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On September 16, 2020, the combination of mining activities and constant rainfall triggered a long runout landslide in Jianshanying area, Guizhou Province, China, causing a landslide of approximately 80×104 m3 of rock and soil to slide down and form a debris flow. The maximum movement distance of the landslide reached 1 km, with a maximum height difference of about 300 m. Many houses and two roads were destroyed, fortunately without causing casualties. In this study, detailed field investigation combined with the UAV aerial photography were conducted to obtain the geological setting and the digital elevation model of the landslide region. Subsequently, the dynamic model DAN3D was utilized to study the dynamic characteristics and deposit distribution of the Jianshanying landslide. Simulated results were found to match the actual situation well, and the Frictional-Voellmy rheology was identified as an accurate tool for simulating the long runout landslide. Based on the numerical parameters determined from the inversion work, the sliding process and possible travel distance of the potential landslide were simulated. The findings from this study will be helpful aid in predicting landslide runout in high-altitude regions, particularly for the residents in the potential danger zone of the Jianshanying landslide.

On September 16, 2020, the combination of mining activities and constant rainfall triggered a long runout landslide in Jianshanying area, Guizhou Province, China, causing a landslide of approximately 80x104 m³ of rock and soil to slide down and form a debris flow. The maximum movement distance of the landslide reached 1 km, with a maximum height difference of about 300 m. Many houses and two roads were destroyed, fortunately without causing casualties. In this study, detailed field investigation combined with the UAV aerial photography were conducted to obtain the geological setting and the digital elevation model of the landslide region. Subsequently, the dynamic model DAN3D was utilized to study the dynamic characteristics and deposit distribution of the Jianshanying landslide. Simulated results were found to match the actual situation well, and the Frictional-Voellmy rheology was identified as an accurate tool for simulating the long runout landslide. Based on the numerical parameters determined from the inversion work, the sliding process and possible travel distance of the potential landslide were simulated. The findings from this study will be helpful aid in predicting landslide runout in high-altitude regions, particularly for the residents in the potential danger zone of the Jianshanying landslide. [ABSTRACT FROM AUTHOR]

Numerical models have become a useful tool for predicting the potential risk caused by debris flows. Although a variety of numerical models have been proposed for the runout simulation of debris flows, the performances of these models in simulating specific events generally vary due to the difference in solving methods and the simulation of the entrainment/deposition processes. In this paper, two typical depth-averaged models have been used to analyze a well-documented debris-flow event that occurred in the Cancia basin on 23 July 2015. The simulations with and without bed entrainment are conducted to investigate the influence of this process on the runout behavior of the debris flow. Results show that the actual runout can be reproduced only by considering bed entrainment. If basal erosion is not taken into account, part of the debris mass deviates from the main path and both models predict unrealistic bank overflows not observed in the field. Moreover, the comparison between measured and simulated inundated areas shows that both models perform generally well in the terms of simulating the erosion-deposition pattern, although the DAN3D model predicts a greater lateral spreading and a thinner depositional thickness compared to Shen’s model. A simple numerical experiment obtains similar consequences and further illustrates the possible reasons that cause these differences.

On 24 June 2017, a rockslide-debris avalanche occurred in Xinmo Village, Maoxian County, Sichuan Province, China. The displaced materials traveled approximately 2.6 km and caused 83 casualties. Combined with the field investigation, seismic signal, and numerical simulation, the dynamic process and deposit characteristics of the Xinmo landslide were analyzed. Based on the Arias intensity and Hibert time–frequency analysis of the seismic signal, the Xinmo landslide is determined to have a total duration of 120 s and with three-stage dynamic processes, namely, the initial accelerating stage (50 s), erosion impact stage (50 s), and accumulation stage (20 s). Then, taking the field investigation results, the total duration, and kinetic parameters inverted from the seismic signal as criteria, the DAN3D (Dynamic Analysis of Landslides) was employed to reconstruct the dynamic process of the Xinmo landslide. The results show that the erosion and deposit depth distributions obtained from the simulation are in agreement with the pre- and post-landslide DEM (digital elevation model) data and field results. Further, the three-stage dynamic processes (40 s, 60 s, 20 s) obtained from the numerical simulation are also close to the seismic analysis results. In this study, the results of the field investigation and seismic analysis provide a more detailed set of inversion criteria for the numerical simulation work, which contributes to reconstructing the dynamic processes of the Xinmo landslide more accurately. Based on the approach of multi-source data collaboration in this paper, those landslides that lack direct observation data can be better understood and the numerical parameters used for landslide dynamics inversion are better calibrated, which can be applied to predict the runout behavior and disaster scope of potential landslides in the immediate area. [ABSTRACT FROM AUTHOR]

This article takes the Benduo high deformed body in the upper reaches of Yigong Zangbo as an example, combined with the methods of field ground survey, UAV integrated photographic survey, optical remote sensing dynamic investigation and numerical simulation prediction, the development characteristics and possibility of the Benduo high deformed body are analyzed. Predict and analyze the risk of forming a disaster chain. The results of the study are as follows: (1) The Benduo high-position deformable body is located in the fault, the rock mass is broken, the rock mass structural surface is developed, and the strength is low. At present, there are 12 small collapses and 64 cracks in the strong deformation of Benduo's high deformation body. (2) According to the interpretation results of InSAR, it is found that the Benduo high-position deformable body has two deformation areas. Among them, the BX1 deformation area is larger and the maximum deformation rate reaches 85 mm/a. Once it loses stability and slides, it has a higher risk of blocking the river. (3) Prediction and analysis of the risk of the deformed body after the instability shows that the Benduo high-level deformed body will block the Yigong Zangbu after the instability, the average thickness of the accumulation body is 90 m, and the backwater length of the dammed lake is 25 km. The backwater area formed by the blockage of the dam poses a higher threat to the downstream villages and towns after the failure of the upstream Zhongyu Village. (4) According to the risk characteristics of the dam body, the treatment plan for the excavation of the spillway tunnel is discussed.

On October 17, 2018, a massive ice avalanche-debris flow occurred in the Sedongpu Basin on the left bank of the Yarlung Zangbo River in Tibet. The sliding mass scoured the glacial deposits and loose deposits in the gully bed and then transformed into a debris flow. Eventually, a barrier dam was formed and blocked the Yarlung Zangbo River, which seriously affected the safety of residents and social and economic development. In this paper, a three-dimensional numerical simulation of this event was performed based on remote sensing. A dynamic analysis (DAN3D) model was utilized to analyze the dynamic characteristics of sliding mass, and the Frictional-Voellmy composite model was selected to reproduce debris flow accumulation characteristics, movement speed, and scraping depth. The simulation results are consistent with the actual survey results and have good reliability. Based on field investigation, the electrical resistivity tomography method was used to reveal the post-event accumulation characteristics of the ice avalanche-debris flow in Sedongpu gully. The results showed that DAN3D could well simulate the accumulation shape and maximum thickness of sliding mass, which verified the effectiveness of DAN3D simulation. The results of the study can help forecast similar events and provide new research ideas for the mechanism research of such disasters for future prevention and control projects.

Tailings ponds are composed of residual mining sediments and represent a high risk due to their mechanical instability. A tailings dam break can cause extensive damage to the safety of downstream residents and the surrounding environment. This paper introduces a collapse of the tailings dam that occurred in Tonglüshan, Daye, Hubei, China. To examine the rheological properties and evolutionary mechanism of the tailings slurry from initiation to run-out, a numerical simulation was conducted through a dynamic model (DAN3D) to simulate the run-out behaviors of the tailings slurry based on the models and parameters obtained from the rheology tests. The results indicate that the slurry properties are highly consistent with the Bingham model during the movement process, and the rheological parameters of a slurry with a solid mass concentration of 74% provide the best performance in simulating this catastrophe. During the process of the Tonglüshan tailings dam break, the duration of the movement is estimated at approximately 100 s, with a maximum velocity of 22 m/s. The final distribution of the tailings deposit obtained from simulated results is in good agreement with the actual situation, indicating the validity of the selected rheological models and parameters. It is expected that the method of combining the DAN3D model with rheology tests could help clarify the propagation process of the similar tailings dam break and thus improve the accuracy of hazard prediction. [ABSTRACT FROM AUTHOR]

On January 27, 2021, a small-scale loess landslide occurred in Dangchuan Village, Yongjing County, Gansu Province, China. Timely monitoring and warning helped to prevent any casualties. The sliding mass of the Dangchuan landslide fell in two stages with an interval of 24 s and lasted for a total of 31 s. Eventually, the Dangchuan landslide had a descent height of approximately 120 m and a sliding portion stretching approximately 350 m. The landslide volume was approximately 3 × 104 m3. Based on the investigation of different stages of the Dangchuan landslide and the characteristics of the deposition area, the induction of this landslide was attributed to the effect of frozen stagnant water. Following field investigation of the landslide source and crack areas, a potential sliding mass model with a volume of 5 × 104 m3 was obtained via calculation. To predict the disaster scope of potential landslides, we first used DAN3D software to invert this Dangchuan landslide. Then, based on the numerical model parameters obtained from the inversion, the sliding accumulation process of the potential slide mass was simulated. The results showed that the maximum disaster scope of the potential slide mass would be larger than that of the Dangchuan landslide. The new deposit would cover an area of approximately 3.5 × 104 m2, with a thickness in the range of 0–6 m. The new deposition area would expand by approximately 50 m in the long-axis direction compared to the Dangchuan landslide, impacting the houses and roads. The DAN3D prediction results of the disaster scope will help residents in the potential danger zone evacuate in advance, reducing unnecessary damage. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Geological Hazard & Control is the property of China Institute of Geological Environmental Monitoring (CIGEM) Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study determines the runout behavior (Attabad landslide, Hunza, Pakistan) of one of the biggest landslides in Pakistan's history, along the highest and strategically most important highway of the world. On January 4, 2010, at 08:36 local time, 45 Mm3 of rock mass flowed down the hill slope for 1060 m and fell in Hunza River, thus blocking the river's flow and making an artificial dam. This paper examines the landslide's failure process based on seismic data obtained from a published paper. The average velocity of the slide was found to be 14.32 m/s. To better understand the landslide dynamics and failure phenomena, a numerical simulation was conducted using DAN3D to simulate displaced materials' runout behavior. Simulation results indicate that the slope's failure lasted for 70 s, which is in good agreement with seismic wave recordings of 70 s. The combined frictional–Voellmy model obtained the most accurate results for simulation. Further, to verify the results, another simulation was run using RAMMS debris flow software; it was found that the results of both the software's are in good agreement. It is expected that the selected model and its parameters will help understand similar kind of rock avalanches in the area, which will help concerned agencies improve landslide prediction along Karakoram Highway. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Geological Hazard & Control is the property of China Institute of Geological Environmental Monitoring (CIGEM) Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On April 9, 2000, a long run-out landslide occurred in Yigong, Bomi county, Yarlung Zangbo Grand Canyon, China. The displaced materials traveled approximately 10 km with an elevation difference of 3 km, and finally generated a barrier lake at the toe of the mountain. The landslide and the collapse of the associated landslide dam killed 30 people, left more than 100 people missing, and destroyed several bridges. A combined debris avalanche-dam break flood simulation was performed in this study to better understand the long run-out mechanism and behaviors of such an event. The dynamic model DAN3D was used to simulate the run-out process of the sliding mass, while the Computational Fluid Dynamics software FLOW-3D was used to simulate the duration of landslide dam break and subsequent outburst flood propagation. Output data from the DAN3D simulation were used as input parameters for landslide dam modeling in FLOW-3D. Simulated results indicated that the duration of the landslide movement was estimated at 300 s with a maximum velocity of 90 m/s. Also, the maximum flow of the outburst flood at the Tongmai bridge was approximately 130,000 m3/s. The observed phenomena and measured data in situ verified the validity of the numerical simulation. It is expected that the work conducted in this study could help improve the understanding of the chain disaster of the rock slide-debris avalanche and subsequent dam-break flood. [ABSTRACT FROM AUTHOR]

On July 23, 2019, a large catastrophic landslide occurred in Shuicheng, Guizhou, China. It was a rapid and long run-out landslide that resulted in more than 50 casualties. The displaced materials traveled an approximate distance of 1250 m, with a descending height of around 465 m. In this paper, seismic record analyses and numerical simulation were conducted to determine the run-out behavior of the Shuicheng landslide. To determine the main characteristics of the landslide, geological and climatic settings were obtained by conducting a detailed field survey. The DAN3D model was used to simulate the propagation and run-out process of the landslide. It was observed that a combined Frictional-Voellmy model provides assuring results in simulating the Shuicheng landslide. The total duration of the landslide is 60 s with an average velocity of 20 m/s. The maximum velocity is estimated to be 40 m/s along the right bank of the valley, while a high initial velocity of 24 m/s was recorded at the initiation of the landslide. Seismic records obtained from the nearby seismic stations were used to calculate the location of the event and interpret the dynamic process of the landslide. The Arias intensity, Hilbert-Huang transform, and Empirical mode decomposition were used to obtain a detailed time history of the landslide. The results of the numerical simulation and seismic record analyses are expected to portray the process of similar landslides. This will improve the accuracy of landslide hazard mapping in the region. [ABSTRACT FROM AUTHOR]

Abstract Since the 1990s, with rapid economic development and urbanization occurring in many countries, the amount of construction and demolition waste (CDW) has also increased. Landfills have become the most commonly used method of disposing of CDW. The safety of landfill slopes is very important. On December 20, 2015, a catastrophic landslide occurred in Shenzhen, Guangdong, Southeastern China. Seventy-seven people were killed, and 33 buildings were buried or damaged. In this paper, the Shenzhen 12.20 landslide is used as an example, and the characteristics of the landfill landslide's post-failure behavior are studied. The following conclusions are made: (1) According to our field investigations, the landslide's motion can be divided into the source area, the propagation area, and the accumulation area. During post-failure motion, loose saturated spoil, which experiences motion similar to that of a slurry flow, and water are the critical factors that cause slope failure and result in a long runout slide. (2) The DAN3D analysis method can satisfactorily reproduce the motion of the Shenzhen "12.20" landslide. (3) A Frictional model can be used for the simulation analysis of the source area. In addition, the Bingham model can be used for the fluidization simulation analysis of the propagation and accumulation areas of a CDW landslide. These conclusions can be used for scientific analysis of CDW landfill landslide hazard zoning and early monitoring and warnings. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

If a slope located near a densely populated region is susceptible to debris-flow hazards, barriers are used as a mitigation method by placing them in flow channels; i.e., flowpaths. Selecting the location and the design of a barrier requires hazard assessment to determine the width, volume, and impact pressure of debris-flow at the moment of collision. DAN3D (Three-Dimensional Dynamic Analysis), a 3D numerical model for simulating debris-flow, has been widely used to perform hazard assessment; however, solely using DAN3D would be both insufficient and inefficient in finding the optimal barrier location. Therefore, the present study developed a framework that interprets the results from DAN3D simulation without considering any barriers. Then, the framework generates hazard assessment maps showing the impact parameters of debris-flow along the flowpath by various algorithms and machine learning methods, such as the k-means clustering algorithm, and also computes the width of the debris-flow, which is not explicitly calculated in DAN3D. A case study of the debris-flow at Umyeon mountain, Korea, in 2011, was used to generate hazard assessment maps. The maps were demonstrated to be a tool to quickly compute the impact parameters for conceptual barrier design with the aim of finding potential barrier locations.

Over the last decades, a movement has begun to reclassify deposits previously misidentified as having origins other than landsliding. The reverse problem of incorrectly assigning deposits a mass movement origin, however, has been addressed less in the landslide community. The Cima Salti Landslide in the Lake Garda region of Northern Italy is a cautionary tale of assuming source areas and volumes. It was traditionally thought to have dammed Tenno Lake in the Middle Ages, and to have a volume of 20–30 Mm 3 . We show through geological field data and simple runout simulations with the codes DAN3D and SHALTOP (which produced comparable results) that the volume of the landslide was likely significantly overestimated in the past, and that it most likely did not dam Tenno Lake, as has been assumed. We propose that a smaller volume landslide (2–5 Mm 3 ) was deposited on stagnant ice melting in situ in the Lateglacial period, a relatively minor event in the complex history of the Magnone valley. This interpretation emphasizes the importance of careful field investigations and assumption validation, at Cima Salti and in a broader context. It also shows the unique capacity of landslide simulation to guide field observation and discriminate mass emplacement processes. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Misinterpretation of rock-avalanche deposits in mountain environments is not uncommon because of the complex interactions between rock avalanches and glaciers. This paper for the first time presents a detailed description of suspicious rock-boulder deposits, which are remnants of a rock avalanche onto a Late Pleistocene glacier. The boulder deposits cover around 1.1 km 2 and are distributed over an area of around 7.5 km 2 and a variety of landforms: three closely nested distinct terminal moraines (0.45 km 2 ) and dislocated terminal moraines (0.34 km 2 ) entirely built up of large boulders, lateral moraines that decrease in elevation over a short distance and connect to the terminal moraines, small patches (0.02 km 2 ) of boulders that occur in islands on a peat-dominated valley floor, and large patches of boulder fields (0.25 km 2 in size) hanging 350 m above the valley floor. The latter are disconnected from any potential source area. 10 Be cosmogenic nuclide ages of the three terminal moraines give an indistinguishable Late Pleistocene age of 13.6 ± 1.4 ka, whereas the largest boulder field that is located on the opposite side of the valley from the failed mountain yields a 10 Be age of 14.1 ± 0.4 ka, which is slightly older but indistinguishable from the moraine deposits within uncertainty margins. All boulder deposits add up to a volume of 31 × 10 6 m 3 . The interpretation of a single rock-avalanche source for those landforms is further confirmed by numerical runout modeling using DAN3D. A failure of the entire volume from Skarfjellet Mountain would result in a runout pattern that is identical to that of the distributed boulder fields when considering that the valley was filled with a glacier around 350 m thick. The rock avalanche would not reach the position of the terminal moraines; however, a glacial re-advance could have transported the boulders to that position. The Late Pleistocene rock avalanche was followed by a Holocene rock avalanche with a volume of 23 × 10 6 m 3 and a typical lobate deposit damming the Innerdalen Valley and creating a lake. 10 Be ages indicate that this event occurred 7.97 ± 0.94 ka ago. Structural measurements performed on high-resolution LiDAR scans show a strongly jointed source rock with three joint sets with dip/dip direction 81/034, 86/331, and 77/354 and a foliation with 22/003. The kinematic of the failures can thus be a combination of small-scale wedge failures and planar sliding on shallow dipping foliation. Our detailed description can enable a better identification and interpretation of similar deposits in other mountain areas. [ABSTRACT FROM AUTHOR]

The Faroe Islands in the North Atlantic Ocean are susceptible to flow-type landslides in coarse-grained highly organic colluvium. Following several hazardous debris avalanche events, research work has been initiated to quantify landslide risk. A central task in this work is to predict landslide runout behavior. From numerical simulation of four debris avalanches, this study provides a first screening of which rheology and appertaining input parameters best predict runout behavior of debris avalanches in the Faroe Islands. Three rheologies (frictional, Voellmy, and Bingham) are selected and used for individual back analysis of the events in the numerical models BING and DAN3D. A best fit rheology is selected from comparing predicted and observed landslide runout behavior. General back analysis to identify the optimal input parameters for the chosen rheology is performed by cross validation, where each debris avalanche is modeled with input parameters from the three other events. Optimal input parameters are found from the model run producing the most accurate runout length and velocity. The Bingham is selected as the best fit rheology, a result differing from similar studies of coarse-grained landslides. A reason for why particularly the frictional rheology proves unsuitable is its tendency to produce too long runout lengths of the low-weight runout material, a result showing important limitations for using the frictional rheology in DAN3D. Optimal Bingham input parameters are τ = 980 Pa and μ = 117 Pa/s. However, future studies performed in 2D models are needed for precise parameterization before results can be used for landslide risk assessment. [ABSTRACT FROM AUTHOR]

Abstract: Around 11.5∗106 m3 of rock detached from the eastern slope of the Santa Cruz valley (San Juan province, Argentina) in the first fortnight of January 2005. The rockslide–debris avalanche blocked the course, resulting in the development of a lake with maximum length of around 3.5km. The increase in the inflow rate from 47,000–74,000m3/d between April and October to 304,000m3/d between late October and the first fortnight of November, accelerated the growing rate of the lake. On 12 November 2005 the dam failed, releasing 24.6∗106 m3 of water. The resulting outburst flood caused damages mainly on infrastructure, and affected the facilities of a hydropower dam which was under construction 250km downstream from the source area. In this work we describe causes and consequences of the natural dam formation and failure, and we dynamically model the 2005 rockslide–debris avalanche with DAN3D. Additionally, as a volume ~24∗106 m3of rocks still remain unstable in the slope, we use the results of the back analysis to forecast the formation of a future natural dam. We analyzed two potential scenarios: a partial slope failure of 6.5∗106 m3 and a worst case where all the unstable volume remaining in the slope fails. The spreading of those potential events shows that a new blockage of the Santa Cruz River is likely to occur. According to their modeled morphometry and the contributing watershed upstream the blockage area, as the one of 2005, the dams would also be unstable. This study shows the importance of back and forward analysis that can be carried out to obtain critical information for land use planning, hazards mitigation, and emergency management. [Copyright &y& Elsevier]

If a slope located near a densely populated region is susceptible to debris-flow hazards, barriers are used as a mitigation method by placing them in flow channels; i.e., flowpaths. Selecting the location and the design of a barrier requires hazard assessment to determine the width, volume, and impact pressure of debris-flow at the moment of collision. DAN3D (Three-Dimensional Dynamic Analysis), a 3D numerical model for simulating debris-flow, has been widely used to perform hazard assessment; however, solely using DAN3D would be both insufficient and inefficient in finding the optimal barrier location. Therefore, the present study developed a framework that interprets the results from DAN3D simulation without considering any barriers. Then, the framework generates hazard assessment maps showing the impact parameters of debris-flow along the flowpath by various algorithms and machine learning methods, such as the k-means clustering algorithm, and also computes the width of the debris-flow, which is not explicitly calculated in DAN3D. A case study of the debris-flow at Umyeon mountain, Korea, in 2011, was used to generate hazard assessment maps. The maps were demonstrated to be a tool to quickly compute the impact parameters for conceptual barrier design with the aim of finding potential barrier locations. [ABSTRACT FROM AUTHOR]