Inverse estimation of distributed roughness coefficients in vegetated flooded rivers
Inverse estimation of distributed roughness coefficients in vegetated flooded rivers
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DOI：
10.1080/00221686.2014.932854
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发表时间：
2014-11
影响因子：
2.3
通讯作者：
Keisuke Yoshida;S. Maeno
中科院分区：
文献类型：
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作者：
Keisuke Yoshida;S. Maeno
摘要本文介绍了天然河流中植被引起的河床糙率的资料同化方法。发展了一个用于变分资料同化的伴随浅水模式。最佳值的分布床糙率系数确定使用准牛顿方法与流量和伴随变量。应用数据同化技术反演了2011年日本朝日河下游洪水期间的分布系数。在实际应用中，同化数据包括沿沿着定期测量的水位。结果表明，分布在目标分区的每个系数的大小是合理的一致，在相应的分区建立的植被物种，考虑到与流动阻力的植被特征值。
ABSTRACT This paper describes data assimilation for estimating bed roughness factor due to vegetation in natural rivers. An adjoint shallow-water model was developed for variational data assimilation. Optimal values for distributed bed roughness coefficients were determined using a quasi-Newtonian method with flow and adjoint variables. The data assimilation technique was applied to inverse estimation of the distributed coefficients in the lower reaches of the Asahi River in Japan during flooding in 2011. For practical use, the assimilated data comprised water levels measured along the river at regular time intervals. Results show that the magnitude of each coefficient distributed over targeted subregions was reasonably consistent with the vegetation species established in the corresponding subregion, considering characteristic values of vegetation related to the flow resistance.