The Experts below are selected from a list of 37989 Experts worldwide ranked by ideXlab platform
Yiguan Chi - One of the best experts on this subject based on the ideXlab platform.
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recent rainfall induced landslides and Debris Flow in northern taiwan
Geomorphology, 2006Co-Authors: Hongey Chen, Simon Dadson, Yiguan ChiAbstract:This paper discusses the factors initiating landslides and a large-scale Debris Flow in the Chonho area of Taipei County, northern Taiwan, which resulted from heavy rainfall during Typhoon Xangsane in November 2000. The morphology and triggering mechanism of the landslides and the Debris Flow were investigated using aerial photographs taken over the past 20 years, field measurement of channel cross-sections, laboratory assessment of slope material properties, and slope stability analysis. A large landslide that occurred in the source area was the initial source of material for the Debris Flow. The majority of the landslide Debris entered the main stream, where it mixed with water and became a Debris Flow. Eroding the sidewalls of the stream, the Debris Flow entrained additional material and traveled downstream into Chonho Village. Our findings indicate that the November 2000 landslides and the Debris Flow were strongly influenced by the physical properties of the underlying pyroclastic substrate and the pattern of bedrock discontinuities within the valleys.
F. K. Rengers - One of the best experts on this subject based on the ideXlab platform.
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Runoff-initiated post-fire Debris Flow Western Cascades, Oregon
Landslides, 2020Co-Authors: S. A. Wall, J. J. Roering, F. K. RengersAbstract:Wildfires dramatically alter the hydraulics and root reinforcement of soil on forested hillslopes, which can promote the generation of Debris Flows. In the Pacific Northwest, post-fire shallow landsliding has been well documented and studied, but the potential role of runoff-initiated Debris Flows is not well understood and only one previous to 2018 had been documented in the region. On 20 June 2018, approximately 1 year after the Milli fire burned 24,000 acres, a runoff-initiated Debris Flow occurred on the flanks of Black Crater in the Oregon Cascade Range. The Debris Flow was initiated via dispersed rilling on > 30-degree slopes near the crater rim and traveled > 1.5 km downslope. We measured exceptionally low soil infiltration rates at the study site, likely due to high burn severity during the Milli fire. Based on nearby 5-min rain gage data, we quantified rainfall rates for the storm event that triggered the Debris Flow. Our results show that peak 15-min rainfall rates were 25.4 mmh^−1, equaling or exceeding the measured infiltration rates at the study site, which had a geometric mean of ~ 24 mmh^−1. Field mapping shows that high burn severity resulted in the initiation of the Debris Flow and that convergent and steep topography promoted the development of a Debris Flow at this site. As wildfires increase in frequency and intensity across the western USA, the Pacific Northwest could become more susceptible to runoff-initiated Debris Flows. Therefore, characterization of the conditions that resulted in this Debris Flow is crucial for understanding how runoff-initiated Debris Flows may shape terrain and impact hazards in the Pacific Northwest.
Hongey Chen - One of the best experts on this subject based on the ideXlab platform.
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recent rainfall induced landslides and Debris Flow in northern taiwan
Geomorphology, 2006Co-Authors: Hongey Chen, Simon Dadson, Yiguan ChiAbstract:This paper discusses the factors initiating landslides and a large-scale Debris Flow in the Chonho area of Taipei County, northern Taiwan, which resulted from heavy rainfall during Typhoon Xangsane in November 2000. The morphology and triggering mechanism of the landslides and the Debris Flow were investigated using aerial photographs taken over the past 20 years, field measurement of channel cross-sections, laboratory assessment of slope material properties, and slope stability analysis. A large landslide that occurred in the source area was the initial source of material for the Debris Flow. The majority of the landslide Debris entered the main stream, where it mixed with water and became a Debris Flow. Eroding the sidewalls of the stream, the Debris Flow entrained additional material and traveled downstream into Chonho Village. Our findings indicate that the November 2000 landslides and the Debris Flow were strongly influenced by the physical properties of the underlying pyroclastic substrate and the pattern of bedrock discontinuities within the valleys.
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Mechanism of initiation of Debris Flow
Urban Disaster Mitigation: The Role of Engineering and Technology, 1995Co-Authors: Ruey-hwa Chen, Ming-lang Lin, Hongey ChenAbstract:Publisher Summary The initiation condition and failure mode of Debris Flow have been studied by many researchers, and several possible mechanisms of initiation of Debris Flow have been proposed. However, due to the difficulty of observing the initiation condition of Debris Flow in the field before and while it occurred, a model study was performed in this research. Material used in the model test was reconstituted with scaled-down particles and laws of similitude were taken into account while forming the model. The chapter also studies and stimulates mobilization of Debris Flows by inducing pore water pressure in samples during triaxial tests. The rate of the increase in pore water pressure was based on rainfall intensity and the coefficient of storage of the soil. The results show that the strength parameters of soils and the factors of safety obtained in slope stability analysis from conventional tests are higher than those obtained from this proposed method.
S. A. Wall - One of the best experts on this subject based on the ideXlab platform.
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Runoff-initiated post-fire Debris Flow Western Cascades, Oregon
Landslides, 2020Co-Authors: S. A. Wall, J. J. Roering, F. K. RengersAbstract:Wildfires dramatically alter the hydraulics and root reinforcement of soil on forested hillslopes, which can promote the generation of Debris Flows. In the Pacific Northwest, post-fire shallow landsliding has been well documented and studied, but the potential role of runoff-initiated Debris Flows is not well understood and only one previous to 2018 had been documented in the region. On 20 June 2018, approximately 1 year after the Milli fire burned 24,000 acres, a runoff-initiated Debris Flow occurred on the flanks of Black Crater in the Oregon Cascade Range. The Debris Flow was initiated via dispersed rilling on > 30-degree slopes near the crater rim and traveled > 1.5 km downslope. We measured exceptionally low soil infiltration rates at the study site, likely due to high burn severity during the Milli fire. Based on nearby 5-min rain gage data, we quantified rainfall rates for the storm event that triggered the Debris Flow. Our results show that peak 15-min rainfall rates were 25.4 mmh^−1, equaling or exceeding the measured infiltration rates at the study site, which had a geometric mean of ~ 24 mmh^−1. Field mapping shows that high burn severity resulted in the initiation of the Debris Flow and that convergent and steep topography promoted the development of a Debris Flow at this site. As wildfires increase in frequency and intensity across the western USA, the Pacific Northwest could become more susceptible to runoff-initiated Debris Flows. Therefore, characterization of the conditions that resulted in this Debris Flow is crucial for understanding how runoff-initiated Debris Flows may shape terrain and impact hazards in the Pacific Northwest.
Simon Dadson - One of the best experts on this subject based on the ideXlab platform.
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recent rainfall induced landslides and Debris Flow in northern taiwan
Geomorphology, 2006Co-Authors: Hongey Chen, Simon Dadson, Yiguan ChiAbstract:This paper discusses the factors initiating landslides and a large-scale Debris Flow in the Chonho area of Taipei County, northern Taiwan, which resulted from heavy rainfall during Typhoon Xangsane in November 2000. The morphology and triggering mechanism of the landslides and the Debris Flow were investigated using aerial photographs taken over the past 20 years, field measurement of channel cross-sections, laboratory assessment of slope material properties, and slope stability analysis. A large landslide that occurred in the source area was the initial source of material for the Debris Flow. The majority of the landslide Debris entered the main stream, where it mixed with water and became a Debris Flow. Eroding the sidewalls of the stream, the Debris Flow entrained additional material and traveled downstream into Chonho Village. Our findings indicate that the November 2000 landslides and the Debris Flow were strongly influenced by the physical properties of the underlying pyroclastic substrate and the pattern of bedrock discontinuities within the valleys.
