关于三峡水库泥沙计算可靠性的讨论

Discussion on the reliability of sediment computations employed in the feasibility studies of Three Gorges Project

本文通过天然资料等分析 ,讨论了三峡论证期间的水库泥沙数学模型计算的可靠性。提出当时采用的挟沙力系数有偏大倾向。同时 ,当时在用丹江口水库资料验证三峡数学模型时 ,计算淤积量也呈偏少趋势 ,这似与挟沙力系数偏大有关。若减小挟沙力系数 ,三峡水库泥沙淤积将大量增加 ,对通航、防洪和移民可能带来不利影响。尽管在三峡上游即将建设梯级水库 ,上游拦沙对缓解三峡水库淤积有利 ,但考虑到泥沙计算中存在较多不确定因素 ,抓紧利用三峡蓄水后的泥沙观测检验数学模型 ,使三峡工程渐进稳妥发挥其最大效益 ;同时 ,抓紧研究水库优化调度措施 ,减少泥沙淤积、增加防洪能力仍是十分必要的。

The reliability of the deposition results predicted by some earlier models for the Three Gorges Project (TCP) is discussed in this paper. It seems that according to data from natural rivers, the coefficient of sediment transport capacity is over estimated by the models. It also brings evidence by analyzing the validation of the models by the data from the Danjiangkou reservoir. In that validation, the computed depositions are obviously less than the measured. The said coefficient is one of the basic properties for the sediment models used in the feasibility study of TGP, but its sensitivity was not studied during that time. Now the TGP already starts its preliminary impoundment and can carry out more verification with the measured data from TGP itself. Further studies to optimize the operation schemes of the project for less deposition is highly required.