Formation Of Landslide Dams Research Articles

Formation and breach of the giant Cuola landslide dam and their impacts on the landscape evolution of river valley in the Jinsha River, southeastern Tibet

Formation and breach of the giant Cuola landslide dam and their impacts on the landscape evolution of river valley in the Jinsha River, southeastern Tibet

A global-scale applicable framework of landslide dam formation susceptibility

The formation and failure of landslide dams is an important and understudied, multi-hazard topic. A framework of landslide dam formation susceptibility evaluation was designed for large-scale studies to avoid the traditional dependence on landslide volume calculations based on empirical relationships, which requires comprehensive local inventories of landslides and landslide dams. The framework combines logistic regression landslide susceptibility models and global fluvial datasets and was tested in Italy and Japan based on landslide and landslide dam inventories collected globally. The final landslide dam formation susceptibility index identifies which river reach is most prone to landslide dam formation, based on the river width and the landslide susceptibility in the adjacent delineated slope drainage areas. The logistic regression models showed good performances with area under the receiver operating characteristics curve values of 0.89 in Italy and 0.74 in Japan. The index effectively identifies the probability of landslide dam formation for specific river reaches, as demonstrated by the higher index values for river reaches with past landslide dam records. The framework is designed to be applied globally or for other large-scale study regions, especially for less studied data-scarce regions. It also provides a preliminary evaluation result for smaller catchments and has the potential to be applied at a more detailed scale with local datasets.

Redundancy and hierarchical cluster analyses for characterizing geomorphic features contributing to the formation of landslide dams

Redundancy and hierarchical cluster analyses for characterizing geomorphic features contributing to the formation of landslide dams

Influence of tectonic effects on the formation and characteristics of landslide dams on the NE Tibetan Plateau: a case study in the Bailong River Basin, China

Influence of tectonic effects on the formation and characteristics of landslide dams on the NE Tibetan Plateau: a case study in the Bailong River Basin, China

Distribution and Stabilization Mechanisms of Stable Landslide Dams

Landslide dams, especially stable landslide dams, have been recognised as important contributors to regional geomorphological evolution. The eastern edge of the Tibetan Plateau provides good conditions for the formation of stable landslide dams. To identify stable landslide dams on the eastern margin of the Tibetan Plateau, the Google Earth Engine (GEE) was first used to map water surfaces in the study area. Then, stable landslide dams were identified using high-precision remote sensing images provided by Google Earth. A field investigation and a sampling of typical stable landslide dams were also adopted to characterise the landslide dams. The results show that 101 stable landslide dams are present in the study area, covering an area of 27.75 × 104 km2. There are four types of stable landslide dams, as follows: (1) landslides, (2) rock avalanches, (3) moraines, and (4) debris flows. The morphological parameters of a dam, which include dam height, dam width, dam volume, and catchment area, can be fitted with different relationship curves, with respect to the number of landslide dams. The source areas of landslide dams are generally located in the upper-middle and upper sections of adjacent mountains. The stability of a landslide dam is mainly controlled by the structure of the dam and the relationship between the dam volume and catchment area. Structurally, large rocks with large particle sizes are difficult to activate using river water and the large gaps between the rocks provide sufficient channels for the flow of river water. In regard to the relationship between the dam volume and catchment area, a river with a small catchment area in the study area is commonly blocked by a large dam volume. This study provides a unique opportunity to study the spatial distribution and clarify the factors influencing the stability of stable landslide dams.

The Art of Landslides: How Stochastic Mass Wasting Shapes Topography and Influences Landscape Dynamics

AbstractBedrock landslides shape topography and mobilize large volumes of sediment. Yet, interactions between landslide‐produced sediment and fluvial systems that together govern large‐scale landscape evolution are not well understood. To explain morphological patterns observed in steep, landslide‐prone terrain, we explicitly model stochastic landsliding and associated sediment dynamics. The model accounts for several common landscape features such as slope frequency distributions, which include values in excess of regional stability limits, quasi‐planar hillslopes decorated with straight, closely spaced channel‐like features, and accumulation of sediment in valley networks rather than on hillslopes. Stochastic landsliding strongly affects the magnitude and timing of sediment supply to the fluvial system. We show that intermittent sediment supply is ultimately reflected in topography. At dynamic equilibrium, landslide‐derived sediment pulses generate persistent landscape dynamism through the formation and breaching of landslide dams and epigenetic gorges as landslides force shifts in channel positions. Our work highlights the importance of interactions between landslides and sediment dynamics that ultimately control landscape‐scale response to environmental change.

Effect of the Fracturing Degree of the Source Rock on Rock Avalanche River-Blocking Behavior Based on the Coupled Eulerian-Lagrangian Technique

In this study, the effect of the fracturing degree of the source rock on rock avalanche river-blocking behavior was investigated. The study included the analysis of mass movement behavior, impulse wave behavior, and the formation of landslide dams. The study included a series of simulations of rock avalanche river-blocking based on the coupled Eulerian-Lagrangian (CEL) technique. Prior to the simulation, a water column collapse model was applied to validate the use of the CEL technique on fluid-structure interaction, and to calibrate the material parameters. The source rock in the rock avalanche simulation was cut by different groups of structural planes, with the number of 0 × 0 × 0, 1 × 1 × 1, 4 × 4 × 4, 9 × 9 × 9, 14 × 14 × 14, 19 × 19 × 19 in each dimension, respectively, to represent different fracturing degrees, on the premise of the same volume and shape of the source rock. The simulation results showed that the sliding mass exhibited structure stabilization, such that the structure of the sliding mass gradually stabilized to a steady status over time, in the mass movement process. The structure stabilization made the center of the sliding mass constantly decrease, and provided a higher speed of movement for the rock avalanches with higher fracturing degrees of the source rock. As for the impulse wave behavior, with the increase in the fracturing degree of the source rock, the maximum kinetic energy of the water decreased, and the maximum height and propagation speed of the impulse waves decreased, which indicated that the maximum height and the propagation speed of the impulse waves were positively correlated with the maximum kinetic energy of the water. In regard to the formation of the landslide dams, when the fracturing degree of the source rock was low, the shape of the landslide dam was very different. With the increase of the fracturing degree of the source rock, the shapes of the landslide dams stabilized, and varied slightly after the fracturing degree of the source rock reached a threshold value.

Non-Monotonic Relationships between Return Periods of Precipitation Surface Hazard Intensity

Hazardous surface processes such as floods and mass movements are often induced by a common trigger such as extreme precipitation. The relationship between the intensity of the trigger and the surface hazard is generally assumed to be monotonically increasing (increasing precipitation never decreases hazard intensity). The validity of this assumption of complex multi-hazard events has not been thoroughly investigated. In this research, the relationship between cumulative precipitation and hazard intensity was investigated by a simulation of 50 return period precipitation events on the Carribean island Dominica. Here, several tropical hurricanes have induced events with (flash) floods, slope failure, debris flows and landslides within the past decades. Results show that complex multi-hazard interactions break the common assumption for the relationship between trigger and hazard intensity. In particular, landslide dam formation and mass movement dilution result in hazard intensities that are not a one-to-one increasing function of trigger intensity. Spatial variability in this behavior is quantified using a rank-order correlation coefficient between trigger return period and hazard return period. Since trigger and hazard return periods are, in the study case, not approximately equal, the hazard for a specific location can not be classified based on trigger return period. This has implications for risk calculation and decision making related to disaster risk reduction.

Quantitative risk assessment of two successive landslide dams in 2018 in the Jinsha River, China

Two large successive co-site landslide dams blocked the Jinsha River in the Sichuan Province of China in 2018. A quantitative risk analysis was carried out to quantify potential human and economic losses resulting from the failure of these dams, especially the interaction between the co-site landslide dams, and to further investigate the influence of digging a diversion channel on risk mitigation. Flood routing for three scenarios (i.e. after the first dam formation, when the second landslide mass was added, and with a diversion channel after failures) were simulated using HEC-RAS. The human and economic losses were evaluated using a human risk assessment model together with empirical formulations. The results show that the risk of breaching floods had increased significantly after the second co-site landslide dam formation on the pre-existing loose deposits of the first dam. This amplification effect of outburst floods was so great that the peak outflow resulting from the breaching of the second landslide dams was more important, leading to greater economic losses than those resulting from the breaching of the first dam. However, the expected loss of life caused by the breach of the two landslide dams appeared small because of the sufficient time lag provided by the long distance between the residential area and the dam site. The simulations also outline the importance of the diversion channel in decreasing the peak outflow rate and hence downstream risks. A parametric analysis shows that a deep channel with a moderate longitudinal gradient can significantly decrease the peak outflow discharge at the dam site. Flood intensity and risks to downstream towns did not change because of the relatively small attenuation rate of the peak outflow rate. However, a shorter height of the residual dam can be obtained by optimizing the diversion channel, and the amplification effects of such co-site dam can be significantly reduced in the future.

Probabilistic hazard assessment of landslide-induced river damming

Landslide-induced river damming poses a considerable threat to the safety of humans and infrastructure. Prediction of landslide-induced river damming is of great significance for quantitative risk assessment and emergency response planning. However, owing to the large uncertainties embedded in the input parameters and dynamic numerical models, a reliable physically based prediction of landslide dam formation is still challenging. In this study, we proposed a probabilistic framework to predict rockslide-induced river damming and its associated barrier lake. Both parameter and model uncertainties were considered to reproduce the run-out process and the deposition behavior of the Baige landslide based on dynamic numerical simulation, while calibrating the input parameters through a sequential Bayesian back analysis. The first slide of the Baige landslide was considered to calibrate the input parameters with observations at several deposition depths. The proposed method was validated by predicting the second slide-induced river damming using the calibrated results from the first slide. Furthermore, the second slide with deposition depth observations was employed to update the input parameters again. Through the sequential Bayesian back analysis, the probability of the river damming induced by the potentially unstable rock masses was predicted, which yielded a hazard zonation map of the barrier lake exceeding various water levels. This hazard zonation map may be employed to guide quantitative risk assessment and corresponding emergency response plans for future landslide-induced upstream backwater-inundation.

Experimental Study on the Accumulation Characteristics and Mechanism of Landslide Debris Dam

According to physical model tests, we analyzed the accumulation characteristics of landslide dams formed under three different slope characteristics, namely, uniform slope, parallel slope, and intersecting slope and investigated the accumulation mechanisms of the debris dams. The relationship between slope types and accumulation characteristics was also explored using the tracer particle analysis method. The damming process and accumulation mechanism of the landslide dam were changed with slope conditions, which lead to the difference in the accumulation characteristics of the dam, especially in transverse cross-sectional shape and grain size distribution. The transverse cross-sectional shape of the landslide dams formed by different slope conditions can be divided into three categories: the flat pattern, unidirectional pattern, and undulating pattern. The characteristics of the slope body are closely related to those of the landslide dam with respect to debris distribution. The debris distributions in the longitudinal and transverse directions of the slope body are consistent with those in the longitudinal and sliding regions of the dam. A general inverse grading characteristic of debris gains occurs in the vertical direction of landslide dams. For the uniform and parallel slopes, obvious inverse grading distribution is induced by overall-starting initiation of the slope body and strong vertical infiltration of the fine sands during the movement. However, inverse grading distribution is generated by the effects of pushing–climbing and lateral infiltration that existed among particles caused by a layered-starting mode for the intersecting slope body. This study provides a basis for the prediction of landslide dam formation and backtracks the initial structure of the slope.

A new global landslide dam database (RAGLAD) and analysis utilizing auxiliary global fluvial datasets

To address the current data and understanding knowledge gap in landslide dam inventories related to geomorphological parameters, a new global-scale landslide dam dataset named River Augmented Global Landslide Dams (RAGLAD) was created. RAGLAD is a collection of landslide dam records from multiple data sources published in various languages and many of these records we have been able to precisely geolocate. In total, 779 landslide dam records were compiled from 34 countries/regions. The spatial distribution, time trend, triggers, and geomorphological characteristic of the landslides and catchments where landslide dams formed are summarized. The relationships between geomorphological characteristics for landslides that form river dams are discussed and compared with those of landslides more generally. Additionally, a potential threshold for landslide dam formation is proposed, based on the relationship of landslide volume to river width. Our findings from our analysis of the value of the use of additional fluvial datasets to augment the database parameters indicate that they can be applied as a reliable supplemental data source, when the landslide dam records were accurately and precisely geolocated, although location precision in smaller river catchment areas can result in some uncertainty at this scale. This newly collected and supplemented dataset will allow the analysis and development of new relationships between landslides located near rivers and their actual propensity to block those particular rivers based on their geomorphology.

Hazard Prediction Method of Landslide Damming and Analysis of a Typical Application

Landslide damming occurs frequently, affects a wide range of areas, and is difficult to predict, thus threatening the safety of human life, properties, and engineering structures. However, the studies on early identification remain at an early stage. This paper proposes a hazard prediction method for landslide damming, which includes prediction models of river blockage, landslide dam geometry, landslide dam stability, and dam breach time. On this basis, the landslide damming hazard can be predicted via ten parameters: the repose angle of the landslide mass, the landslide volume, the landslide discharge, the river discharge, the reservoir capacity of the barrier lake, the bottom width of the valley, two slope angles on both sides of the valley, the valley bed inclination, and the sliding surface dip-angle. The proposed method was examined in relation to a typical case, namely, the Baige landslide damming that occurred in 2018 in China, with the application process presented integrally. The results indicated that the river blockage model predicted that the Baige landslide could form a huge landslide dam, which was fully in line with the actual situation. The landslide dam geometry model provided the predicted value of the height, width, and length, as well as the downstream and upstream angles, of the Baige landslide dam, with the maximum relative error between the predicted values and the true values less than 20%. The prediction results of the landslide dam stability model indicated that when the reservoir capacity of the barrier lake is 280 million m3, the dam could breach. In fact, the dam breach time model predicted that the dam could breach within 38 h after the landslide dam formation, which was 11% less than the actual breach time of the Baige landslide dam. The current study provides a useful theoretical reference and technical support for the early identification, prediction, and warning of the disaster chain of landslide-induced river blocking.

Multi-phase flow simulation of landslide dam formation process based on extended coupled DEM-CFD method

The landslide-river interaction and the impulse waves involved in the landslide dam formation process may not be insignificant and have not been extensively investigated and simulated. This paper presents a numerical investigation on the formation process of landslide dams and resulting free surface flow dynamics in the impacted river via coupled discrete element method (DEM) and computational fluid dynamics (CFD) with the volume of fluid (VOF). The accuracy and validity of the extended coupled method are verified using a series of test cases involving three-phase interaction and free surface evolution. It is then applied to simulate the landslide dam formation processes related to landslide and river flow scenarios of different kinematic characteristics. Furthermore, quantitative analysis is performed to describe the complex evolution of the dam morphology and dynamic evolution of impulse waves. It is found that the impact between the landslide, river flow and valley drives the dam formation process. The landslide velocity considerably influences the propagation of impulse waves, while the river flow velocities control the dam morphology in opposite ways in the upstream and downstream. This research provides a practical modeling framework to understand the formation mechanism of landslide dams and support applications in hazard prediction and mitigation.

A Numerical Study of the Critical Threshold for Landslide Dam Formation Considering Landslide and River Dynamics

Landslide dam formation can be influenced by the erosive capacity of river flow and the dynamic characteristics of the landslide. When the deposition rate of a landslide that reaches a river is higher than the erosion rate of river flow, the landslide can form a dam by blocking the channel. Hence, in this paper, a dimensionless discharge threshold for landslide dam formation considering landslide and river dynamics is established and studied numerically. A two-layer depth-averaged model coupled with an erosion term is presented to simulate river and landslide movements and their interactions. Several numerical cases are simulated to study the influence of landslide and river dynamics on the critical threshold for dam formation by considering some key factors, such as landslide velocity and the angle between the river and landslide transport directions. Through the simulations, three types of landslide intrusion into river can be reflected: a dam forms quickly, a dam forms or does not form close to a critical state, and no dam forms. The results show that these factors together affect the process of dam formation if the difference between the landslide and river discharges is relatively small. All results are helpful to further clarify the formation of such dams for natural hazard prevention under future climate change conditions.

Controls on the formation and size of potential landslide dams and dammed lakes in the Austrian Alps

Abstract. Controls on landsliding have long been studied, but the potential for landslide-induced dam and lake formation has received less attention. Here, we model possible landslides and the formation of landslide dams and lakes in the Austrian Alps. We combine a slope criterion with a probabilistic approach to determine landslide release areas and volumes. We then simulate the progression and deposition of the landslides with a fluid dynamic model. We characterize the resulting landslide deposits with commonly used metrics, investigate their relation to glacial land-forming and tectonic units, and discuss the roles of the drainage system and valley shape. We discover that modeled landslide dams and lakes cover a wide volume range. In line with real-world inventories, we further found that lake volume increases linearly with landslide volume in the case of efficient damming – when an exceptionally large lake is dammed by a relatively small landslide deposit. The distribution and size of potential landslide dams and lakes depends strongly on local topographic relief. For a given landslide volume, lake size depends on drainage area and valley geometry. The largest lakes form in glacial troughs, while the most efficient damming occurs where landslides block a gorge downstream of a wide valley, a situation preferentially encountered at the transition between two different tectonic units. Our results also contain inefficient damming events, a damming type that exhibits different scaling of landslide and lake metrics than efficient damming and is hardly reported in inventories. We assume that such events also occur in the real world and emphasize that their documentation is needed to better understand the effects of landsliding on the drainage system.

The Preservation of Climate‐Driven Landslide Dams in Western Oregon

AbstractBedrock landsliding, including the formation of landslide dams, is a predominant geomorphic process in steep landscapes. Clarifying the importance of hydrologic and seismic mechanisms for triggering deep‐seated landslides remains an ongoing effort, and formulation of geomorphic metrics that predict dam preservation is crucial for quantifying secondary landslide hazards. Here, we identify >200 landslide‐dammed lakes in western Oregon and utilize dendrochronology and enhanced 14C dating (“wiggle matching”) of “ghost forests” to establish slope failure timing at 20 sites. Our dated landslide dataset reveals bedrock landsliding has been common since the last Cascadia Subduction Zone earthquake in January 1700 AD. Our study does not reveal landslides that date to 1700 AD. Rather, we observe temporal clustering of at least four landslides in the winter of 1889/1890 AD, coincident with a series of atmospheric rivers that generated one of the largest regionally recorded floods. We use topographic and field analyses to assess the relation between dam preservation and topographic characteristics of the impounded valleys. In contrast to previous studies, we do not observe systematic scaling between dam size and upstream drainage area, though dam stability indices for our sites correspond with “stable” dams elsewhere. Notably, we observe that dams are preferentially preserved at drainage areas of ∼1.5 to 13 km2 and valley widths of ∼25 to 80 m, which may reflect the reduced downstream influence of debris flows and the accumulation of mature conifer trees upstream from landslide‐dammed lake outlets. We suggest that wood accumulation upstream of landslide dams tempers large stream discharges, thus inhibiting dam incision.

An experimental determination of the relationship between the minimum height of landslide dams and the run-out distance of landslides

Landslides frequently occur on mountain slopes due to earthquakes and rainfall. When a landslide occurs near a river, the landslide mass moves at a certain speed towards the river channel and eventually stops at the channel either due to frictional resistance or by being blocked by the upslope on the opposite bank of the river. If the width of the river channel at the landslide site (BW) is narrow and the volume of the landslide (VL) is sufficient, the landslide may block the river channel, resulting in landslide dams. Landslide dam is a significant hazard in mountainous area, when dam failure will cause severe destruction and affect downstream area. The frequency, scale, and disaster of landslide dam will be more serious than before based on global climate change. To reduce disasters caused by landslide dams, rapid assessments of dam stability and dam-break discharge must be conducted in the early stages of the formation of landslide dams. One of the essential parameters for these assessments is the minimum height of the landslide dam ( $$ {H}_{D_{\mathrm{min}}} $$ ). However, landslides may occur in remote, inaccessible mountainous areas where the geometrical parameters of landslide dams may not be immediately obtained, making it difficult to perform emergency risk assessments of barrier lakes. The magnitude of $$ {H}_{D_{\mathrm{min}}} $$ changes due to the effects of the run-out distance of the landslide (Lrun ‐ out) and BW, but a quantitative relationship has not been reported in the literature. Hence, this study investigated the effects of VL, the slope angle (θS), the maximum height of the landslide (HL), BW, and other parameters on $$ {H}_{D_{\mathrm{min}}} $$ through laboratory experiments. The relationship between Lrun ‐ out, BW, and $$ {H}_{D_{\mathrm{min}}} $$ was determined, and a dimensionless method for evaluating $$ {H}_{D_{\mathrm{min}}} $$ was established. This method can be applied to predict the minimum height of landslide dams when the position of the landslide is known. Additionally, when landslide dams form but $$ {H}_{D_{\mathrm{min}}} $$ is not known due to difficulties in on-site study, this method can quickly assess the height of the dam and provide an assessment of the risks related to the landslide dam. This greatly reduces the uncertainties associated with the prevention and emergency management of landslide dams, and can assist government authorities to set up the disaster early warning plans of landslide dam under future climate change condition.

Integrating an interferometric synthetic aperture radar technique and numerical simulation to investigate the Tongmai old deposit along the Sichuan-Tibet Railway

Numerous old deposits occur in the Eastern Himalayan Syntaxis, especially on the banks of the Yarlung Tsangpo River and its tributaries, where strong tectonic movement and riverine erosion increase the potential for landslides. The possible future deformation and failure processes of these old deposits and their impacts on the surrounding environment are important research topics. Field investigations and temporarily coherent point interferometry synthetic aperture radar (TCP-InSAR) monitoring show that the Tongmai old deposit is prone to catastrophic failure and landsliding. A geomorphological analysis and the related dating results indicate that the Tongmai old deposit consists of residual colluvial or early moraine debris and was formed later than 11.06 ± 0.94 ka BP. The TCP-InSAR analysis indicates that creep deformation is present within the deposit and that this creep is closely related to the precipitation and activity of nearby faults, which may cause slope failure and lead to landslide dam formation. As a result, this study further predicts the likely scale of a landslide dam through numerical simulations. In the worst-case scenario, a landslide will seriously block the Parlung Tsangpo River and form a dam with a height of 100–152 m and a length of approximately 2.4 km. The Tongmai old deposit will likely form a geohazard chain including landslides, barrier lakes, and outburst flooding. Finally, this paper discusses the influence of the Tongmai old deposit on river and landscape evolution.

Experimental investigation on the formation process of landslide dams and a criterion of river blockage

River blocking caused by landslide dams is a common geological disaster in mountainous regions worldwide, threatening the safety of human lives and infrastructure. However, studies on the formation process of landslide dams and the criteria of river blockage are still at an early stage. This paper built a laboratory-scale experimental apparatus for simulating the formation and evolution process of landslide dams, and then carried out a total of 29 experiments. It analyzed the common evolution stages of river blocking, including landslides, dam formation, and dam breaching in detail. Then, we investigated the influences of the landslide volume, the landslide discharge, and the water flow rate on a criterion and the time length of river blockage. The experimental results suggest that the formation condition of a landslide dam is related to the ratio of the landslide discharge to the water flow rate. Based on this understanding, we proposed a dimensionless River Blockage Criterion (RBC) to judge the formation of landslide dams. The criterion indicates that when RBC > 1.5, a landslide dam may form; otherwise, a landslide dam may not form. Additionally, the time length of river blockage was found to be related to the landslide volume and the water flow rate. Subsequently, we proposed a model for predicting the time length of river blockage and verified it by the 29 experimental results. The Baige River-blocking event, which occurred on the Jinsha River, China, in 2018, was used as a case study to further verify the RBC and the proposed model. The results show that the proposed RBC agreed well with reality, and the percentage difference between the calculated and the actual time length of river blockage was 11%. The findings of this study could contribute to the early warning and emergency response of river-blocking disasters.