Kuskonook Creek, an example of a debris flow analysis

Debris flow materials behave as a fluid, hence its analysis requires rheological parameters such as yield stress and viscosity. Yield stress is associated to the start and the end of the mass movement downhill in the sense that it denotes the yield transition from the creep to the flow regime, i.e., passage from solid to fluid state. This paper presents an experimental study of the yield stress of a colluvium from Rio de Janeiro, through its determination in a modified set-up of the slump test and in a rotational parallel plate rheometer. Tests were performed in five different water contents above its liquidity limit, providing a fairly good relationship between yield stress and water content. While slump test provides yield stress related to the beginning of the movement (acceleration), rheometer results are related to flow's outset and stoppage. As a result, the percentual differences between yield stresses associated with acceleration and deceleration were less than 5% in all testes, which is related to the low hysteresis effect in the flow curves obtained in the rotational rheometer. Comparing the two methodologies, it is proposed a correction from rheometer to slump test results. Results obtained are compared with data presented in other studies involving soil's yield stress, showing a good acceptance of the slump test results as a cheap alternative to rheometers.

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A TWO LAYER FLOW ANALYSIS OF DEBRIS FLOW CONSIDERING VERTICAL DISTRIBUTION OF VELOCITY AND CONCENTRATION

PROCEEDINGS OF HYDRAULIC ENGINEERING ◽

10.2208/prohe.48.889 ◽

2004 ◽

Vol 48 ◽

pp. 889-894

Author(s):

Jun-ichiro TAKAHAMA ◽

Yuichiro FUJITA ◽

Kousuke YOSHINO

Keyword(s):

Debris Flow ◽

Vertical Distribution ◽

Flow Analysis ◽

Layer Flow

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EDDA 2.0: integrated simulation of debris flow initiation and dynamics, considering two initiation mechanisms

10.5194/gmd-2017-204 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ping Shen ◽

Limin Zhang ◽

Hongxin Chen ◽

Ruilin Fan

Keyword(s):

Risk Assessment ◽

Debris Flow ◽

Debris Flows ◽

Flow Analysis ◽

Model Performance ◽

Integrated Model ◽

Field Application ◽

Surface Erosion ◽

Integrated Simulation ◽

Debris Flow Initiation

Abstract. Climate change results in more frequent rainstorms and more rain-induced debris flows in mountainous areas. The prediction of likely hazard zones is important for debris flow risk assessment and management. Existing numerical methods for debris flow analysis often require the input of hydrographs at prescribed initiation locations, ignoring the initiation process and leading to large uncertainties in debris flow initiation locations, times and volumes when applied to regional debris flow analysis. The evolution of the flowing mixture in time and space is hardly addressed either. This paper presents a new integrated numerical model, EDDA 2.0, to simulate the whole process of debris-flow initiation, motion, entrainment, deposition and property changes. Two physical initiation mechanisms are modeled: transformation from slope failures and surface erosion. Three numerical tests and field application to a catastrophic debris flow event are conducted to verify the model components and evaluate the model performance. The results indicate that the integrated model is capable of simulating the initiation and subsequent flowing process of rain-induced debris flows, as well as the physical evolution of the flowing mixture. The integrated model provides a powerful tool for analyzing multi-hazard processes, hazard interactions and regional debris-flow risk assessment in the future.

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Debris Flow Analysis of Landslide Area in Inje Using GIS

Journal of the Korean Society of Surveying Geodesy Photogrammetry and Cartography ◽

10.7848/ksgpc.2011.29.1.47 ◽

2011 ◽

Vol 29 (1) ◽

pp. 47-53 ◽

Cited By ~ 3

Author(s):

Gi-Hong Kim ◽

Chan-Young Yune ◽

Hwan-Gil Lee ◽

Jae-Seon Hwang

Keyword(s):

Debris Flow ◽

Flow Analysis ◽

Landslide Area

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Debris Flow Generation Based on Critical Discharge: A Case Study of Xiongmao Catchment, Southwestern China

10.20944/preprints202001.0012.v1 ◽

2020 ◽

Author(s):

Lingfeng Gong ◽

Chuan Tang ◽

Jiang Xiong ◽

Ning Li

Keyword(s):

Debris Flow ◽

Flow Analysis ◽

Solid Particles ◽

Rainfall Pattern ◽

K Value ◽

Rainfall Frequency ◽

Critical Discharge ◽

Key Factor ◽

Discharge Parameters ◽

Rainfall Patterns

A debris flows generation related to a poorly sorted mixture of soil, catchment topography and rainfall characteristic. Runoff of some depth on valley resulting from intensive rainfall can incur the sediments movement of beds or adjacent banks. The fluid flow in channel affected by rainfall parameters combinations, such as duration, intensity, cumulative rainfall, etc., is the key factor for debris movement. In this paper, the rainfall characteristics and occurrence conditions of debris flow in Xiongmao gully on July, 26th, 2016, have been explored, combined with field survey and indoor simulation experiment on the collected critical discharge parameters of debris movement. Further, debris distribution and the critical discharge characteristics have been analysed, by means of investigation on the catchment topography and occurrence cause of the debris flow, analysis of the critical discharge parameters on which the channel debris began to move, and K value clustering analysis method to characterize the rainfall pattern of the studied area, the discharge calculation of debris flow occurring in different rainfall patterns. The results have shown that, for the debris flow occurrence in Xiongmao gully, the debris initiation on the middle reaches of the gully provide the majority of solid particles for the disaster on July, 26th, 2016, and the upstream confluent provided catchment. Based on the relationship obtained from laboratory test, in which the calculated critical discharge was 43.8m3/s, less than the peak discharge (Qc =66.7m3/s), calculated by morphological method. In addition, it has been indicated that the dominated rainfall patterns of the studied area are first-quartile and second-quartile, that is, the rainfall is primarily at earlier or middle to preliminary stage of this time rainfall event. The critical discharge for the occurrence of debris flow on July, 26th was achieved 20a rainfall frequency, the larger runoff volume generated on shorten heavily rainfall. Based on individuality characteristics, such as distributed hydrological analysis, critical discharge and rainfall pattern of debris flow, the forewarning could be more efficient.

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EDDA 2.0: integrated simulation of debris flow initiation and dynamics considering two initiation mechanisms

Geoscientific Model Development ◽

10.5194/gmd-11-2841-2018 ◽

2018 ◽

Vol 11 (7) ◽

pp. 2841-2856 ◽

Cited By ~ 10

Author(s):

Ping Shen ◽

Limin Zhang ◽

Hongxin Chen ◽

Ruilin Fan

Keyword(s):

Risk Assessment ◽

Debris Flow ◽

Debris Flows ◽

Flow Analysis ◽

Model Performance ◽

Integrated Model ◽

Field Application ◽

Surface Erosion ◽

Integrated Simulation ◽

Debris Flow Initiation

Abstract. Climate change is resulting in more frequent rainstorms and more rain-induced debris flows in mountainous areas. The prediction of likely hazard zones is important for debris flow risk assessment and management. Existing numerical methods for debris flow analysis often require the input of hydrographs at prescribed initiation locations, ignoring the initiation process and leading to large uncertainties in debris flow initiation locations, times, and volumes when applied to regional debris flow analysis. The evolution of the flowing mixture in time and space is also barely addressed. This paper presents a new integrated numerical model, EDDA 2.0, to simulate the whole process of debris flow initiation, motion, entrainment, deposition, and property changes. Two physical initiation mechanisms are modelled: transformation from slope failures and surface erosion. Three numerical tests and field application to a catastrophic debris flow event are conducted to verify the model components and evaluate the model performance. The results indicate that the integrated model is capable of simulating the initiation and subsequent flowing process of rain-induced debris flows, as well as the physical evolution of the flowing mixture. The integrated model provides a powerful tool for analysing multi-hazard processes, hazard interactions, and regional debris flow risk assessment in the future.

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