Preliminary Assessment of Debris Flow Hazard in a Catchment under Extreme Condition

Conference paper (2015)
Copyright: © 2015 The Authors and IOS Press, Creative Commons CC-BY
DOI: https://doi.org/10.3233/978-1-61499-580-7-540
More Info
expand_more

Published Date

16-10-2015

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Abstract

Due to hilly terrain and frequent heavy rainstorms, debris flow is one of the most common and catastrophic hazards in Hong Kong. To mitigate the debris flow risk, prediction of the magnitude and consequence of debris flow is essential. The objective of this paper is to simulate debris flow hazards in a study area in Hong Kong. Assessment of the surface geology is firstly conducted to ascertain the source materials. The physical parameters of the loose materials such as size, location, and soil type are investigated. The volume, sediment concentration and resistance parameters for debris flows are subsequently evaluated and adopted as the input for the debris flow simulation. Numerical debris flow simulation is then conducted according to the established parameters. The maximum flow depth and maximum flow velocity are calculated by solving the continuity equation, the momentum equation and a friction slope equation. Based on the simulation results, a debris flow hazard map as a function of both the maximum flow depth and the maximum flow velocity is finally produced.