长江特大洪水原因与防灾方略探讨

’９８长江大洪水波及到长江中下游的湘、鄂、赣、皖、苏５省，受灾面积１３３３万多ｋｍ２，洪水前后持续２个月。发生大洪水的原因，既有天气因素的影响，也有上游森林破坏招致水土流失的作用，还有人为围湖造田带来的负效应的影响，但根本原因是天气因素所致。中下游地区湖泊水面积减小，人为在河道上圈地、设障，是导致洪水水位抬高、险情增加的重要原因。长江综合治理的目标与重点是，上游修建除三峡以外的控制性的调蓄工程群，实行蓄水、减沙与森林生态工程相结合，中下游进行固堤、河道清障，保护现有湖泊的调蓄功能。

Discussions on Causes of the Extraordinary Flood of the Yangtze River and A General Plan of Disaster Prevention

The 1998 extraordinary flood effected 5 provinces of Hunan, Hubei, Jiangxi, Anhui and Jiangsu located on the middle and lower reaches of the Yangtze River with total effected area 1.333 million km 2 and lasting for 2 months. The reason of causing the great flood is not only for the influence of weather factor and influence of soil and water loss caused by the destructed forest in the upper reaches, but also the influence of negative effect brought by man-made enclosing lakes for cultivation. But, the fundamental reason is the influence of weather factor. The reduction of water surface area of lakes located on the middle and lower reaces and enclosing area for cultivation and placing obstacles by people on river are the main reason of increasing the flood level and dangerous situations. The objectives and key points of comprehensive management of the Yangtze River are to build a group of controlling reservoirs in the upper reaches except the Three Gorges Project, combine the measures of storage and sediment reduction with forestry engineering project, strengthen dykes of middle and lower reaches, remove obstacles in the channel and protect the regulating function of the existing lakes as well.