Landslide-induced Tsunamis Research Articles

A novel back analysis framework for the probabilistic risk assessment of subaerial landslide-induced tsunami hazard

A novel back analysis framework for the probabilistic risk assessment of subaerial landslide-induced tsunami hazard

Investigating landslide-induced tsunamis using a low-dissipation Riemann weakly compressible smoothed particle hydrodynamics model

In order to address the complex moving boundary problem and violent free-surface flows involved in the process of landslide tsunamis, this paper proposes a new low-dissipation Riemann-solver-based smoothed particle hydrodynamics (SPH) numerical model. In this model, the complex fluid-rigid slide interaction and friction effects on landslides are handled by an improved motion boundary approach based on a one-sided Riemann scheme. A weighted essentially non-oscillatory (WENO) reconstruction method is introduced to reduce excessive dissipation of the fluid caused by rigid landslide impact. The kernel gradient accuracy is assured by applying the corrected smoothed particle method (CSPM) into a continuity equation. Single-block and multi-block landslide tsunamis in two-dimensional (2D) or three-dimensional (3D) applications are simulated with different particle resolutions, and the results are compared to those of other numerical models and experimental results. The landslide trajectories obtained from the modified boundary model are in good agreements with the experimental values. Free-surface flows variations during the propagation are properly captured in the current simulations without introducing any artificial viscosity term, and the wave peaks exhibit deviations of −14%–10.5% from the experimental values, thus verifying the usability and robustness of the proposed Riemann-SPH model.

Landslide-induced tsunami simulation based on progressive landslide-shallow water equation coupling model: 1946 Aleutian tsunami case

Landslide-induced tsunami simulation based on progressive landslide-shallow water equation coupling model: 1946 Aleutian tsunami case

Numerical investigation of a potential landslide-induced tsunami at the Suofengying reservoir in China

Numerical investigation of a potential landslide-induced tsunami at the Suofengying reservoir in China

One-dimensional numerical model of landslide over high-steep slopes: Theory and verification to the analytical solution

At the steep slope areas, landslide events may suddenly occur due to prolonged heavy rain and seriously affect humans’ lives and their properties. Numerical models simulating landslides help us to predict the real landslide phenomenon effectively because they are not only time-saving compared to physical models but also acceptable accuracy. In this paper, the one-dimensional nonlinear shallow water equations using the global coordinate system are established as the proposed model governing equations. The hybrid finite difference-finite volume method, the implicit method and the automatical time step controlling technique are employed to stably simulate the landslide events over the high-steep slopes. To validate the proposed numerical model to the analytical solution, authors continuously derive the non-dimensional governing equations in one dimension as well as using the global coordinate system. The numerical results are in good agreement with the analytical solution. The proposed numerical model can be used to simulate the landslides and the landslide-induced tsunami events, especially for simulating the high-steep slope conditions.

Submarine landslide-induced tsunami generation in Makassar strait, Indonesia using Non-hydrostatic wave model

Tsunami modelling of potential landslide-induced tsunami in Makassar Strait is carried out to quantify possible damage to the nearby cities. The numerical model is used to represent the wave generation by using NHWAVE model. The simulations consist of a series of scenarios based on distinct size of the landslide volume. Four landslides with volume 5, 8, 70, and 200 km3 are used as tsunami sources in the initiation stage. The sources are evenly distributed in the strait addressing different landslide location. Maximum wave heights of 1.5 m are found in the area between Palu and Bangkir from case 1 and around Talok from case 2 simulations. The empirical run-up calculation of 7.5 m is estimated at the land for the presented wave height. The value significantly elevates the case 3 and 4 proportional to the volume values. The waves impact more than half of coastline with maximum value found in the Sulawesi side. Interestingly, wide and narrow shelf next to Kalimantan Island plays an important role in reducing the tsunami hazard level.

Mesh-free simulation of height and energy transfer of landslide-induced tsunami waves

The landslide-induced tsunami wave poses a threat to human society and the living environment by causing disasters such as run-up of water surfaces and overtopping of dams. In this paper, we systematically investigated the relationship between landslide properties and induced tsunami wave characteristics as well as the energy transfer between the landslide and waves. A meshless smoothed particle hydrodynamics (SPH) framework was presented and validated with four experiments of different landslide types. The validations indicate that the SPH model is capable of reproducing the complex processes of tsunami wave generation induced by both rigid and deformable landslides. Then we perform numerical simulations of 162 landslide-induced waves scenarios with varying landslide deformability, relative initial positions, densities, landslide size, and downstream water depths using the validated SPH model. The results show that the effect of density and initial water depth on the maximum wave height can be disregarded, while the effective landslide volume has a significant effect. The analysis of the kinetic and potential energy of the induced waves reveals that energy transfer occurs rapidly, which mainly increases the potential energy of the water downstream. We also find an exponential relationship between landslide potential energy reduction and maximum wave height. These findings provide valuable insights into the landslide-induced tsunami waves and enhance risk assessment and mitigation efforts.

A Review of Research Methods and Evolution Mechanisms of Landslide-Induced Tsunamis

The research on landslide surge has always been a hot issue in the research of engineering geology, geological disasters and hydraulics in both domestic and foreign circumstances. Based on the research status and achievements of landslide surge, this paper mainly reviews the research methods of landslide surge including numerical simulation methods, theoretical analysis methods and physical methods. The first part summarized the examples of geological disaster surge and the classification, characteristics and influencing factors of geological disaster surge. In the second part, the research methods of landslide surge are summarized. Firstly, the theoretical analysis progress of landslide surge in recent years is summarized. Secondly, the present situation of physical model test is summarized from four aspects: model, surge generation, surge propagation and surge run-up. Finally, the numerical simulation methods are summarized from the generation and propagation of surge. The third part discussed the influence factors of landslide surge. In the next part, the difficult problems and research status of landslide surge are evaluated. Finally, the study of landslide surge is prospected from the perspective of various factors of landslide surge.

Application of Stress Parameter from Liquefaction Analysis on the Landslide Induced Tsunami Simulation: A Case Study of the 2018 Palu Tsunami

The accuracy of numerical simulations of a landslide-induced tsunami depends on the landslide characteristics, such as landslide geometry and geotechnical parameters. However, owing to the difficulty in sampling and measuring submarine landslides, rough assumptions of landslide parameters typically lead to significant uncertainties. In the 2018 Palu event, the earthquake was followed by immediate cascading disasters of coastal subsidence, both land and submarine landslides and a tsunami. This scenario provides opportunities to analyze landslide phenomena on land to characterize the submarine landslide causing the tsunami. This study proposes a new approach of using shear-stress parameters obtained from liquefaction analyses as input for landslide-induced tsunami simulation. To obtain the submarine landslide parameter, using the finite element method we modeled the liquefaction happened in Jono-Oge located near Palu Valley area. The shear-stress in this area was quite small with the range 1.5–3.5 kPa. We found that tsunami simulation yielded better accuracy by applying the stress value range obtained from the liquefaction analysis on land (1.5 kPa) rather than the typically adopted stress value for general cases (20 kPa). The result from the tsunami simulation using two-layer method with identical landslide location and geometry showed that shear-stress value of landslide mass gave quite a significant effect to the tsunami height.

Modeling Landslide-Induced Tsunamis

Modeling Landslide-Induced Tsunamis

Prediction of landslide tsunami run-up on a plane beach through feature selected MLP-based model

We proposed new prediction models based on multilayer perceptron (MLP) which successfully predict the maximum run-up of landslide-generated tsunami waves and assess the role of parameters affecting it. The input is approximately 55,000 rows of data generated through an analytical solution employing slide’s cross section, initial submergence, vertical thickness, horizontal length, beach slope angle and the maximum run-up itself, along with its occurrence time. The parameters are first ranked through a feature selection algorithm and six models are constructed for a 9,000-row randomly sampled dataset. These MLP-based models led predictions with a minimum Mean Absolute Percentage Error of 1.1% and revealed that vertical slide thickness has the largest impact on the maximum tsunami run-up, whereas beach slope angle has minimal effect. Comparison with existing literature showed the reliability and applicability of the offered models. The methodology introduced here can be suggested as fast and flexible method for prediction of landslide-induced tsunami run-up.

A numerical model for the efficient simulation of multiple landslide-induced tsunamis scenarios

Submarine landslides can pose serious tsunami hazard to coastal communities. However, performing a comprehensive landslide tsunami hazard assessment for a given area is in general difficult in view of the large uncertainty associated with tsunamigenic source parameters, which are often only approximately defined, based on estimates of the landslide geometry, slide material properties, and resulting kinematics. Therefore, a Probabilistic Tsunami Hazard Analysis (PTHA) should be performed by considering a large number of cases, which is computationally demanding. Here, we present an efficient model based on solving the linear Mild-Slope Equation with a time-dependent source term representing the seafloor motion. This approach allows carrying out many computations, for a large number of landslide scenarios, in a Monte Carlo (MC) approach framework, at a reduced computational cost compared to other available methods, while still providing physically accurate simulations of most landslide tsunami generation and propagation processes. To further speed-up the MC simulations, a database of elementary solutions is first developed, for many landslide sources of unit amplitude motion over a small seafloor area within the possible landslide footprint. For each unit source, the resulting tsunami elevations are computed and saved at many locations of interest. In the MC simulations, a large number of landslide scenarios are defined by randomly selecting slide parameters within their statistical distributions and each is then simulated for their specific bottom motion using a linear combination of the pre-computed unit sources. Hence, each resulting tsunami is quickly computed at the locations of interest by linear superposition. The paper presents the model validation against two tests cases and describes its novel methodology to perform multiple landslide tsunami scenarios.

Numerical investigation of the hydrodynamic response of an impermeable sea-wall subjected to artificial submarine landslide-induced tsunamis

Numerical investigation of the hydrodynamic response of an impermeable sea-wall subjected to artificial submarine landslide-induced tsunamis

Triggers and consequences of landslide-induced impulse waves – 3D dynamic reconstruction of the Taan Fiord 2015 tsunami event

Natural multi-hazards as landslide-induced tsunamis require a multi-disciplinary approach to analyze the cascade effects that pose a significant threat to mountain communities and the surrounding territory. This paper comprises a detailed study of both the landslide evolution and the wave dynamics of the October 2015 Taan Fiord (Alaska) tsunami event, which represents a highly valuable case study for generic methodology development of single code applications using the numerical software Flow3D and testing its applicability for cascading wave hazard evaluation. First, a geomorphological analysis of the unstable slope is performed by elaborating diverse digital elevation models, where a significant vertical displacement of −90 m is observed before the final collapse, and the influence of listric faults within the slide body results in a bulging of the glacier at the toe. Data from time-series analyses suggests that the glacier retreat (and the reduction of local buttresses) critically destabilized the slope leading to the October 2015 catastrophic failure. The reconstructed landslide volume is estimated to be 49.4 Mm3, where 26 Mm3 entered the fiord and triggered the tsunami. Second, wave dynamics are recreated with Flow3D. Both dense fluid and granular media models are used and compared to verify their performance in initiating the impulse wave, where a measured impact speed ranging between 32 and 49 ms−1 triggers a maximum wave amplitude of about 95–99 m. the maximum run-up of 193 m at the Hoof Hill Fan is recreated with both approaches, but general overestimations (about 9–12%) compared to the observations, in the impact area, are computed for the inundation process. A good approximation of the observed run-up along the entire length of the fiord is found for wave propagation models using the granular media approach. Beyond the Taan-Fiord case study and for evaluation of cascading landslide-induced hydraulic hazard in other settings, this work points out (i) the necessity of using a high temporal resolution of digital elevation models to analyze the multi-stage slope failure and to properly estimate the landslide volume, (ii) the applicability of the applied numerical models to reproduce the wave dynamics of a landslide-induced tsunami event on one code only, and (iii) how these models can be adopted to develop hazard maps related to potential wave hazards in natural basins.

Simulating landslide-induced tsunamis in the Yangtze River at the Three Gorges in China

Landslide-induced tsunamis may cause fatalities, damages and financial losses. In the Three Gorges Reservoir Area of China, several large landslides are still unstable and persistently creeping toward the Yangtze River. In this paper, we investigate the impacts of landslide-induced tsunamis in the Three Gorges Reservoir by using a hybrid numerical approach. One of the largest unstable mass in this area, the Huangtupo landslide, is chosen as the study object. First, the landslide deformation and initiating velocities are obtained by using the finite-discrete element method. The landslide-induced tsunamis and their impacts on shipping on the Yangtze River are then investigated through smooth particle hydrodynamics modelling. Our results reveal that an approximately 80% reduction in shear strength of the tip in the landslide will lead to catastrophic failure of the landslide, with sliding velocities of up to 8 m/s. Subsequently, such a collapse may initiate a river tsunami, propagating up to 9 m on the nearby reservoir banks within 3 km. The impacts on surrounding floating objects, such as surges and sways, heaves and rolls, are up to 110 m, 8 m and 6°, respectively. The simulations indicate that although the likelihood of a catastrophic failure of the whole landslide is low, the partial sliding still poses severe threat to the nearby reservoir banks and shipping on the Yangtze River. Thus, we recommend continuous monitoring as well as landslide early warning systems at this and also other hazardous sites in this area.

Numerical Investigation on Generation and Propagation Characteristics of Offshore Tsunami Wave under Landslide

Tsunamis induced by the landslide will divide into a traveling wave component propagating along the coastline and an offshore wave component propagating perpendicular to the coastline. The offshore tsunami wave has the non-negligible energy and destruction in enclosed basins as fjords, reservoirs, and lakes, which are worth studying. The initial submergence condition, the falling height and sliding angle of slider, are important reference indexes of damage degree of landslide and may also matter at that of the landslide-induced tsunami. Depending on the fully coupled model, the effects of them on the production and propagation of the tsunami were considered in the study. Since the slider used was semi-elliptic, the effect of the ratio of the long axis to the short axis was also analyzed. According to the computational fluid dynamics theory, a numerical wave tank was developed by the immersed boundary (IB) method; besides, the general moving-object module of slide mass was also embedded to the numerical tanker. The results indicate that the effects of the squeezing and pushing of the slider on water produce a naturally attenuated wave at the front of the wave train, and the attenuation becomes more serious with the increase in the initial submersion range of the slider. The effects of the vertical movement of the slider cause the increase in the amplitude of the back of the wave train. As the falling height increases, the large wave height increases when the slider is initially submerged and decreases when it is not initially submerged, except for the accidental elevation of that at smaller falling heights. The results also indicate that the hazard of the subaerial landslide-induced tsunami is greater under a small or large falling angle, and that of the partial subaerial and submarine landslide-induced tsunami is greater under a small falling angle. With the increase in the ratio of the long axis to the short axis, the total induced wave energy decreases and the shape of the wave train proportionally reduces, while the wave propagation mode does not change.

Analysis and modeling of a landslide-induced tsunami-like wave across the Truong river in Quang Nam province, Vietnam

Landslide-induced waves are one of the most disastrous hazards that can post a great threat to human lives and properties. At about 4:00 pm, 5 November 2017, a landslide-induced tsunami-like wave suddenly occurred across the Truong river in Bac Tra My District, Quang Nam province, Vietnam. The water wave destroyed six houses at the opposite bank and caused one person dead and three others injured. This study seeks to investigate the initiation mechanism and process of the landslide and its impulse wave. First, we examined landslide characteristics through site investigations, unmanned aerial vehicle (UAV) surveys, and laboratory testing with a series of standard geotechnical tests on collected soil samples. Then, the initiation and motion of the rainfall-induced landslides were reproduced by the integrated landslide simulation model (LS-RAPID). Finally, a combined computer simulation of the landslide motion and its impulse wave was performed by using a landslide-induced tsunami simulation model (LS-Tsunami). In which, output data from the LS-RAPID was used as input parameters for LS-Tsunami. The analysis shows that the rainfall with very high intensity in a short-time period was the triggering factor of the landslide, which is common factor in the study area. The 12-, 24-, and 48-h accumulative precipitation prior to the landslide recorded to 530, 760, and 950 mm, respectively. In addition, the rainfall trigger presented a typical pattern of rainstorm events in a long duration. Simulation results show that the impulse wave was generated by the landslide mass rapidly entering the river, crossing the river, and directly causing the disastrous damage to the resident area opposite site of the fail slope. The landslide moved down at a maximum speed of 16.4 m/s when its body approached the water surface and generated a maximum wave height of 5 m. There is good agreement between the observed geomorphic evidences and water traces on the site and simulation results of the landslide and its impulse wave. The paper provides a good case study on the understanding of the mechanism and dynamic process of the whole event that significantly contribute to potential landslide hazard assessment and future disaster mitigation in the area.

Remobilized Cordón Caulle 2011 tephra deposits in north-Patagonian watersheds: Resedimentation at deltaic environments and its implications

The Argentinean side of the Andean North Patagonia is drained by several fluvio-lacustrine systems flowing eastwards from their headwaters at the Andes mountains towards large glacial lakes. These watersheds are recurrently affected by the deposition of tephra erupted from the many active Andean volcanos located in the Southern Volcanic Zone. This research focusses on two fluvial systems (Pireco and Totoral, PT) located in Nahuel Huapi National Park, which were severely impacted by the Cordón Caulle 2011 eruption (CC2011). We investigate particularly the resedimentation of pyroclastic materials on their lacustrine deltas and its potential implications considering 1) the deltas morphology and 2) mass-wasting processes developing at the delta fronts. Original tephra fall deposits were registered at Nahuel Huapi National Park in 2011. Based on the isopach map, we performed a GIS-based volume estimation of the deposit for the studied watersheds. Delta plain progradation from 2011 to 2017 was analyzed from satellite images. We studied the temporal evolution of the subaqueous morphology and mass-wasting processes at the delta fronts using high resolution bathymetric grids registered in 2011, 2014 and 2017. During June 2011 the studied watersheds received a tephra input of ~72 x 106m3. The significant progradation experienced by both deltas especially during the first month of the eruption was favored by 1) abundant precipitation at the watersheds concomitant to heavy tephra deposition and 2) the pre-existing subaqueous morphology characterized by a wide, shallow “terrace” bordering PT delta plains. About six years after the beginning of CC2011, 6% of the tephra fallen over the entire basins had been resedimented at the delta environments (terrace and delta front), totalizing ~3 x 106t. Evidence of pre-eruption and/or co-eruptive mass-wasting processes occurring at PT delta fronts was found on November 2011. Up to 30-m thick pyroclastic deposits were accumulated at PT delta fronts since November 2011, burying mass-wasting features at the upper delta fronts. A suspended-sediment collector installed at the prodelta in 2012 detected hyperpycnal currents transporting pyroclastic materials. These currents probably explain the development of mass-movements at high depths, such as the one that displaced and filled up the bottom sediment trap. This frontally-confined landslide initiated at a depth of >60 m and involved tephra and organic materials deposited at the lower part of Totoral delta front. Because of their recent deposition and loose consolidation, we propose that fresh tephra deposits at PT delta fronts could become particularly unstable and represent a potential hazard to failure, especially if a strong earthquake affects the study area in the next years. A landslide-induced tsunami wave generated at these deltas would impact rural settlements located along the coasts of Brazo Rincón and probably reach the coastal city of Villa La Angostura.

A 3D multiple-relaxation-time LBM for modeling landslide-induced tsunami waves

Landslide generated tsunami waves can trigger debris flows or floods which may lead to serious damage to civil structures and endanger life. Therefore, it is important to deeply understand such problems for disaster prevention and mitigation. In this work, a three dimensional multiple-relaxation-time Lattice-Boltzmann model (LBM) is developed for numerically investigating the landslide movement, landslide-water interaction, and water-wave generation and propagation process. We select the LBM based simulation algorithm due to its overall computational efficiency and its capability to deal with complex geometries and topologies. Both aerial and submerged rigid landslide-generated tsunami waves are simulated. The obtained numerical solutions are compared with corresponding experimental data in the literature and the results are in good agreement. It shows that the proposed LBM method is potentially an alternative tool for modeling landslide-generated tsunami waves.

Model Test Research on the Propagation of Tsunamis and Their Interaction with Navigating Ships

The slope of a reservoir area is unstable and can be destroyed by natural disasters, such as strong earthquakes and rainstorms. Landslide bodies that enter the water and generate landslide surges pose serious safety risks to terminals, ships, and hydraulic structures in a reservoir area. After analyzing landslide data in a reservoir area, a series of comparative tests was carried out to investigate the propagation characteristics of landslide-induced tsunamis in channel reservoirs, and the changes in water level values at various monitoring points in the river channel after the landslides entered the water were explored. The effects of landslide width and thickness on the characteristics of landslide-induced tsunamis were analyzed. The main target was a fixed-velocity ship in landslide-swelling water. The complex nonlinear motion characteristics of the ship on the water were studied to determine the safe navigation range.