洞庭湖区防洪问题研究

A Study on Countermeasure of Flood Control in Dongting Lake

自解放以来 ,洞庭湖区围湖垦殖、泥沙淤积 ,湖区面积衰减 172 7km2 。湖容萎缩 12 6亿m3。湖区洪水位抬高 1 0m以上。下荆江裁弯后 ,三口萎缩加速 ,江湖关系发生重大变化 ,长江城螺河段河床淤积 ,水位升高 ,洞庭湖出口泄流不畅 ,湖区洪水位进一步抬升 ,防洪形势严峻 ,洪灾损失严重。解决湖区防洪问题的关键是减少超额洪水来量及降低城陵矶河床高程及水位 ,扩大调洪湖容 ,近期难以实现。采取在退田还湖的同时挖湖筑堤造台 ,提高防洪标准 ,让老百姓安居乐业 ;堵支并流与疏通河道 ,扩大调洪能力 ;实施干支流水库联合调度防洪及预留必要的设施完备的分蓄洪区 ,乃是解决洞庭湖区防洪的当务之急。

Since 1949,due to the sediment deposit and land reclamation, the water surface area and storage capacity in Dongting Lake have shrunk by 1 727km 2 and 126×10 8m 3,respectively.The flood level in Dongting Lake is raised over 1m. The cut\|offs in the lower Jingjiang River made a faster shrinkage of the three mouths in Jingjiang reach to Dongting Lake and caused a significant change of the relationship between the Jingjiang River and Dongting Lake. The deposition in the reach from Chenlingji to Loushan raised the water level at Chenlingji, which is the outlet of Dongting Lake to Yangtze River. As a result, the flood level in Dongting Lake becomes higher and the situation of flood control is very serious. It is difficult in the near future to lower the water level in Chenlingji. Therefore the primary ways to control flood in Dongting Lake should return the farmland to the Lake, raise the dike, and dredge the Lake.