基于理论模型计算的某河道防洪区泥沙冲淤分析研究

Analysis on Sediment Erosion and Deposition of A Riverway Flood Control Area based on Theoretical Model Calculation

根据某河流防洪区内上下游闸坝口断面数据,利用泥沙理论模型,研究了模型中各参数的率定与验证,并获得了上下游闸坝口河道断面泥沙冲淤计算参数结果。获得了上游闸坝口河道断面内高程长期稳定在365.0~380 m,下游闸坝口断面高程集中在362.37~368.77 m,上下游闸坝口现状河道在纵剖面上近乎无显著变化。获得了上、下游闸坝口河道断面内累计冲淤量稳定,年排沙比均在99%以上,上游闸坝口泥沙淤积累计量正值最大为44.33万m^(3),下游闸坝口相比泥沙淤积累计量有所减少,最大值仅有15.8万m^(3);上、下游闸坝口库容分别减少了56.8%、35%,10 a年限后库容分别为625万、149.2万m^(3)。研究了不同频率洪水条件下水面线与深泓线在河道断面的走向。这为河道泥沙冲淤分析提供一定的参考依据。

Based on the cross section data of upstream and downstream sluice and dam in a flood control area of a river,the calibration and verification of the parameters in the model are studied by using the sediment theoretical model,and the calculated parameters of sediment erosion and deposition in the channel cross section of upstream and downstream sluice and dam are obtained.It is obtained that the elevation of upstream sluice and dam mouth section is stable at 365.0~380 m for a long time,while the elevation of downstream sluice and dam mouth section is concentrated at 362.37~368.77 m,and the present river channel of upstream and downstream sluice and dam mouth has almost no significant change in longitudinal profile.The accumulative sediment volume in the upstream and downstream sluice and dam mouth sections is stable,with the annual sand discharge ratio above 99%.The upstream sluice and dam mouth sediment accumulation value is at most 443,300 m3,while the downstream sluice and dam mouth sediment accumulation value is reduced to a maximum of 158,000 m3.The upstream and downstream storage capacity of sluice and dam has been reduced by 56.8%and 35%respectively.10 years later,the storage capacity is 6.25 million m3 and 1.492 million m^(3) respectively.The trend of the water surface profile and the thalweg profile different frequency flood levels in the river section is studied.This paper provides a reference for the analysis of sediment erosion and deposition in the river.