A new approach for analyzing the velocity distribution of debris flows at typical cross-sections

Zheng Han, Guangqi Chen, Yange Li, Linrong Xu, Lu Zheng, Yingbing Zhang

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The asymmetrical distribution of debris-flow velocity in a cross-section has long been observed and is currently regarded as one of the most essential issues in debrisflow research. Due to a lack of quantitative models for the velocity distributions of debris flows, most studies consider only the mean velocity. However, to optimize countermeasure structures, to estimate the erosion rate, or to evaluate the constitutive equations for shear behavior, it is beneficial to know the velocity profile in a cross-section. In this paper, a generalized model of typical channel geometries (e.g., rectangular, trapezoid, or V-shape) is proposed. A description of the velocity distribution that optimizes the Manning–Strickler velocity equation for transverse distribution and Egashira’s velocity equation for vertical distribution is presented; thus, the debris-flow velocity at any point in the cross-section can be calculated and the distribution profile therefore obtained. A well-documented debrisflow reference case and the Jiasikou debris flow in the high-seismic-intensity zone of the Wenchuan earthquake are selected as case studies to demonstrate the model. Analyses of both cases confirm the asymmetrical distribution of debris-flow velocity in cross-section, as originally expected. This shows that the velocity at the top surface in the middle of the channel is much larger than that at each sidewall and than the mean value calculated by former equations. The obtained velocity distribution profile is a better approximation of the observed field profiles.

Original languageEnglish
Pages (from-to)2053-2070
Number of pages18
JournalNatural Hazards
Volume74
Issue number3
DOIs
Publication statusPublished - Nov 1 2014

Fingerprint

debris flow
cross section
flow velocity
constitutive equation
distribution
velocity profile
erosion rate
vertical distribution
geometry
earthquake

All Science Journal Classification (ASJC) codes

  • Water Science and Technology
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)

Cite this

A new approach for analyzing the velocity distribution of debris flows at typical cross-sections. / Han, Zheng; Chen, Guangqi; Li, Yange; Xu, Linrong; Zheng, Lu; Zhang, Yingbing.

In: Natural Hazards, Vol. 74, No. 3, 01.11.2014, p. 2053-2070.

Research output: Contribution to journalArticle

Han, Zheng ; Chen, Guangqi ; Li, Yange ; Xu, Linrong ; Zheng, Lu ; Zhang, Yingbing. / A new approach for analyzing the velocity distribution of debris flows at typical cross-sections. In: Natural Hazards. 2014 ; Vol. 74, No. 3. pp. 2053-2070.
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