Hazard Assessment of Highways Affected by Debris Flows

2014 ◽  
Vol 501-504 ◽  
pp. 2455-2462 ◽  
Author(s):  
Qiang Zou
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Drainage Basins ◽  
Mountain Areas ◽  
Management Planning ◽  
Disaster Situation ◽  
Damage Process ◽  
Emergency Management Planning ◽  
Hazard Level ◽  
Debris Flow Hazard

Roads often run across various drainage basins in mountain areas which include complex geographic and geomorphic conditions. Highways in these areas have been frequently interrupted by debris flows. Without emergency management planning, such debris flows can lead to extensive life and property loss. Through analyzing the hazard effect modes and damage process along highways, we developed three key indexes, scale of debris flows, deposits on highways and river blockage, to describe the highway disasters quantitatively. According to actual investigation, we proposed new methods to determine the value of hazard indexes. Subsequently, we developed the assessment and mapping methods for highways safety by using hazard degree of debris flow. The hazard is graded into 4 grades as extreme low, low hazard, medium and high hazard level. Through applying this method, a case study was carried out on national highway G318 in Xiqu River basin. After analyzing debris flow hazard for the whole highway, the assessment results are consistent with the field surveyed data which indicate actual disaster situation. This hazard method can objectively evaluate the debris-flow hazard along highways, and is useful for highway reconstruction in mountainous areas suffering from active debris flows.

scholarly journals Debris Flow Assessment in the Gaizi-Bulunkou Section of Karakoram Highway

2021 ◽  
Vol 9 ◽  
Author(s):  
Ning Jiang ◽  
Fenghuan Su ◽  
Yong Li ◽  
Xiaojun Guo ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Regional Scale ◽  
Essential Information ◽  
Calculation Results ◽  
Karakoram Highway ◽  
Four Levels ◽  
Hazard Level ◽  
Debris Flow Hazard ◽  
Hazard Levels

Highways frequently run through the flow and accumulation areas of debris flow gullies and thus are susceptible to debris flow hazards. Assessing debris flows along highways can provide references for highway planners and debris flow control, emergency management. However, the existing assessment methods mostly neglect the essential information of the flow paths and spreading areas of debris flows at the regional scale. Taking the Gaizi Village-Bulunkou Township Section (hereinafter referred to as “the Gaizi-Bulunkou Section”) of the Karakoram highway as the study area, this research introduces a simple empirical model (the Flow-R model) and establishes a method for assessing the debris flow hazard level. The main processes include data collection, inventory of former events, calculating source areas and spreading probability, verification of the model, extraction of hazard assessment factors, and calculation of debris flow hazard levels. The results show that: 1) the accuracy, sensitivity, and positive predictive power of the Flow-R model in simulating the debris flow spreading probability of the study area were 81.87, 70.80 and 72.70%, respectively. The errors mainly occurred in the debris flow fans. 2) The calculation results make it possible to divide debris flow hazard levels into four levels. N5, N19, and N28 gullies had the highest hazard level during the study period. 3) In the Gaizi-Bulunkou Section of the Karakoram highway, during the study period, the highways with very high, high, medium, and low hazards were 4.33, 0.62, 1.41, and 1.68 km in length, respectively.

scholarly journals GIS-based Real-time Framework of Debris Flow Hazard Assessment for Expressways in Korea

2016 ◽  
Author(s):  
C. K. Chung ◽  
H. S. Kim ◽  
S. R. Kim ◽  
K. S. Kim
Keyword(s):  
Debris Flow ◽  
Real Time ◽  
Hazard Assessment ◽  
Debris Flows ◽  
Safety Management ◽  
Assessment Method ◽  
Monitoring Networks ◽  
Mountain Areas ◽  
Real Time System ◽  
Debris Flow Hazard

Abstract. Debris flows caused by heavy rainfall in mountain areas near expressways lead to severe social and economic loss and sometimes even result in casualties. However, in Korea, the design of road structures that resist these debris flow incidents are generally not carried out in a systematic way with proper concepts or procedures. Therefore, the development of a real-time system for debris flow hazard assessment is necessary to provide preliminary information for rapid decision making of evacuations or restoration measures, and to prevent second-hand disasters caused by debris flows. Recently, various map-based approaches have been proposed using multi-attribute criteria and assessment methods for debris flow susceptibilities. However, for the macro-zonation of debris flow hazards at a national scale, a simplified method such as the Korea Expressway Corporation debris flow hazard assessment method is appropriate and also applicable for systemization based on GIS and monitoring networks. In this study, a GIS-based real-time framework of debris flow hazards for expressway sections was newly proposed based on the KEC debris flow hazard assessment method. First, the KEC-based method was standardized in a systematic fashion using ESRI ArcGIS, enabling the objective and quantitative acquisition of various attribute datasets. Also, for a more precise assessment, the quantification of rainfall criteria was considered. Finally, a safety management system for debris flow hazards was developed based on a GIS platform, and was applied and verified on three expressway sections in Korea.

Modeling debris flow triggered by snow melting in the Barsemdara river valley, Tajikistan

2021 ◽  
Author(s):  
Viktoriia Kurovskaia ◽  
Sergey Chernomorets ◽  
Tatyana Vinogradova ◽  
Inna Krylenko
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Human Life ◽  
River Valley ◽  
Viscoplastic Fluid ◽  
Two Dimensional ◽  
Residential Areas ◽  
Subsequent Formation ◽  
Hazard Level ◽  
Output Information

<p>Debris flow is one of the most hazardous events that occur in all mountain regions.  Direct debris flow damage includes loss of human life, destruction of houses and facilities, damage to roads, rail lines and pipelines, vehicle accidents, and many other losses that are difficult to quantify. In July 2015, in the valley of the Barsemdara River (Gorno-Badakhshan Autonomous Region, Tajikistan), plenty of debris flows were observed. As a result, residential areas, social facilities, and infrastructure in Barsem village and neighboring settlements were destroyed and flooded. Besides, debris flow deposits blocked the Gunt River with the subsequent formation of a dammed lake with a maximum volume of 4.0 million m<sup>3</sup>. <br>The aim of this study was to obtain hydrographs of debris flow waves in the source and detailed zoning of the Barsemdara river valley. For the debris flow source, we applied transport-shift model. Equations of this model were developed by Yu.B. Vinogradov basing on Chemolgan experiments of artificial debris flows descending. Previously, the model characteristics were compared with the observational data of the Chemolgan experiments, and the results were found to be satisfactory [Vinogradova, Vinogradov, 2017]. Based on the equations, a computer program was created in the programming language Python. Besides, we improved the model by adding flow velocity calculations, and eventually it became possible to obtain hydrographs. To investigate quantitative characteristics of the debris flow in the river valley we implied a two-dimensional (2D) model called FLO-2D PRO. It is based on the numerical methods for solving the system of Saint-Venant equations. Besides, in this model, it is assumed that debris flows move like a Bingham fluid (viscoplastic fluid) [O'Brien et al., 1993]. The input information for modeling was digital elevation model (DEM) and previously obtained hydrographs. The output information included flow depth, velocity distribution and hazard level of the territory. The results of the study will be reported.</p><p>1.    Vinogradova T.A., Vinogradov A.Y. The Experimental Debris Flows in the Chemolgan River Basin // Natural Hazards. – 2017. – V. 88. – P. 189-198.<br>2.    O'Brien J. S., Julien P.Y., Fullerton W.T. Two-dimensional water flood and mudflow simulation //Journal of hydraulic engineering. – 1993. – V. 119, No 2. – P. 244-261.</p>

scholarly journals Applications of simulation technique on debris-flow hazard zone delineation: a case study in Hualien County, Taiwan

2010 ◽  
Vol 10 (3) ◽  
pp. 535-545 ◽  
Author(s):  
S. M. Hsu ◽  
L. B. Chiou ◽  
G. F. Lin ◽  
C. H. Chao ◽  
H. Y. Wen ◽  
...  
Keyword(s):  
Debris Flow ◽  
Yield Stress ◽  
Empirical Model ◽  
Water Conservation ◽  
Debris Flows ◽  
Sediment Concentration ◽  
Hazard Zone ◽  
Debris Flow Hazard ◽  
Debris Flow Disaster ◽  
Soil And Water

Abstract. Debris flows pose severe hazards to communities in mountainous areas, often resulting in the loss of life and property. Helping debris-flow-prone communities delineate potential hazard zones provides local authorities with useful information for developing emergency plans and disaster management policies. In 2003, the Soil and Water Conservation Bureau of Taiwan proposed an empirical model to delineate hazard zones for all creeks (1420 in total) with potential of debris flows and utilized the model to help establish a hazard prevention system. However, the model does not fully consider hydrologic and physiographical conditions for a given creek in simulation. The objective of this study is to propose new approaches that can improve hazard zone delineation accuracy and simulate hazard zones in response to different rainfall intensity. In this study, a two-dimensional commercial model FLO-2D, physically based and taking into account the momentum and energy conservation of flow, was used to simulate debris-flow inundated areas. Sensitivity analysis with the model was conducted to determine the main influence parameters which affect debris flow simulation. Results indicate that the roughness coefficient, yield stress and volumetric sediment concentration dominate the computed results. To improve accuracy of the model, the study examined the performance of the rainfall-runoff model of FLO-2D as compared with that of the HSPF (Hydrological Simulation Program Fortran) model, and then the proper values of the significant parameters were evaluated through the calibration process. Results reveal that the HSPF model has a better performance than the FLO-2D model at peak flow and flow recession period, and the volumetric sediment concentration and yield stress can be estimated by the channel slope. The validation of the model for simulating debris-flow hazard zones has been confirmed by a comparison of field evidence from historical debris-flow disaster data. The model can successfully replicate the influence zone of the debris-flow disaster event with an acceptable error and demonstrate a better result than the empirical model adopted by the Soil and Water Conservation Bureau of Taiwan.

scholarly journals 2D Runout Modelling of Hillslope Debris Flows, Based on Well-Documented Events in Switzerland

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 70 ◽  
Author(s):  
Florian Zimmermann ◽  
Brian W. McArdell ◽  
Christian Rickli ◽  
Christian Scheidl
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Mass Movement ◽  
Clay Content ◽  
Systematic Evaluation ◽  
Mountain Areas ◽  
Flow Processes ◽  
Friction Parameters ◽  
Cohesive Interaction ◽  
Hillslope Debris Flow

In mountain areas, mass movements, such as hillslope debris flows, pose a serious threat to people and infrastructure, although size and runout distances are often smaller than those of debris avalanches or in-channel-based processes like debris floods or debris flows. Hillslope debris-flow events can be regarded as a unique process that generally can be observed at steep slopes. The delimitation of endangered areas and the implementation of protective measures are therefore an important instrument within the framework of a risk analysis, especially in the densely populated area of the alpine region. Here, two-dimensional runout prediction methods are helpful tools in estimating possible travel lengths and affected areas. However, not many studies focus on 2D runout estimations specifically for hillslope debris-flow processes. Based on data from 19 well-documented hillslope debris-flow events in Switzerland, we performed a systematic evaluation of runout simulations conducted with the software Rapid Mass Movement Simulation: Debris Flow (RAMMS DF)—a program originally developed for runout estimation of debris flows and snow avalanches. RAMMS offers the possibility to use a conventional Voellmy-type shear stress approach to describe the flow resistance as well as to consider cohesive interaction as it occurs in the core of dense flows with low shear rates, like we also expect for hillslope debris-flow processes. The results of our study show a correlation between the back-calculated dry Coulomb friction parameters and the percentage of clay content of the mobilised soils. Considering cohesive interaction, the performance of all simulations was improved in terms of reducing the overestimation of the observed deposition areas. However, the results also indicate that the parameter which accounts for cohesive interaction can neither be related to soil physical properties nor to different saturation conditions.

Using Fuzzy Inference System to the Analysis of Debris Flow Hazard

2009 ◽  
Author(s):  
Pao H. Lin ◽  
K. H. Chen
Keyword(s):  
Debris Flow ◽  
Interface Design ◽  
Debris Flows ◽  
Evaluation System ◽  
Fuzzy Inference ◽  
Hazard Evaluation ◽  
Graphic User Interface ◽  
Design Environment ◽  
Inference System ◽  
Debris Flow Hazard

In this study 11 factors influential to the evolvement of debris flows are identified via literature review and a thorough comparison among previous studies. Aided by MATLAB software and the concept of property in Fuzzy logic theory, an evaluation system for debris flow hazard is developed. Also, the proposed inference system is facilitated with Graphic User Interface Design Environment, so that observers or researchers may easily become familiar with system operation and utilize the system’s estimation as references for hazard judgment. Validation results with simulated cases of three different degrees of hazard severity evidenced that the present evaluation system on debris flows was effective with debris flows of high, low, and median hazards, as well as acceptable feasibility. Further, based on data gathered from rivers subject to debris flow and several actual cases in Taiwan, this proposed system was proved to achieve acceptable precision on the hazard evaluation of debris flow.

scholarly journals GIS-based modelling of landslide and debris flow hazard in mountainous terrain of Agra Khola watershed, central Nepal

2006 ◽  
Vol 34 ◽  
pp. 117-128
Author(s):  
P. B. Thapa ◽  
T. Esaki ◽  
B. N. Upreti
Keyword(s):  
Debris Flow ◽  
Prediction Model ◽  
Debris Flows ◽  
Flow Distribution ◽  
Spatial Prediction ◽  
Distribution Map ◽  
Central Nepal ◽  
Landslides And Debris Flows ◽  
Debris Flow Hazard ◽  
Hazard Levels

A comprehensive GIS-based analytical approach was followed to derive a spatial database of landslides and debris flows in the Agra Khola watershed of central Nepal which suffered from the hydrological disaster of 1993. For this purpose, the landslides and debris flows occurring in that area between 1993 and 2006 were delineated. From the database, the influence of geological and geomorphic variables was quantified and a spatial prediction model for landslide and debris flow hazard was worked out. In this process, quantitative statistical analysis (bivariate, multivariate) as applied to predict elements or observations between stable and unstable zones. The predicted results were classified into various hazard levels m a hazard map and were validated by comparing it with the landslide and debris flow distribution map of the Agra Khola watershed. Also the GIS-based hazard prediction model has objectivity in the procedure and reproducibility of the results in the mountainous terrains.

scholarly journals Debris-flow hazard assessment at regional scale by combining susceptibility mapping and radar rainfall

2014 ◽  
Vol 2 (10) ◽  
pp. 6295-6338
Author(s):  
M. Berenguer ◽  
D. Sempere-Torres ◽  
M. Hürlimann
Keyword(s):  
Debris Flow ◽  
Hazard Assessment ◽  
Regional Scale ◽  
Early Warning Systems ◽  
Warning Systems ◽  
Radar Rainfall ◽  
Eastern Pyrenees ◽  
Hazard Level ◽  
Rainfall Map ◽  
Debris Flow Hazard

Abstract. This work presents a technique for debris flow (DF) hazard assessment able to be used in the framework of DF early warning systems at regional scale. The developed system is applied at subbasin scale and is based on the concepts of fuzzy logic to combine two ingredients: (i) DF subbasin susceptibility assessment based on geomorphological variables, and (ii) the magnitude of the rainfall situation as depicted from radar rainfall estimates. The output of the developed technique is a three-class hazard level ("low", "moderate" and "high") in each subbasin when a new radar rainfall map is available. The developed technique has been applied in a domain in the Eastern Pyrenees (Spain) from May to October 2010. The estimated hazard level stayed "low" during the entire period in 20% of the subbasins, while, in the most susceptible subbasins, the hazard level was at least moderate for up to10 days. Quantitative evaluation of the estimated hazard level was possible in a subbasin where debris flows were monitored during the analysis period. The technique was able to identify the 3 events observed in the catchment (1 debris flow and 2 hyperconcentrated flow events) and produced no false alarm.

scholarly journals Debris-Flow Hazard Assessments: A Practitioner's View

2021 ◽  
Author(s):  
Matthias Jakob
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Three Dimensional ◽  
Extreme Value Statistics ◽  
Major Life ◽  
Two Factors ◽  
Hazard Assessments ◽  
Cost Efficient ◽  
Multi Phase ◽  
Debris Flow Hazard

ABSTRACT Substantial advances have been achieved in various aspects of debris-flow hazard assessments over the past decade. These advances include sophisticated ways to date previous events, two- and three-dimensional runout models including multi-phase flows and debris entrainment options, and applications of extreme value statistics to assemble frequency–magnitude analyses. Pertinent questions have remained the same: How often, how big, how fast, how deep, how intense, and how far? Similarly, although major life loss attributable to debris flows can often, but not always, be avoided in developed nations, debris flows remain one of the principal geophysical killers in mountainous terrains. Substantial differences in debris-flow hazard persist between nations. Some rely on a design magnitude associated with a specific return period; others use relationships between intensity and frequency; and some allow for, but do not mandate, in-depth quantitative risk assessments. Differences exist in the management of debris-flow risks, from highly sophisticated and nation-wide applied protocols to retroaction in which catastrophic debris flows occur before they are considered for mitigation. Two factors conspire to challenge future generations of debris-flow researchers, practitioners, and decision makers: Population growth and climate change, which are increasingly manifested by augmenting hydroclimatic extremes. While researchers will undoubtedly finesse future remote sensing, dating, and runout techniques and models, practitioners will need to focus on translating those advances into practical cost-efficient tools and integrating those tools into long-term debris-flow risk management.

scholarly journals Debris flow hazard modelling on medium scale: Valtellina di Tirano, Italy

2010 ◽  
Vol 10 (11) ◽  
pp. 2379-2390 ◽  
Author(s):  
J. Blahut ◽  
P. Horton ◽  
S. Sterlacchini ◽  
M. Jaboyedoff
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Flow Direction ◽  
Hazard Analysis ◽  
Regional Scale ◽  
Aerial Photographs ◽  
Hazard Zonation ◽  
Conditioning Factors ◽  
Medium Scale ◽  
Debris Flow Hazard

Abstract. Debris flow hazard modelling at medium (regional) scale has been subject of various studies in recent years. In this study, hazard zonation was carried out, incorporating information about debris flow initiation probability (spatial and temporal), and the delimitation of the potential runout areas. Debris flow hazard zonation was carried out in the area of the Consortium of Mountain Municipalities of Valtellina di Tirano (Central Alps, Italy). The complexity of the phenomenon, the scale of the study, the variability of local conditioning factors, and the lacking data limited the use of process-based models for the runout zone delimitation. Firstly, a map of hazard initiation probabilities was prepared for the study area, based on the available susceptibility zoning information, and the analysis of two sets of aerial photographs for the temporal probability estimation. Afterwards, the hazard initiation map was used as one of the inputs for an empirical GIS-based model (Flow-R), developed at the University of Lausanne (Switzerland). An estimation of the debris flow magnitude was neglected as the main aim of the analysis was to prepare a debris flow hazard map at medium scale. A digital elevation model, with a 10 m resolution, was used together with landuse, geology and debris flow hazard initiation maps as inputs of the Flow-R model to restrict potential areas within each hazard initiation probability class to locations where debris flows are most likely to initiate. Afterwards, runout areas were calculated using multiple flow direction and energy based algorithms. Maximum probable runout zones were calibrated using documented past events and aerial photographs. Finally, two debris flow hazard maps were prepared. The first simply delimits five hazard zones, while the second incorporates the information about debris flow spreading direction probabilities, showing areas more likely to be affected by future debris flows. Limitations of the modelling arise mainly from the models applied and analysis scale, which are neglecting local controlling factors of debris flow hazard. The presented approach of debris flow hazard analysis, associating automatic detection of the source areas and a simple assessment of the debris flow spreading, provided results for consequent hazard and risk studies. However, for the validation and transferability of the parameters and results to other study areas, more testing is needed.

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