黄河上游巴彦高勒至头道拐河段输沙优化调控研究

Study on sediment transport optimal regulation on the reach from Bayangaole to Toudaoguai in the Upper Yellow River

近年来黄河上游宁蒙河段主槽淤积,中小流量下水位明显抬高,洪涝灾害频发。通过建立黄河上游巴彦高勒到头道拐河段水沙数学模型,研究了不同水沙条件下该河段的累计排沙比和累计冲淤量,得到了来水来沙条件与输沙效果的相关关系,计算不同流量下优化输沙的临界含沙量。在此基础上,提出了河道输沙效率指标,得到了适合巴彦高勒至头道拐河段输沙的洪水流量与洪水冲沙历时。研究结果表明,巴彦高勒到头道拐河段水库调节宜采用10天作为冲刷的单位时间,即每次冲刷时间控制为10天,汛期采用多次冲刷,河道输沙效果较好。

Main channel of the Yellow River in Inner Mongolia reach is heavy silting in recent years,and the water level raised obviously during middle or small flow discharge,and the flood disasters take place frequently.In this paper,the water and sediment numerical model is established for study the reach from Bayangaole to Toudaoguai in the Yellow River.The cumulative sediment delivery rate and the cumulative erosion and deposition amount of the river under different water and sediment conditions are studied by the model.Besides,the relationship between the incoming water and sediment and sediment transport efficiency is established to calculate the critical sediment concentration under different flow discharge.Finally,the index of river sediment transport efficiency was provided,for the suitable flood discharge and flood duration from the Bayangaole to Toudaoguai reach.Results show that the flushing period should be 10 days in Bayangaole to Toudaoguai reach during the reservoir operation.