泥沙模型时间变态影响消减措施探讨

针对长江中下游河段泥沙模型时间变态影响及其消减措施的问题，通过回顾以往相关研究工作，分析了时间变态成因及其影响，并评述了消除或减弱泥沙模型时间变态影响的有关措施或设想。在此基础上，以长江南京河段泥沙模型为实例，基于调整模型水沙过程概化方式的思路，进行了消减时间变态影响的试验研究。结果表明:按水沙过程逐日平均概化方式进行泥沙试验基本可行，有望在长河段模型试验中解决或改善时间变态所带来的涨水水量不足和落水水量排除的难题。

On improvement measures of time scale distortion in sediment model tests

Aiming at the improvement measures of time scale distortion in the sediment model test for the middle-lower reaches of the Yangtze River, by reviewing the previous related research findings, the causes of the time scale distortion and its adverse impacts on the similarity of flow and sediment movement in the sediment models are analyzed in this study, and some relevant improving measures or assumptions for eliminating or mitigating the time scale distortion of the sediment models are reviewed. Then, by means of the case study of the model tests on the Nanjing reach of the Yangtze River, based on the adjustments of the generalized mode of the model water and sediment process, the studies of the improvement measures of the time scale distortion are carried out in this paper. The analysis results show that it is feasible to carry out the sediment tests according to the daily average generalized mode in the model water and sediment process. It is expected to solve or improve the difficult problems on water shortage in the rising period and water drainage in the falling period caused by the time scale distortion in the sediment model (especially for the long reach model) tests.