Landslide Activity Research Articles

Slope stability evolution of a deep‐seated landslide considering a constantly deforming topography

AbstractSlow‐moving deep‐seated landslides are characterised by continuous deformation, constantly changing topography and sliding‐mass geometry. Deformation rates are predominantly controlled by temporal dynamics of pore pressure. Progressing movements typically cause an over‐steepening of a landslide's foot, making these areas more susceptible to secondary slope failures and piggyback slides that, once they occur, change the geometric boundary conditions of a slope. This study presents an integrated topographic monitoring and geomechanical modelling approach, which is suitable for both model‐based replication of the landslide's hydro‐meteorological drivers and assessment of the long‐term effect of topographic changes on the stability behaviour of a large deep‐seated landslide. Parametrised at the Vögelsberg landslide (Tyrol, Austria) the integrated approach quantified considerable mass relocations between 2007 and 2020 at the landslide's foot and assessed respective effects on slope stability. Additionally, scenarios of past and future topographies were reconstructed and projected. Mass relocations of the order of 25 000 m3 were assessed between multiple airborne laser scanning acquisitions covering a period of 13 years. Based on annual uncrewed aerial vehicle laser scanning campaigns, area‐wide 3D displacements were analysed, exceeding a magnitude of 200 cm a−1 at small parts (2.500 m2) on the steeper foot of the active landslide. The main landslide body (0.28 km2) moves considerably slower with movements of 2–10 cm a−1. Besides spatio‐temporally varying hydrological drivers, topographic changes can have a severe impact on slope stability and therefore modify the spatiotemporal activity of the landslide. It is shown that, besides the hydrometeorological drivers, the varying elevation of the landslide's toe is a key parameter determining the long‐term trend of slope stability. With the presented approach the formation and evolution of the Vögelsberg landslide can be understood and explained.

Tsunami Potential Prediction with Artificial Neural Network

Natural disasters are caused by biological factors such as earthquakes, tsunamis, and landslides. One of the destructive natural disasters that can cause considerable losses in terms of casualties and the economy is the tsunami. A tsunami is a series of tall or long waves in shallow seas. Various tsunami triggers include earthquakes, volcanic activity, and underwater landslides. This study aims to predict tsunamis with an Artificial Neural Network, which is a part of Machine Learning. Artificial Neural Network (ANN) is a model that has the same characteristics as biological neural networks. The process resembles the work of a neural network, which processes incoming information through neurons—using Multi-Layer Perceptron with five input parameters, two hidden layers, and one output. The ANN model can predict a tsunami potential in a country by 81%.

Large landslide of the hyperarid Central Western Andes triggered during a humid period of the Late Pleistocene (ca. 19°S; northern Chile)

AbstractThe western flank of the Central Andes offers a unique geomorphological record of large paleolandslides that are well preserved on long time‐scales (i.e. ≥Pleistocene) due to the long‐lasting aridity of this region. However, the lack of chronological constraints on those landslides limits our understanding of the respective role of tectonics and climate on their triggering. Here, we report new 10Be surface exposure dating obtained on one of those giant slope‐failures: the Limaxina landslide (northern Chile, 19°S). Five tightly grouped exposure‐ages (one outlier discarded) point to a single landslide failure at 80 ± 4 ka. This timing being consistent with others local records of a wet episode in the Atacama Desert, it suggests a primary role of climate‐forcing on landslide activity in this region, calling to further slope failures dating in the arid Central western Andes to explore landscapes responses to Quaternary climate oscillations and extreme events.

Landslide mechanism and stability of an open-pit slope: The Manglai open-pit coal mine

A clear understanding of landslide mechanisms and stability analyses is of great significance for landslide monitoring, prediction, and control. A large-scale end wall landslide occurred and its area reached 47,752 m2 on August 7–20, 2020, in the Manglai open-pit coal mine, China. In this paper, the engineering geological survey, mechanical test, large-deformation finite element numerical method, limit equilibrium method and analytical formula are used to analyze how the groundwater level rise caused this end wall failure and landslide. The engineering geological conditions, hydrogeological conditions, landslide activity signs and physical and mechanical parameter calibration of the sliding mass are investigated in detail and tested. Three-dimensional and two-dimensional numerical models of slopes are established, and an analytical formula calculation method to calculate the factor of safety (FoS) is proposed when sliding cracks are located on the top and toe of a slope. The results indicate that the fault fracture zone, soft strata, continuous heavy rainfall, and groundwater were the main contributors to this landslide. The three-dimensional numerical calculation results are consistent with the deformation and failure process of the slope observed in the field, which shows a retrogressive progressive failure mode. The calculation results of SLOPE/W and the analytical formula are consistent; i.e., when the groundwater level rises to +950, the stability of the end wall reaches the critical stability state. With the passage of time, the creep of the sliding surface accelerates until the entire end wall landslide.

Inclinometer and Improved SBAS Methods with a Random Forest for Monitoring Landslides and Anchor Degradation in Otoyo Town, Japan

Kochi Prefecture is located in an active zone of Japan that is frequently subjected to landslides due to heavy precipitation in typhoon seasons. Slow-moving landslides have been reported by both the local prefectural authorities and the National Government of Japan. We observed landslide movements in Otoyo Town by using ground- and satellite-based tools. Despite the high cost of establishing a borehole inclinometer survey to obtain accurate ground-based measurements, no previous InSAR study has been conducted in Otoyo Town, and the capacity for regional discrimination between active and inactive slow-moving landslides when using these tools remains unclear. We found that the horizontal velocity component was dominant at a rate of 21.4 mm/year across the whole of Otoyo Town. Satellite-based monitoring of ground-anchor efficiency may be possible in combination with ground-based inclinometer surveys. Three types of land cover are present in the study area—urban, field, and forests—and we selected a random forest (RF) model to extract low-coherence pixels by using optical and radar satellite sensors to identify important features and precisely remove pixels causing decorrelation. Long-term monitoring results from ground-based surveys, including inclinometer (boreholes) and anchor tension distribution data, were compared with the results of synthetic radar by using coherence-based small baseline subset (CB-SBAS) measurements. Generally, landslide occurrence was investigated across the whole of Otoyo Town, and we specifically evaluated the reliability of InSAR measurements in the Kawai landslide as a study site scale. The activity of the Kawai landslide channel was evaluated with borehole inclinometer displacement measurements (15.46 mm) and an anchor pressure survey (736 kN) from 2016 to 2019, as well as the steady state of the area (1.7 mm for the borehole inclinometer and 175 kN for the anchor pressure measurements), although a high cumulative precipitation of 3520 mm was reached during 2020 due to the ground anchor efficiency, which showed a consistent tendency with respect to the InSAR displacement measurements (14 mm during 2018 and 2019 and 0.7 mm during 2020). This comparison showed a consistent time-series displacement correlation, which was strengthened after introducing the RF mask into the analysis procedure, as the RF model correction reduced the standard deviation from the line-of-sight (LoS) average velocity estimation by 1.9 mm/year. Our research will help mitigate landslide impacts in Otoyo Town and its surroundings.

Anatomical growth response of Fagus sylvatica L. to landslide movements

Determining the age of landslide events is crucial for determining landslide risk, triggers, and also for predicting future landslide occurrence. Currently, the most accurate method for dating historical landslide events is dendrogeomorphic analysis. Unfortunately, the standard use of macroscopic growth responses of damaged trees for dating landslide activity suffers from many shortcomings. Thus, the aim of this study is to analyze in detail the growth response of trees to landslide movements at the anatomical level, a completely groundbreaking methodological approach. Ten specimens of European beech (Fagus sylvatica L.) were analyzed at two sampling heights, growing in two morphologically contrasting zones of the landslide area. Detailed anatomical analysis was focused on changes in morphometric parameters of the vessels and in the number of radial rays. The period (2008–2012) with the occurrence of the largest landslide movement (2010) recorded by long-term monitoring was analyzed. The results obtained revealed different anatomical responses in trees growing in different morphological zones of landslide. The tree responses on the ridge corresponded to the manifestations of tension wood formation, which corresponded to the stem tilting due to the landslide block movement. In the case of the trees in the trenches, root damage due to the subsidence of the landslide block blocked the flux of phytohormones, and their accumulation caused a significant reduction in the parameters of vessels and an increase in the number of rays. The study also includes recommendations in the future application of anatomical analyses in landslide research resulting from the obtained results. Thus, the obtained findings will improve the acquisition of chronological data for the purpose of landslide risk assessment.

The spatial relationship between landslide and land use activities in Langat River Basin: A case study

Landslide is a natural hazard that occurs all over the world and can cause enormous damage to the environment and human life. The developing countries are not spared from dealing with the issue of landslides where land use activities are recognised as one of the most triggering factors of landslide occurrences. In this study, investigation on spatial relationship was performed between landslide occurrences and land use activities at Langat River Basin. Landslide spatial distribution was determined using land use activities for the year 2021. The land use map was generated using supervised classification by Artificial Neural Network (ANN) approach. In addition, the accuracy assessment was applied using Kappa coefficient to validate the land use classification. A total of 70 historical landslide points was used to analyse the spatial relationship between landslide and land use activities. Based on the results, land use category at Langat River Basin was dominated by agriculture with 59.65%. The overall accuracy for land use classification was 90.81% and kappa coefficient was 0.88. Meanwhile, the spatial relationship between landslide occurrence and land use activities was higher in the built-up area with 48.57%. The growing population and economic sector in Langat River Basin were found to be contributing to the increase in built-up areas. Thus, these results are particularly useful in understanding the spatial relationship between landslide occurrence and land use activities where the development area is more vulnerable to facing landslide disasters. These findings will also help the government to achieve the agenda for Sustainable Development Goal (SDG) 2030 as highlighted to mitigate the risk of natural disasters.

Increasing landslide activity in the Taxkorgan River Basin (eastern Pamirs Plateau, China) driven by climate change

Global warming promotes glacier retreat, snow melting, and permafrost thawing, thereby increasing landslide activity in alpine mountain regions. However, our understanding of the effects of climate change on landslides is restricted by the sparse nature of landslide records. In this study, taking the Taxkorgan River basin in the eastern Pamirs as the study area, we assessed the interaction between landslides and climate change over the past 20 years using a reconstructed landslide inventory and a set of downscaled meteorological data, and we projected the future impacts of climate change on landslide activity. From 2000 to 2019, the number of landslides increased exponentially under global warming. Especially in 2000 and 2014, the abrupt increases in temperature and precipitation caused a more significant increase in the number of landslides. Ninety-four percent of the landslides occurred in the warm season (April to October), which is attributed to the diminishing snow cover in the warm season and the increase in the annual snow cover variation. Spatially, the increase in the number of landslides with elevation was due to the increase in the rate of temperature rise, suggesting that the high-elevation region (4500 m above sea level) responds more significantly to climate change and is more susceptible to landslides. The future climate is predicted to exhibit a warming and wetting trend, which will likely induce more frequent landslides for some time. We suggest that in alpine mountain areas, there is an urgent need to improve the comprehensive ground observation network and reveal the underlying relationship between the variable climate and landslides using multiple datasets, which would contribute to the accurate assessment of the risks posed by landslides induced by climate change and the adequate management of this risk under the warming climate in the future.

Landslide monitoring techniques in the Geological Surveys of Europe

Landslide monitoring is a mandatory step in landslide risk assessment. It requires collecting data on landslide conditions (e.g., areal extent, landslide kinematics, surface topography, hydrogeometeorological parameters, and failure surfaces) from different time periods and at different scales, from site-specific to local, regional, and national, to assess landslide activity. In this analysis, we collected information on landslide monitoring techniques from 17 members of the Earth Observation and Geohazards Expert Group (from EuroGeoSurveys) deployed between 2005 and 2021. We examined the types of the 75 recorded landslides, the landslide techniques, spatial resolution, temporal resolution, status of the technique (operational, non-operational), time of using (before the event, during the event, after the event), and the applicability of the technique in early warning systems. The research does not indicate the accuracy of each technique but, rather, the extent to which Geological Surveys conduct landslide monitoring and the predominant techniques used. Among the types of landslides, earth slides predominate and are mostly monitored by geological and engineering geological mapping. The results showed that Geological Surveys mostly utilized more traditional monitoring techniques since they have a broad mandate to collect geological data. In addition, this paper provides new insights into the role of the Geological Surveys on landslide monitoring in Europe and contributes to landslide risk reduction initiatives and commitments (e.g., the Kyoto Landslide Commitment 2020).

InSAR-Based Active Landslide Detection and Characterization Along the Upper Reaches of the Yellow River

Landslides have attracted extensive attention and research worldwide because of their tremendous destructiveness, and many catastrophic landslides have occurred along river corridors and reservoir bank slopes. The detection and detailed monitoring of potential landslides are prerequisites for landslide disaster prevention, with recent advance in spaceborne Interferometric Synthetic Aperture Radar (InSAR) having effectively addressed this challenge. In this study, a wide-area landslide detection and monitoring framework, combining multiple InSAR techniques, is proposed to investigate active landslides along the upper reaches of the Yellow River from Longyang Gorge to Liujia Gorge (UYRLL), north-west China. A total of 597 active landslides have been mapped in this region for the first time. Our analyses suggest that a large percentage of the detected landslides are distributed at an elevation of 2,000-3,000 m with slope angles of 5-30°and their spatial distribution density is correlated with regional tectonic activity. Multi-Temporal InSAR (MTI) techniques have also been adopted to analyze the surface motion characteristics of two typical landslides (i.e., the Lijia landslide and the Xijitan landslide), showing that these two landslides are dominated by linear motion. The landslide movements also contain slight non-linear oscillations, inferred from wavelet analysis to be associated with reservoir water area changes and seasonal rainfall. The proposed framework herein can be extended to the detection and monitoring of active landslides in other areas with similar geomorphic features, and the above findings on landslide characteristics can also contribute to landslide prevention and mitigation in the upper Yellow River area.

Оползневые и обвально-осыпные процессы на автомобильных дорогах Республики Ингушетия

Introduction. A significant impact on the geological environment of the Republic of Ingushetia and the development of dangerous slope processes is exerted by the construction, reconstruction and operation of highways, which make significant changes to the natural environment of mountain slopes. The article provides an assessment of the degree of activity and danger of landslide and landslide-talus processes on the highways of the republic for 2005–2022. Materials and research methods. The key method used in this work was the analysis of various materials containing information on the activity of the manifestation of landslide and avalanche-talus processes on the highways of the Republic of Ingushetia. The main sources used were literary sources, reports and published data of the Center for State Monitoring of the State of the Subsoil (GMSN) of the Federal State Budgetary Institution «Hydrospetsgeology» for 2005–2022. Research results and their discussion. The authors characterized the conditions and causes, as well as assessed the activity and danger of landslide and landslide-talus manifestations on the highways of the Republic of Ingushetia for 2005–2022. The paper provides information on the extent of the destruction and deformation of the roadway. Conclusions. The analysis of the activity of landslide manifestations on the roads of the Republic of Ingushetia over the past 18 years has shown that the greatest extent of landslide activity was observed in 2010, 2016 and 2017, and a very weak degree of activity was observed in 2008. The maximum landslide activity on the roads of the republic was observed in 2005 and 2013, and the minimum – in 2019. According to the results of the study, the sections of the republic’s highways that are most susceptible to landslide and landslide-talus processes have been identified. The performed analysis indicates the predominant development of landslide manifestations on the roads of the Malgobek administrative district, and landslide-talus – on the roads of the Jeyrakh district.

Preliminary determination of wood stocks for evaluation of carbon storage in forest systems of landslide slopes

The main purpose of the study is to determine the dynamics of wood volumes in tree populations by forest communities of landslide elements for further assessment of carbon sequestration and to identify the possibility of population-based methods for indicating landslide activity. The studies were carried out in 2008-2019 at specially protected natural reservation “Massiv-Dachny” on the right bank slopes of the Volga River (Tatarstan, Russia). As a result of the research, it was revealed that a distinctive feature of slope forests under conditions of landslide-scree processes is a decrease in the proportion, forest stand and crown density of native forest-forming species – Q. robur, P. sylvestris, and an increase in the proportion of A. platonoides, B. pendula, P. tremula with lower depositing capacity. Under conditions of temporary stability of landslide elements, the formation of long-term derivative T. cordata forests occurs. Clear cuttings of old-growth primary oak forests with pine carried out in 2018-2019 rise the risks of new landslide displacements and led to imbalance in the composition and structure of slope phytocenoses. For the first time for the study area, a database of morphometric and population parameters of trees in phytocenoses of landslide slopes was formed.

Debris-flow activity and sediment dynamics in the landslide-influenced Lattenbach catchment, Austria

Deep seated landslides are common phenomena in Alpine areas. In case of a direct connectivity with the channel system, the catchment’s sediment yield and the probability of other forms of mass wasting processes such as debris flows may be increased significantly. Up to now, sediment dynamics related to deep-seated landslides and debris flows have not been quantified. The Lattenbach catchment (basin area 5,3 km², relief 2134 m) in Grins (Tyrol, Austria), is an example for an active DF-site, where there is geomorphological evidence of deep-seated landslide activity. In this study we shed light (1) on the location and size of active landslides in the catchment, that may deliver sediment to the channel system. Furthermore, we want to (2) quantify the contributed sediment volumes by these landslides (3) and estimate the exported sediment by debris flow. We apply an image correlation algorithm to high resolution ALS and TLS terrain models of derived over a period of 14 years to calculate surface movement rates within the catchment and locate deep seated landslide activity. We further assess the sediment yield of these landslides to the channel system and relate that with DF-volumes measured by a monitoring station at the catchment outlet. We find that there are five deep-seated landslide bodies directly connected to the channel system in the catchment. These are the largest source of sediment and significantly increases the overall sediment yield of the catchment. Our study shall contribute to the limited knowledge about the importance of deep-seated landslides for sediment dynamics and debris-flow activity, as their presence is predicted to be more frequent in the wake of global warming.

МОНІТОРИНГ ВЕРТИКАЛЬНИХ ЗМІЩЕНЬ ЗЕМНОЇ ПОВЕРХНІ ПРАВОБЕРЕЖЖЯ КАНІВСЬКОГО ВОДОСХОВИЩА

Monitoring of vertical displacements of the earth's surface on the right bank of the Kaniv Reservoir in the Vytatchiv-Stajky region was carried out using the differential radar interferometry (DinSAR) technique. According to the results of observations during the spring period from 2015 to 2023, active landslide areas are displayed. The DinSAR method is briefly described, emphasising data filtering steps for landslide activation mapping. A high data correlation was recorded, and the presence of zones of active shifts on the shore of the reservoir was confirmed. The spread and intensity of landslide manifestations are determined by the peculiarities of the geological and geomorphological structure of the territory, its tectonic, neotectonic and seismic regimes, and hydrological and climatic conditions. Limitations of the method arising from the temporal decorrelation of the radar signal in regions with a large amount of vegetation are determined. Due to the significant decorrelation between the obtained results of forested and watered areas, the DinSAR technique, a digital elevation model (DEM), analysis of base surface maps and the results of spectral index calculations were combined to identify regions of active landslides caused by waterlogging of the Dnieper slopes. The study demonstrates the feasibility of using DinSAR to detect and monitor surface deformation.

Characteristics of landslides induced by an earthquake from a hidden strike-slip active fault in the Cianjur Area of West Java

On November 21, 2022, the Cianjur area in West Java, Indonesia, experienced devastating landslides caused by a magnitude 5.6 earthquake, with the epicenter traced to a hidden active fault approximately 11 kilometers beneath the surface, known as the Cugenang Fault. This study investigates the post-disaster landslides and aims to discover the characteristics of the landslides triggered by this earthquake. The methodology involves literature review, lithology descriptions, landslide slip surface analysis, soil analysis, slope assessment, land cover and land use change examination, landslide orientation evaluation, and distance measurements to the earthquake's epicenter and the Cugenang fault. Drones aided spatial landslide analysis. The study highlights the strong link between intense shaking along the active fault and landslide occurrences. Due to lithological bedding control, these landslides all head southwest and are located 0.35 to 0.67 kilometres from the fault. The residual soil, highly weathered breccia, and possible tuff volcanic deposits, which act as a sliding plane, lie in a similar direction to the slope, creating a vulnerable setting for landslides. The morphology and exposures of the Sarampad and Rawacina landslides showed similar phenomena to liquefaction. Land use changes, including slope cutting without proper stabilization measures, contribute to landslides to a certain degree.

Microseismic Event Classification With Time-, Frequency-, and Wavelet-Domain Convolutional Neural Networks

Passive seismics help us understand subsurface processes, e.g. landslides, mining, geothermal systems etc. and help predict and mitigate their effects. Continuous monitoring results in long seismic records that may contain various sources, which need to be classified. Manual detection and labeling of recorded seismic events is not only time consuming but can also be inconsistent when done manually, even in the case where it is done by the same expert. Therefore, an automated approach for classification of continuous microseismic recordings based on a Convolutional Neural Network (CNN) is proposed, with a multiclassifier architecture that classifies earthquakes, rockfalls and low signal to noise ratio quakes. Furthermore, we propose three CNN architectures that take as input time series data, Short Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) maps. The suitability of these three networks is rigorously assessed over five months of continuous seismometer recordings from the active Super-Sauze landslide in France. We observe that all three architectures have excellent and very similar performance. Furthermore, we evaluate transferability to a geographically distinct seismically active site in Larissa, Greece. We demonstrate that the proposed network is able to detect all 86 catalogued earthquake events, having only been trained on the Super-Sauze dataset and shows good agreement with manually detected events. This is promising as it could replace painstaking manual labelling of events in large recordings.

THE IMPACT OF GEOLOGICAL AND RAINFALL CHARACTERISTICS ON SLOPE STABILITY ANALYSIS IN SHALLOW LANDSLIDE MODELLING USING THE TRIGRS MODEL

West Java Province has a high potential for susceptibility to landslides. West Bandung Regency is one of the regions in West Java which has high occurrences of landslides triggered by rainfalls. Rainfall-induced landslides in this region have occurred 165 times during rainfall in the last ten (10) years. An effort to predict the landslide occurrences in this region requires the knowledge of factors affecting the hillslope stability. This paper aims to (1) evaluate the parameters affecting slope stability, (2) determine rainfall characteristics affecting slope, and (3) evaluate the performance of TRIGRS modelling. This study applies a deterministic method using the model of TRIGRS to analyze the effect of one-day antecedent rainfall intensity on the instability of hillslopes. The parameters used in this study are based on field investigation, geological and topographical maps, soil engineering properties, and historical rainfall data. The effect of one-day antecedent rainfall intensity was considered in two scenarios, i.e. 6 hours and 12 hours of antecedent rainfall. Modelling results show that hillslope instability in the study areas is affected by many factors, such as hilly morphology, steep slopes, low shear strength parameters, weathering of volcanic rocks, and the lineament density of geological structures. The modelling simulation also indicates that landslide occurrences in this study area are initiated by a long antecedent rainfall period. Based on ROC analysis, the TRIGRS model shows that the model performance evaluation is in good agreement for modelling slope stability against actual landslide events.

LANDSLIDE PROTECTION STRUCTURE IN THE FORM OF COUNTERFORTS MADE OF BORED PILES

At present, we are witnessing an intensive urbanization which is also typical for most regions of Ukraine. As consequence, there is an increase in the anthropogenic pressure on certain territories that’s why the problem of the development of such phenomena as landslides has become particularly relevant. The landslides are one of the most common exogenous geological processes creating environmental and technogenic hazards. The reasons for their activation can be divided into natural and man-made. The landslide processes of natural origin arise, as a rule, on the coast, on the slopes of river valleys and in the network of gullies and ravines. The technogenic landslides are observed in the construction sector, reconstruction and operation of buildings and structures built on a plot of slopes with difficult engineering and geological conditions. With the aim of preventing the occurrence of landslides and related emergencies of a man-made and natural nature, it is necessary to implement economically and environmentally sound anti-landslide measures before the start of economic development of landslide and landslide hazard areas. In building on landslide and landslide hazard slopes or on artificial slopes, it is necessary to keep large masses of soil in stable state. The occurrence and activation of landslides leads to the formation of unacceptable deformations, disruption of the slope stability as well as the destruction of buildings and structures. The deformations of buildings and structures located on or near slopes occur from landslide processes that cannot be stopped by regular landslide prevention works. In these cases, retaining anti-landslide structures made of bored and cast-in-place piles embedding in stable bedrocks and combined with reinforced concrete grille are used to protect against the formation of landslides. Such structures are one of the most optimal, technological and cost-effective methods for stabilizing landslide dislocations. The choice of the anti-landslide retaining structures type and their location on the slope depends on the value of the shear stress and its distribution along the slope, the power of the shear rock mass, the configuration of the slope, the state of shear at the time of building and other factors. In this work, the main existing structures of transverse and longitudinal retaining pile-type anti-landslide structures, their advantages and disadvantages, conditions of application were analyzed. As a result of this, a new design retaining anti-landslide structure with increased loadability and reduced consumption of materials has been proposed. The landslide protection structure is made in the form of the counterforts run parallel to the length of the shear slope formed of round bored piles, whose diameter increases in the direction of shear displacement. While, the piles are laid with their lower ends in firm grounds and combined from above with reinforced concrete grille of variable height with an inclination of the bottom surface towards base of slope. This structure is designed to stabilize landslide hazard and landslide slopes as well as to increase stability of the slopes plots on which buildings and structures for various purposes are operated, reconstructed and built.

Prediction analysis of landslide displacement trajectory based on the gradient descent method with multisource remote sensing observations

Landslides can result in extensive casualties and huge economic losses. The accurate discrimination of the main slip direction and deformation trajectory is an important prerequisite for studying landslide formation mechanisms and designing landslide control schemes. In the process of landslide evolution over time, the main slip direction also changes dynamically and provides a comprehensive reflection of the landslide displacement state. However, few studies on this topic have been published. In this paper, a new methodology for analyzing slope stability is proposed based on three techniques: interferometric synthetic aperture radar (InSAR), unmanned aerial vehicle (UAV), and ground-based interferometric synthetic aperture radar (GB-InSAR). The Small Baseline Subset Interferometric SAR (SBAS-InSAR) technique is combined with an overall analysis of the study area to identify the regions of interest (ROIs) with large deformation and the starting target points, and the fusion results of radar deformation data (RDD) and digital surface model (DSM) data are used to fit the deformation surface field of the ROIs. The gradient descent approach is executed to obtain the running trajectory points of the target masses so that the main slip direction and displacement trajectory in the study area can be predicted at small scales. The measured data for the Hongshiyan landslide in Yunnan Province are used to verify the effectiveness of the method, and the predicted results are consistent with the actual landslide direction. The experimental results show that the method can exactly identify the deformation area, especially in the case of a fast-changing deformation trend. This approach can provide more accurate monitoring area results to support the rapid control and prevention of landslide hazards by analyzing the minimum pixel grid (i.e. points), as the smallest spatial unit at a time interval of minutes. The study shows that the method can efficiently combine space–Earth multisource monitoring data to clarify the main slide direction and improve the postslide trajectory prediction of the slope, which is beneficial for assessing disaster risks and improving landslide prevention and control effects, reflecting the engineering application value of the approach.

Extreme rainfall-related accelerations in landslides in Danba County, Sichuan Province, as detected by InSAR

Landslides are frequent mountainous geohazards induced by multiple factors, such as extreme rainfall, river erosion, and intense anthropogenic activities. On 17 June 2020, a rainstorm hit Danba County, Sichuan Province, and triggered the catastrophic Aniangzhai landslide. The impact of this rainstorm on landslide kinematics in this region has seldom been investigated. We used a time-series interferometric synthetic aperture radar (InSAR) analysis to map the active slopes in Danba County using one ascending (2015–2021) and one descending (2018–2021) Sentinel-1 dataset. A total of 36 landslides (63.1 km2) were detected along riverbanks. The time series of eastward and vertical displacements during 2018–2021 were retrieved by integrating the ascending and descending Sentinel-1 datasets. The maximum eastward and vertical displacement rates obtained are 229 and −75 mm/yr, respectively. Seasonal accelerations are correlated with concentrated rainfall. We suggest that the 2020 rainstorm and the abundant precipitation during the water year 2020 altered the long-term displacement trends of active landslides. We further constrained the volumes of the Niela and Gaoding landslides in the order 3.6–6.9 × 107 m3 and 5.4–6.0 × 108 m3, respectively, using 2D displacement rates and mass conservation equations. Our results demonstrate that multi-temporal and multi-orbit InSAR measurements can provide insights into the evolution and mechanism of landslides.