:洞庭湖区从 1995年到 1999年间有 4年发生特大洪水 ,大小共计几十个堤垸漫溃或溃决。 1999年 7月益阳民主垸溃决后 ,长江委水文部门组织施测了从溃口开始到堵口复堤期间长达 90多天的水位、流量、溃口地形、河床地质等资料。通过大量实测数据 ,结合附近基本文站网的历史资料 ,把民主垸溃决作为一次分洪溃口的试验模型 ,对民主垸的入出流过程、入垸总水量、垸内隔堤的作用、资水中下游河段水位降低幅度及出险成因等方面进行了分析 ,为资水河的规划整治以及长江分洪演算提供可靠成果 : Dongting Lake area from 1995 to 1999, there have been four years of extraordinary floods, the total size of dozens of embankments collapse or collapse. In July 1999, after the democratization of Yiyang Democratically, the hydrological department of the Yangtze River Commission conducted a survey on the water level, the flow rate, the topography of the crumpled mouth and the riverbed geology during the period from the breach to the embankment embankment. Through a large number of measured data, combined with the historical data near the basic station network, the democratic embankment as a pilot flood diversion test model, the embankment of the inflow and outflow process, into the embankment total water, embankment within the embankment role, middle and lower reaches of water River level and the reasons for the risk of the emergence of a risk analysis for the planning and treatment of the river water and the Yangtze River flood diversion calculus provide reliable results