洞庭湖蓄洪能力讨论

ON THE CAPACITY OF FLOOD STORAGE IN DONGTING LAKE

洞庭湖蓄洪能力具有重要的意义。首先，洞庭湖是湘、资、沅、澧四水洪峰的汇流中心，它的蓄洪能力直接关系到缓和洞庭湖自身流域的洪峰压力。其次，作为长江的支流湖，洞庭湖的蓄洪能力也间接关系到长江流域的蓄水系数，从而关系到缓和长江下游的洪水水位。在洞庭湖现有泄流系数不变的情况下，要增加洞庭湖的蓄洪能力，主要靠扩大蓄洪区和加高堤垸防洪高度。由于这两者都存在天然限制，所以不可偏废，只可兼顾。

The capacity of flood storage in Dongting Lake is of great significance. At first,Xiang-Zi-Yuan-Li Rivers are flowing into Dongting Lake,so that the capacity of water storage in Dongting Lake is directly related to the alleviation of flood pressure coming from Xiang-Zi-Yuan-Li Rivers. Meanwhile,Dongting Lake is also a tributary lake of the Yangtze River,and the capacity of water storage in Dongting Lake is related to the coefficient of water storage and the alleviation of flood pressure coming from the whole Yangtze River.Under the same condition of outflow coefficient,to increase the capacity of water storage in Dongting Lake mainly needs to enlarge the area of water-storage and to reinforce or pile up the embankment. As the two methods are confined by certain limit,it is better to combine two of them together .