申冠卿, 张原锋, 张敏. 黄河下游漫滩高含沙洪水滩槽界定及泥沙时空沉积特性[J]. 水科学进展, 2017, 28(5): 641-651. DOI: 10.14042/j.cnki.32.1309.2017.05.001
引用本文: 申冠卿, 张原锋, 张敏. 黄河下游漫滩高含沙洪水滩槽界定及泥沙时空沉积特性[J]. 水科学进展, 2017, 28(5): 641-651. DOI: 10.14042/j.cnki.32.1309.2017.05.001
SHEN Guanqing, ZHANG Yuanfeng, ZHANG Min. Definition of channel and floodplain and spatio-temporal sedimentation characteristics for overbank hyperconcentrated flood in the lower Yellow River[J]. Advances in Water Science, 2017, 28(5): 641-651. DOI: 10.14042/j.cnki.32.1309.2017.05.001
Citation: SHEN Guanqing, ZHANG Yuanfeng, ZHANG Min. Definition of channel and floodplain and spatio-temporal sedimentation characteristics for overbank hyperconcentrated flood in the lower Yellow River[J]. Advances in Water Science, 2017, 28(5): 641-651. DOI: 10.14042/j.cnki.32.1309.2017.05.001

黄河下游漫滩高含沙洪水滩槽界定及泥沙时空沉积特性

Definition of channel and floodplain and spatio-temporal sedimentation characteristics for overbank hyperconcentrated flood in the lower Yellow River

  • 摘要: 黄河下游漫滩高含沙洪水河床调整剧烈,多数断面洪水后形成"相对窄深河槽",洪水前后河槽宽度发生明显变化。分别以观测断面洪水前后的河槽宽度为基准,计算漫滩高含沙洪水期泥沙时空沉积分布,结果表明,漫滩高含沙洪水与非漫滩高含沙洪水相比,能将主河槽内淤积泥沙量的59.3%搬运至嫩滩或滩地,减缓主河槽淤积。在分析研究基础上,建立了洪水后漫滩河段河槽相对缩窄率与洪水前期河槽宽度的量化关系,洪水后主槽宽度缩窄率为15.5%~44.0%;分析遴选了漫滩高含沙洪水滩地淤积量与主要水力因子间关联度及物理含义,给出了漫滩高含沙洪水滩地淤积量与相应水力因子间的响应函数;初步提出漫滩洪水河道塑槽淤滩的临界水沙配置指标,临界水沙系数取值为0.025~0.040。成果对高含沙洪水调控具有一定的指导意义。

     

    Abstract: A relatively narrow and deep channel can be formed, therefor visible change in channel width can be observed, at most of cross sections due to intensive channel adjustment during a hyperconcentrated flood in the lower Yellow River. The spatial and temporal distribution of sediment deposition was calculated for overbank hyperconcentrated floods by comparison of channel width after an overbank flood with that of non-overbank flood. Results shown that 59% of sediment that would be deposited in the main channel during non-overbank floods was removed by overbank hyperconcentrated floodsto the lower floodplain or floodplain. This indicated that overbank hyperconcentrated floods can reduce sediment deposition in the main channel comparing to non-overbank ones. Based on analysis of measured data, the relationship of channel contraction ratio, ranging from 15.5% to 44.0%, at overflow sections after floods to the channel width before floods was established. Correlation between sediment volume deposited on floodplain and the main hydraulic factors during overbank flooding period, as well as their physical meanings, was analyzed. Responding function of sediment volume deposited on floodplain to hydraulic factors was determined. A threshold index of flow and sediment load for floodplain deposition and main channel reforming during overbank hyperconcentrated floods was proposed, which was between 0.025 and 0.040. This research is significant to regulation of hyperconcentrated floods in the lower Yellow River.

     

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