关于长江中游洪灾问题的思考

THINKING ON THE FLOOD DISASTER IN THE MIDDLE REACHES OF THE YANGTZE RIVER

中国是一个水灾频发的国家 ,长江中游历来就是重灾区。 1998年的长江洪水是 1954年以来最大的一次全流域性洪水 ,高水位持续时间长 ,洪水量大 ,洪水遭遇情况恶劣是这次长江汛期的突出特点 ,由此造成的损失十分严重。导致长江中游洪灾的原因是众多的 ,其中气候异常是最直接的影响因素 ,但过度围湖垦殖与江湖关系失调亦是洪涝灾害日趋严重的一个重要原因。由于自然演变和人类活动的共同作用 ,长江中游河湖环境越来越不利于超额洪水的排泄。江汉湖群、洞庭湖和鄱阳湖面积缩小 ,容积减少 ,对河流水量的调蓄作用大大降低。同时荆江已演变为典型的弯曲河道 ,成为防洪的重点地段。荆江大堤的修建隔断了江湖联系 ,改变了中游河湖关系。所有这些因素都使得中游洪灾日益加重。为了实现区域可持续发展 ,迫切需要建立一套完善的抗洪减灾防御体系。

The Middle Reaches of the Yangtze River has long been the most severe flood region in China. The author analyzes the brief history of flood hazard in this area and the features of the great flood in 1998. Many factors, such as the abnormal climate,and the breakdown of eco\|environment,and the backwardness of hydrological facilities aggravate the flood hazard. But the river\|lake environment is also an important factor. Owing to be offensive to the natural evolution law and the unreasonable human activity, the river\|lake environment has become more and more unfavorable for the drainage and distribution of the flood water. The Jianhan Lake and the Dongting Lake and the Poyang Lake have shrunk greatly during the historical period.The Jinjiang has developed into a meandering river. Due to the construction of the Jinjiang dikes, the Jinjiang has changed significantly the relationship between the river and the lake. All of these have decreased the capability controlling the flood in this area. In order to realize the sustainable development, some countermeasures are urgently needed and the system of flood\|fighting and damage\|mitigation in the Middle Reaches of Yangtze River should be set up.