Numerical Simulation of Debris Flow and the Characteristic of Rheological Parameters
Date Issued
2004
Date
2004
Author(s)
Chao, Chi-Hung
DOI
zh-TW
Abstract
Debris flow is a very serious disaster which always leads to huge damages in Taiwan. Fractural stratums and provide landslide caused by frequent earthquakes are the sources of debris. After typhoon or downpour, debris and water mixes to form debris flow. A lot of efforts have been done in recent years to understand the triggering criteria, flow routing and deposition of debris flow in order to reduce the impact and losses caused by debris flow. In this research, parameters needed and processes for a numerical simulation method for debris flow routing and deposition is formulated to provide reference for hazard zone mapping.
In previous studies of numerical simulation of debris flow, rheological parameters are ontroversial. Because of the difficulty of sampling and uncertainty of sediment concentration during debris flow, rheological parameters obtained from laboratory testing are significantly different from those observed in field. In this research, results from laboratory experiments and deposition evolution of debris-flow fans by Shieh and Tsai(1998,1999) are used. A debris flow model of the test constructed using Flo-2D, which is a dynamic flooding routing simulation model. Parametric studies and characteristics analyses are also performed. The rationality of parameters is discussed and the reasonable combinations of parameters are proposed for the case.
Case studies in this research consist of three phases. For the first phase, data of debris flow cases such as topography and rainfall information from Chenyulan river basin during 1996 typhoon Herb and Fong-Shan during 2001 typhoon Toraji are compiled and used to establish a debris flow influence factors database. For the second phase, numerical simulation was performed using Flo-2D, results were presented as area, maximum depositing depth, and volume deposited. Simulation results are compared with aerial photos and microgeomorphology study. Finally, suitable conditions for using this model and suggestions for future research are discussed.
Subjects
土石流
微地形
數值模擬
流變參數
Rheological Parameters
Debris Flow
Numerical Simulation
Microgeomorphology
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91521111-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):cf1a427eec7268818cb49c4352d5d534