Modelling the effect of time‐dependent river dune evolution on bed roughness and stage
Modelling the effect of time‐dependent river dune evolution on bed roughness and stage
复制标题
模拟随时间变化的河流沙丘演化对河床粗糙度和阶段的影响
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
R. Schielen
中科院分区：
文献类型：
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作者：
A. Paarlberg;C. Dohmen‐Janssen;S. Hulscher;P. Termes;R. Schielen
本文提出了一种方法，将随时间变化的沙丘演变中应用的水力模型中的床糙率系数的确定。沙丘粗糙度是通过使用Paarlberg等人的基于过程的沙丘演变模型计算的。（2009）和货车Rijn（1984）的经验沙丘粗糙度预测器。该方法通过将其应用于1-D水力模型SOBEK中的简单几何形状的河流来说明，用于两种不同的洪水波形状。计算的沙丘高度清楚地显示出依赖于流量随时间的变化率：沙丘增长到更大的高度，洪水波的变化率较小。床粗糙度系数计算使用新的方法可以高达10%以上的粗糙度系数的基础上校准，在低流量的最大差异。由于这种较大的河床粗糙度，在低流量时计算的水深可大15%。新的方法有助于减少不确定性的床糙率系数的流量模型，特别是河流系统流量随时间变化很大。版权所有© 2010约翰威利父子有限公司.
This paper presents an approach to incorporate time‐dependent dune evolution in the determination of bed roughness coefficients applied in hydraulic models. Dune roughness is calculated by using the process‐based dune evolution model of Paarlberg et al. ( 2009 ) and the empirical dune roughness predictor of Van Rijn ( 1984 ). The approach is illustrated by applying it to a river of simple geometry in the 1‐D hydraulic model SOBEK for two different flood wave shapes. Calculated dune heights clearly show a dependency on rate of change in discharge with time: dunes grow to larger heights for a flood wave with a smaller rate of change. Bed roughness coefficients computed using the new approach can be up to 10% higher than roughness coefficients based on calibration, with the largest differences at low flows. As a result of this larger bed roughness, computed water depths can be up to 15% larger at low flow. The new approach helps to reduce uncertainties in bed roughness coefficients of flow models, especially for river systems with strong variations in discharge with time. Copyright © 2010 John Wiley & Sons, Ltd.