Multiple Time Scales of Fluvial Processes with Bed Load Sediment and Implications for Mathematical Modeling
Multiple Time Scales of Fluvial Processes with Bed Load Sediment and Implications for Mathematical Modeling
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DOI：
10.1061/(asce)hy.1943-7900.0000296
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发表时间：
2011-03
影响因子：
2.4
通讯作者：
Z. Cao;P. Hu;G. Pender
中科院分区：
文献类型：
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作者：
Z. Cao;P. Hu;G. Pender
河床推移质输运通常被认为是假定一个容量制度完全由当地的流动条件，但其在自然发生的非恒定流的适用性仍有待理论证明。此外，河流数学模型往往是解耦的，基于简化的守恒方程，在一定程度上忽略了河床变形的反馈影响。到目前为止，是否脱钩可能有相当大的影响，推移质输运的河流过程仍然知之甚少。本文对这两个问题进行了理论研究。对推移质输沙过程的多时间尺度进行了评价，以检验推移质输沙能力和解耦模型的适用性。数值案例研究涉及积极推移质输运高度不稳定流补充的时间尺度的分析。结果表明，由于泥沙运动的影响，推移质输沙能够充分迅速地适应与当地水流相一致的能力。
Fluvial bed load transport is often considered to assume a capacity regime exclusively determined by local flow conditions, but its applicability in naturally occurring unsteady flows remains to be theoretically justified. In addition, mathematical river models are often decoupled, being based on simplified conservation equations and ignoring the feedback impacts of bed deformation to a certain extent. So far whether the decoupling could have considerable impacts on the fluvial processes with bed load transport remains poorly understood. This paper presents a theoretical investigation of both issues. The multiple time scales of fluvial processes with bed load sediment are evaluated to examine the applicability of bed load transport capacity and decoupled models. Numerical case studies involving active bed load transport by highly unsteady flows complement the analysis of the time scales. It is found that bed load transport can sufficiently rapidly adapt to capacity in line with local flow because sediment...