从水库形态和调度方式看三峡工程泥沙处置

A Comparative study of TGP's sediment handling

水库形态及水库调度方式对于水利工程的泥沙处置有显著的影响。一些库容相对很大而入库泥沙量相对不大的水库通常按“蓄水拦沙”方式运用，不专门控制泥沙。入库泥沙量相对很大的水库则需要选择合适的调度方式和（或）有效的工程措施来控制泥沙：改建后的三门峡水库采用“蓄清排浑”的调度方式，葛洲坝工程顺应河势布置多种防淤冲沙建筑物，都成功地控制了泥沙。在比较世界上有代表性的几座大水库的形态、特征、调度方式、设计和运行的实践经验的基础上，分析了三峡水库“蓄清排浑”使泥沙淤冲经历七八十年以上才趋近平衡的特点；认为要考虑上游金沙江建库对三峡工程泥沙问题的影响，提出了关于泥沙航运问题论证与决策的看法。

Reservoirs’configuration as well as modes of operation affect sediment handling for hydraulic engineering projects. Many reservoirs with relatively large storage capacity and small amount of incoming sediment usually operate to trap sediment during storing up water without special control while reservoirs with large amount of incoming sediment have to operate according to a specifically defined mode of operation and/or to work with specially designed structures for sediment control. Sanmenxia reservoir has been reconstructed for storing clear water and releasing muddy water,and Gezhouba project has a variety of structures (dykes,sills, bottom outlets, and flushing sluices) for handling sediment in accordance with fluvial characteristics;both successfully operate with little sediment trouble. A comparative study of several large reservoirs in the handling experience is presented in this paper. The configuration and operation peculiarities of the Three Gorges reservoir and the long-term evolution of sedimentation have been analysed. The impact of planned upper Jinshajiang reservoirs on Three Gorges reservoir sedimentation and measures of sediment control ensuring navigation are also discussed.