TY - JOUR
T1 - Numerical simulation of debris-flow behavior incorporating a dynamic method for estimating the entrainment
AU - Han, Zheng
AU - Chen, Guangqi
AU - Li, Yange
AU - Tang, Chuan
AU - Xu, Linrong
AU - He, Yi
AU - Huang, Xun
AU - Wang, Wei
N1 - Funding Information:
This study has received financial support from Kyushu University Interdisciplinary Programs in Education and Projects in Research Development . Also, this work was supported by JSPS KAKENHI Grant Number 22310113 and the Global Environment Research Found of Japan (S-8). These financial supports are gratefully acknowledged.
PY - 2015/5/4
Y1 - 2015/5/4
N2 - There is a pressing need to estimate debris-flow entrainment because several lines of studies have substantiated that the magnitude of a debris flow may grow manyfold due to sediment entrainment. In this paper, we present a two-dimensional numerical model of debris-flow behavior for estimating entrainment over complex topography. The model is governed by a numerical integration of the depth-average motion equations using shallow water approximation. The governing equations are numerically solved using the semi-Lagrangian method in an explicit finite difference grid. Compared to previous models, the presented model highlights the importance of entrainment, and incorporates a physically-based dynamic method to estimate the entrainment rate. The entrainment rate can be predicted using reasonable assumptions regarding the velocity profile of the debris flow and the rapidly changing pore pressure of the bed sediment. The stability of the presented model is first illustrated by a hypothesized dam-breaking problem; the effectiveness of the implemented model entrainment process is subsequently tested on the 2010 Yohutagawa debris-flow event in Japan. The test indicates that the presented method can be satisfactorily used to simulate debris-flow behavior and the entrainment process. A discussion regarding the advantages and limitations of the model concludes the paper.
AB - There is a pressing need to estimate debris-flow entrainment because several lines of studies have substantiated that the magnitude of a debris flow may grow manyfold due to sediment entrainment. In this paper, we present a two-dimensional numerical model of debris-flow behavior for estimating entrainment over complex topography. The model is governed by a numerical integration of the depth-average motion equations using shallow water approximation. The governing equations are numerically solved using the semi-Lagrangian method in an explicit finite difference grid. Compared to previous models, the presented model highlights the importance of entrainment, and incorporates a physically-based dynamic method to estimate the entrainment rate. The entrainment rate can be predicted using reasonable assumptions regarding the velocity profile of the debris flow and the rapidly changing pore pressure of the bed sediment. The stability of the presented model is first illustrated by a hypothesized dam-breaking problem; the effectiveness of the implemented model entrainment process is subsequently tested on the 2010 Yohutagawa debris-flow event in Japan. The test indicates that the presented method can be satisfactorily used to simulate debris-flow behavior and the entrainment process. A discussion regarding the advantages and limitations of the model concludes the paper.
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U2 - 10.1016/j.enggeo.2015.02.009
DO - 10.1016/j.enggeo.2015.02.009
M3 - Article
AN - SCOPUS:84924739364
SN - 0013-7952
VL - 190
SP - 52
EP - 64
JO - Engineering Geology
JF - Engineering Geology
ER -