长江中游的防洪问题和对策--1998年长江特大洪灾的启示

对1998年长江中游特大洪灾分析表明:长江中上游植被破坏,中游湖泊萎缩,干堤防洪标准低,河道泄洪不畅,是洪灾形成的主要因素.三峡水库是长江中游防洪体系中的骨干工程,必须与其他工程相配合.长江中游防洪减灾工程应坚持:(1)与环境保护相结合的原则;(2)与农田水利基本建设相结合的原则;(3)"固、蓄、疏"并举,以"疏"为主的原则;(4)防洪与除渍相结合的原则;(5)统一管理、联合攻关、综合整治的原则与对策.建议除加固长江干堤外,重点建设两条分洪河道,建好3个梯级蓄洪区,有计划有步骤地实施开堤开垸放淤工程.

PROBLEMS AND STRATEGIES FOR FLOOD CONTROL OF MIDDLE REACHES OF YANGTZE RIVER: REFLECTION ON CATASTROPHIC FLOOD OF YANGTZE RIVER IN 1998

Thecatastrophic flood of the Yangtze River in 1998 resulted mainly from the destruction ofthe vegetation in the middle and upper reaches of the Yangtze River, from the shrinkage ofthe lakes in the middle reaches of the Yangtze River, from the low flood-control capacitystandard for the building of the main dikes, and from the smaller flood discharge rate ofthe main channel. The Three Gorges reservoir project, a backbone project in theflood-control system in the middle reaches of the Yangtze River, must match other waterconservancy projects in the same reaches. The following five principles should be adoptedfor the flood-control and hazard-reduction water conservancy projects in the middlereaches of the Yangtze River (1) The building projects for the flood control and hazardreduction should be combined with the environmental protection. (2) The building projectsshould be combined with the capital construction on farms and water conservancy. (3) Thebuilding projects should center around the discharge of the flood, with thecontemporaneous implementation of the dike consolidation, flood storage, and flooddischarge. (4) The flood control should be combined with the flood discharge. (5) Aunified administration should be created for the management of the joint key projects andfor the comprehensive reconstruction. It is suggested in this paper that the main dikes ofthe Yangtze River should be consolidated, two river channels for the flood dischargeshould be built, three step-like flood storage zones should be constructed, and the flooddischarge projects should be carried out through opening dikes and cofferdams to drainaway the silt of channel into the polder as planned.