典型年洪水的洞庭湖槽蓄特性研究

Research on the Channel Storage Characteristic of the Dongting Lake Based on Typical Year Flood

洞庭湖南连四水、北接四口,其巨大的槽蓄作用和槽蓄特性直接影响了洞庭湖及长江中下游的防洪总体布局和水资源配置方案。采用1995年实测洞庭湖区天然高程~容积关系成果,对洞庭湖区出现大洪水的1991年、1995年、1996年、1998年洪水过程的槽蓄特性进行了分析研究,认为水深增量相同而流量不同时湖泊槽蓄量增量存在差异,故在进行防洪规划时应合理规划防洪水位,最大限度运用洞庭湖调蓄功能;分析比较了地形法和水量平衡法应用于洞庭湖区槽蓄量计算的差异及产生差异的原因。研究成果对长江中下游及洞庭湖区防洪总体布局和水资源配置方案的科学制定具有重要的指导和借鉴意义。

The Dongting Lake connects four rivers in Hunan Province and the four outlets of Jingjiang River. Its huge channel storage capacity and unique channel storage characteristic directly affects the overall layout of flood control of the Dongting Lake and the middle and lower reaches of the Changjiang River. By using the elevation-capacity curve of the Dongting Lake,we analyze the channel storage characteristics of the Dongting Lake based on the lake ＇ s hydrological data in 1991,1995,1996,1998. It is believed that the increment of channel storage capacity has differences when the water depth increment is the same and the discharge is different. Therefore,the flood control level should be rationally planned to make the flood regulation function of the Dongting Lake most efficiently. This paper also compares the differences of channel storage capacity of the Dongting Lake by using the two different methods： geomorphologic method and water balance method and discusses the factors leading to these differences. The research results have important guidance and reference significance for the overall layout of the flood control and water resources allocation scheme in the middle and lower reaches of the Changjiang River and the Dongting Lake.