洞庭湖洪水空间分布和运动特征分析

 鉴于目前仍缺少有关洪水涨落在湖泊中空间分布及其演进的运动特征研究，以1998年洞庭湖洪水事件为例，运用洞庭湖地区水系水动力学模型模拟成果，细致地分析了洞庭湖三大主要湖区的洪水分布形态和运动特征，并对江湖窜流形成进行了初步分析。模拟成果表明：洞庭湖具有“低水河相、高水湖相”的特征；其东、南两个湖区在高洪水位时期湖相特征突出，湖区流向单一，流速不大于0.2 m/s；西洞庭湖区由于各股水流交汇、不同的洪水组合以及出口的制约，致使湖区产生流态复杂、流向不一以及洪峰叠加等现象。  

Analysis of Flood Characteristic in Dongting Lake Using 2-D Hydrodynamic Model

Dongting Lake takes on the functions of regulating,diverting and storing excess flood and is the vital area for the Yangtze River flood control construction.At present,there are lots of studies on the flood routing in middle reach of the Yangtze River.Although it is also included in them, no attention is paid to flood routing in Dongting Lake to analyse its the complexity.The flood characteristic was analyzed based on the Dongting(Lake's) flood event in 1998,using coupling hydrodynamic model with 1-D and 2-D for Dongting Lake area.Both the characteristic of water surface and flow fields show the changes of Dongting Lake from river-like at low water elevation to lake-like at high.The obvious differences in hydrology and hydraulics between both the east and south two lake areas and the west lake area are presented.