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.

Tree rings and debris flows: Recent developments, future directions

2010 ◽  
Vol 34 (5) ◽  
pp. 625-645 ◽  
Author(s):  
Michelle Bollschweiler ◽  
Markus Stoffel
Keyword(s):  
Debris Flow ◽  
Tree Rings ◽  
Debris Flows ◽  
Mass Movement ◽  
Wide Field ◽  
Mountain Areas ◽  
Additional Information ◽  
Recent Developments ◽  
Spatial Positioning ◽  
The Impact

The sudden and unpredictable occurrence of debris flows poses major problems in many mountain areas in the world. For a realistic hazard assessment, knowledge of past events is of crucial importance. As archival data is generally fragmentary, additional information sources are needed for an appraisal of past and contemporary events as well as for the prediction of potential future events. Tree rings represent a very valuable natural archive on past debris-flow occurrence as they may record the impact of events in their tree-ring series. In the past few years, dendrogeomorphology has evolved from a pure dating tool to a broad range of applications. Besides the reconstruction of frequencies, tree rings allow — if coupled with spatial positioning methods — the determination of spread and reach of past events. Similarly, the wide field of applications includes the identification of magnitudes and triggers of debris-flow events. Besides demonstrating recent developments in the use of tree rings for debris-flow research, this contribution also provides a short overview on the application of tree rings for other mass-movement processes and highlights further possibilities of the method. Established techniques can be applied to related processes such as debris floods, flash floods or lahars. Data obtained can also be used to calibrate modeling approaches. The impact of past and future climatic changes on debris-flow occurrence is furthermore an important aspect where tree rings can be of help.

BARSEM DEBRIS FLOW DISASTER IN THE PAMIRS IN 2015 AND ITS ANALOGUES IN THE CENTRAL CAUCASUS

2019 ◽  
Vol XIII (1/2019) ◽  
pp. 26-36
Author(s):  
MIKHAIL DOKUKIN ◽  
SERGEY CHERNOMORETS ◽  
ELENA SAVERNYUK ◽  
EDUARD ZAPOROZHCHENKO ◽  
RUSLAN BOBOV ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Large Scale ◽  
River Valley ◽  
Mountain Areas ◽  
Form Analysis ◽  
Flow Processes ◽  
Central Caucasus ◽  
Left Tributary ◽  
Debris Flow Disaster

we characterize specific features of formation and consequences of the debris flow disaster occurred on the Barsemdara River in the Gunt River valley (Barsem village, Gorno-Badakhshan Autonomous Region, Tajikistan) on July 16–24, 2015. The paper presents the data on debris flow events with similar formation mechanism that took place in the following river valleys: Adyr-Su in 1940, 1983 and 2011, Tyutyun-Su in 1953, Khaznidon in 1975 et al. A common feature of the considered debris flows is the confinedness of debris flow site to special glacial accumulation forms — moraine pedestals containing a large amount of buried ice. Due to large-scale and long-term debris flow processes moraine pedestals take the shape of gullies. The largest example of considered landform is the debris flow gully (1 km-length) situated in the upper reaches of the Tyutyun-Su River in the Cherek Balkarskiy River basin (Central Caucasus). Similar debris flow processes were also observed in other mountain areas (Zaas River valley (Switzerland) in 1987, valley of the Ishkoman River left tributary (Pakistan) in 2018). Volumes of debris flow material carried out from moraine pedestals reach 1–5 million m3. In 2015 part of the Barsem village territory became covered with debris flow deposits and a dam was formed on the Gunt River above which is the Barsemkul dammed lake now. Places of possible debris flows such as Barsem disasters can be determined on the basis of glacial accumulation form analysis and identification of moraine pedestals in which the debris flow incisions are not yet developed.

Evidence for catastrophic volcanic debris flows in Pemberton Valley, British Columbia

2006 ◽  
Vol 43 (6) ◽  
pp. 679-689 ◽  
Author(s):  
K A Simpson ◽  
M Stasiuk ◽  
K Shimamura ◽  
J J Clague ◽  
P Friele
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Debris Flows ◽  
Clay Content ◽  
Volcanic Complex ◽  
Large Magnitude ◽  
Volcanic Material ◽  
Inundation Maps ◽  
The Matrix ◽  
Volcanic Debris

The Mount Meager volcanic complex in southern British Columbia is snow and ice covered and has steep glaciated and unstable slopes of hydrothermally altered volcanic deposits. Three large-volume (>108 m3) volcanic debris flow deposits derived from the Mount Meager volcanic complex have been identified. The volcanic debris flows travelled at least 30 km downstream from the volcanic complex and inundated now populated areas of Pemberton Valley. Clay content and mineralogy of the deposits indicate that the volcanic debris flows were clay-rich (5%–7% clay in the matrix) and derived from hydrothermally altered volcanic material. The youngest volcanic debris flow deposit is interpreted to be associated with the last known volcanic eruption, ~2360 calendar (cal) years BP. The other two debris flows may not have been directly associated with eruptions. Volcanic debris flow hazard inundation maps have been produced using the Geographic Information System (GIS)-based modelling program, LAHARZ. The maps provide estimates of the areas that would be inundated by future moderate to large-magnitude events. Given the available data, the probability of a volcanic debris flow reaching populated areas in Pemberton Valley is ~1 in 2400 years. Additional mapping in the source regions is necessary to determine if sufficient material remains on the volcanic edifice to generate future large-magnitude, clay-rich volcanic debris flows.

scholarly journals Debris flows in the central sector of the northern slopes of the Main Caucasus Ridge: peculiarities of the current situation

2016 ◽  
Vol 50 (1) ◽  
pp. 143-154 ◽  
Author(s):  
E. V. Zaporozhchenko
Keyword(s):  
Debris Flow ◽  
21St Century ◽  
Debris Flows ◽  
Meteorological Data ◽  
Current Situation ◽  
Modern Trend ◽  
Mountainous Areas ◽  
Single Model ◽  
Rock Falls ◽  
Flow Processes

This paper provides examples of real events of debris flows in the 21st century. The analysis of the debris flows reveals that there is a variety of manifestation of debris flow processes and triggering factors. It also demonstrates the lack of prospects for the modern trend of creating a single model for forecasting the occurrence, development, impacts and parameters of debris flows that would be equally suitable for other phenomena of gravitational nature such as avalanches, landslides or rock falls. Moreover, it shows that the monitoring is unrepresentative, which is unacceptable, and demonstrates the often lack of hydro-meteorological data on mountainous areas.

Debris flow magnitude estimation based on infrasound and seismic signals

2020 ◽  
Author(s):  
Andreas Schimmel ◽  
Matteo Cesca ◽  
Pierpaolo Macconi ◽  
Velio Coviello ◽  
Francesco Comiti
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Warning System ◽  
Early Warning Systems ◽  
Peak Discharge ◽  
Detection Methods ◽  
Mountain Areas ◽  
Detection And Identification ◽  
European Mountain ◽  
The Alps

<p>With the rapid socio-economic development of European mountain areas, the automatic detection and identification of mass movements like landslides, debris flows, and avalanches become more and more important to mitigate related risks by means of early warning systems. Past studies showed that such processes induce characteristic seismic and acoustic signals, the latter mostly in the infrasonic spectrum which can thus be used for event detection. Several investigations have already addressed signal processing and detection methods based on seismic or infrasound sensors. However, for developing an efficient warning system, not only the detection of events is important but also the identification of the event type (e.g. debris flow vs debris flood) and the estimation of its magnitude. So far, no method for such objectives has been developed which is based on the combination of both seismic and infrasonic signals.</p><p>This work presents a first approach to identify debris flows and debris floods magnitude based on the integration of infrasound and seismic data. First analysis shows that, for peak discharge, the use of infrasound amplitudes with a power curve fitting offers a good approach for finding an initial relationship between the recorded signals and this event parameter. For an estimation of the total volume, the discharge calculated with the relationship for peak discharge is integrated over the entire detection time of an event. Calculation of the peak discharge based on infrasound data offers a good approximation, but, for the calculation of the total volume, this method shows still a wide variance.</p><p>The method will be applied to seismic and infrasound data collected on three different test sites in the Alps: Gadria (South Tyrol, Italy), Lattenbach (Tyrol, Austria), and Cancia (Belluno, Italy).</p>

scholarly journals Acoustic module of the Acquabona (Italy) debris flow monitoring system

2005 ◽  
Vol 5 (2) ◽  
pp. 211-215 ◽  
Author(s):  
A. Galgaro ◽  
P. R. Tecca ◽  
R. Genevois ◽  
A. M. Deganutti
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Regression Line ◽  
Front Velocity ◽  
Peak Discharge ◽  
Physical Parameters ◽  
Flow Depth ◽  
Ground Vibrations ◽  
Mountain Areas ◽  
Flow Monitoring

Abstract. Monitoring of debris flows aimed to the assessment of their physical parameters is very important both for theoretical and practical purposes. Peak discharge and total volume of debris flows are crucial for designing effective countermeasures in many populated mountain areas where losses of lives and property damage could be avoided. This study quantifies the relationship between flow depth, acoustic amplitude of debris flow induced ground vibrations and front velocity in the experimental catchment of Acquabona, Eastern Dolomites, Italy. The analysis of data brought about the results described in the following. Debris flow depth and amplitude of the flow-induced ground vibrations show a good positive correlation. Estimation of both mean front velocity and peak discharge can be simply obtained monitoring the ground vibrations, through geophones installed close to the flow channel; the total volume of debris flow can be so directly estimated from the integral of the ground vibrations using a regression line. The application of acoustic technique to debris flow monitoring seems to be of the outmost relevance in risk reduction policies and in the correct management of the territory. Moreover this estimation is possible in other catchments producing debris flows of similar characteristics by means of their acoustic characterisation through quick and simple field tests (Standard Penetration Tests and seismic refraction surveys).

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 Modelling Using RAMMS Model in the Alpine Environment With Focus on the Model Parameters and Main Characteristics

2021 ◽  
Vol 8 ◽  
Author(s):  
Matjaž Mikoš ◽  
Nejc Bezak
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Mass Movement ◽  
Friction Model ◽  
Economic Damage ◽  
Model Parameters ◽  
Comprehensive Overview ◽  
Alpine Environment ◽  
Flow Modelling ◽  
Parameter Ranges

Debris flows are among the natural hazards that can occur in mountainous areas and endanger people’s lives and cause large economic damage. Debris flow modelling is needed in multiple applications such as design of protection measures or preparation of debris flow risk maps. Many models are available that can be used for debris flow modelling. The Rapid Mass Movement Simulation (RAMMS) model with its debris flow module, (i.e. RAMMS-DF) is one of the most commonly used ones. This review provides a comprehensive overview of past debris flow modelling applications in an alpine environment with their main characteristics, including study location, debris flow magnitude, simulation resolution, and Voellmy-fluid friction model parameter ranges, (i.e. μ and ξ). A short overview of each study is provided. Based on the review conducted, it is clear that RAMMS parameter ranges are relatively wide. Furthermore, model calibration using debris-flow post-event survey field data is the essential step that should be done before applying the model. However, an overview of the parameters can help to limit the parameter ranges. Particularly when considering the similarity between relevant case studies conducted in similar environments. This is especially relevant should the model be applied for estimating debris-flow hazard for potential future events. This model has been used mostly in Europe, (i.e. Alpine region) for modelling small and extremely large debris flows.

scholarly journals Regional-scale GIS-models for assessment of hazards from glacier lake outbursts: evaluation and application in the Swiss Alps

2003 ◽  
Vol 3 (6) ◽  
pp. 647-662 ◽  
Author(s):  
C. Huggel ◽  
A. Kääb ◽  
W. Haeberli ◽  
B. Krummenacher
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Flow Direction ◽  
Regional Scale ◽  
Satellite Image ◽  
Swiss Alps ◽  
Special Focus ◽  
High Mountain ◽  
Mountain Areas ◽  
Single Flow

Abstract. Debris flows triggered by glacier lake outbursts have repeatedly caused disasters in various high-mountain regions of the world. Accelerated change of glacial and periglacial environments due to atmospheric warming and increased anthropogenic development in most of these areas raise the need for an adequate hazard assessment and corresponding modelling. The purpose of this paper is to pro-vide a modelling approach which takes into account the current evolution of the glacial environment and satisfies a robust first-order assessment of hazards from glacier-lake outbursts. Two topography-based GIS-models simulating debris flows related to outbursts from glacier lakes are presented and applied for two lake outburst events in the southern Swiss Alps. The models are based on information about glacier lakes derived from remote sensing data, and on digital elevation models (DEM). Hydrological flow routing is used to simulate the debris flow resulting from the lake outburst. Thereby, a multiple- and a single-flow-direction approach are applied. Debris-flow propagation is given in probability-related values indicating the hazard potential of a certain location. The debris flow runout distance is calculated on the basis of empirical data on average slope trajectory. The results show that the multiple-flow-direction approach generally yields a more detailed propagation. The single-flow-direction approach, however, is more robust against DEM artifacts and, hence, more suited for process automation. The model is tested with three differently generated DEMs (including aero-photogrammetry- and satellite image-derived). Potential application of the respective DEMs is discussed with a special focus on satellite-derived DEMs for use in remote high-mountain areas.

Comparing a newly developed DEM-based runout model for hillslope debris flows with full-scale experiments and historical events

2020 ◽  
Author(s):  
Adel Albaba ◽  
Niels Hollard ◽  
Christoph Schaller ◽  
Massimiliano Schwarz ◽  
Luuk Dorren
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Residential Buildings ◽  
Full Scale ◽  
Swiss Alps ◽  
Model Parameters ◽  
Historical Events ◽  
Margin Of Error ◽  
Hillslope Debris Flow ◽  
Good Agreement

<p>The increasing urbanization of mountainous areas increased the risk imposed on residential buildings and infrastructure. In Switzerland, shallow landslides and hillslope debris flows are responsible every year for high infrastructure damage, blocking of important highways, evacuations and deaths. Up till now, the assessment of these processes has been mainly based on the experience of experts, especially in the assessment of their run-out extent and expected damage. In this research we present a new computationally efficient Discrete Element Model (DEM) which has been developed for the aim of simulating the run-out of hillslope debris flows.</p><p>YADE-DEM open source code has been extended and an elasto-plastic adhesive contact law have been implemented, which partially account for the presence of the fluid composed of water and find material. This is achieved through the adhesive aspect of the contact law, which would indirectly take the presence of such fluid into account, as this fluid would increase the cohesion of the flowing mass. A parametric study has been carried out to define the most sensitive model parameters, which were found to be the microscopic basal friction angle (Φ<sub>b</sub>) and the ratio between stiffness parameters (loading and unloading) of the flowing particles <img src="data:image/png;base64,%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" alt="">. Data of full-scale experiments of hillslope debris flows were used to compare the flow kinematics with the model’s prediction. A good agreement between the model and experiments was observed concerning the mean front velocity (average margin of error of 8%) and the maximum applied pressure (average margin of error of 5%), with less agreement of the flow height (average margin of error of 13%). Detailed comparisons of pressure evolution between different selected experiments and simulations revealed the model’s capability of reproducing observed pressure curves, especially during the primary loading phase, leading to maximum pressure.</p><p>In order to test the model’s prediction of run-out distance of hillslope debris flow, hundreds of past hillslope debris flow events in the Swiss Alps were analyzed and 30 cases were selected representing different situations (i.e. different release volumes, slopes and forest cover). Due to the discrete nature of results in YADE, a GIS algorithm was developed in order to create envelopes representing the temporal evolution of the simulated propagating processes, which were compared to the those of the historical events. Results of the comparison revealed that, with the calibration of the two sensitive parameters in YADE, a fair to very good agreement was observed between the envelopes of the model and those of historical events for 87% of the tested cases. Difficulties in reproducing the envelopes of the rest of the cases are linked to the uncertainties in the mapping of the envelopes of past events, the role of the forest which is not taken into account in the model, and the lack of direct representation of fluid in the model.</p>

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