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Prediction of ground displacements and velocities from groundwater level changes at the Vallcebre landslide (Eastern Pyrenees, Spain)
Abstract
In active landslides, the prediction of acceleration of movement is a crucial issue for the design and performance of warning systems. The landslide of Vallcebre in the Eastern Pyreenes, Spain, has been monitored since 1996 and data on rainfall, groundwater levels and ground displacements are measured on a regular basis. Displacements observed in borehole wire extensometers have shown an immediate response of the landslide to rainfall episodes. This rapid response is likely due to the presence of preferential drainage ways. The occurrence of nearly constant rates of displacement in coincidence with steady groundwater levels suggests the presence of viscous forces developed during the movement. An attempt to predict both landslide displacements and velocities was performed at Vallcebre by solving the momentum equation in which a viscous term (Bingham and power law) was added. Results show that, using similar rheological parameters for the entire landslide, computed displacements reproduce quite accurately the displacements observed at three selected wire extensometers. These results indicate that prediction of displacements from groundwater level changes is feasible.
... The movement comprises an area of 0.8 km 2 (about 600 m wide and 1200 m long), with observable ground displacements and cracking. The landslides have been active for at least several centuries, and their exact age is uncertain [21]. ...
... Geologically, the mobilized sediments are composed of a series of claystone, shale and gypsum layers sliding above a thick limestone substrate, which are all from the Upper Cretaceous to the Lower Paleocene period [21,22]. Inverse faults and several associated folds have an effect on the materials. ...
... This is interpreted as the Lower Units moving faster than the Upper Units, which has been verified by the implemented network of monitoring sensors. The landslide's average slope is approximately 10 • [21], and the underlying shearing surface depth reaches 42 m in the Middle Unit and 15 m in the Lower Unit, according to core drill holes ( Figure 2), with most of the sliding surface being rather flat [22]. The Lower Unit is the most active section, with the Vallcebre water stream regularly eroding its toe, generating local rotational faults that reduce overall stability. ...
Geophysical surveys are a noninvasive reliable tool to improve geological models without requiring extensive in situ borehole campaigns. The usage of seismic refraction tomography (SRT), electrical resistivity tomography (ERT) and borehole data for calibrating is very appropriate to define landslide body geometries; however, it is still only used occasionally. We present here the case of a Spanish Pyrenees slow-moving landslide, where ERT, SRT and lithological log data were integrated to obtain a geological three-dimensional model. The high contrasts of P-wave velocity and electrical resistivity values of the upper materials (colluvial debris and clayey siltstone) provided accurate information on the geometry of the materials involved in the landslide body, as well as the sliding surface. Geophysical prospecting allowed us to identify the critical sliding surface over a large area and at a reduced cost and, therefore, gives the geophysical method an advantage over borehole data. The three-dimensional model was used to carry out stability analyses of a landslide in 2D and 3D, which, coherently with previous studies, reveal that the lower part is more unstable than the upper units.
... This broad category generally includes landslides that move from millimeters to meters per year (Hungr et al., 2014), although some classifications include landslides that move up to 100 m/year (Lacroix et al., 2020). They tend to be deep-seated (>3 m thick; LaCroix et al., 2020) and move persistently or seasonally on the timescale of years to decades (e.g., Chambers et al., 2011;Corominas et al., 2005;Handwerger et al., 2013;Iverson & Major, 1987;Malet et al., 2002;Schulz et al., 2018;Schulz, McKenna, et al., 2009). Slow-moving landslides occur globally in regions with mechanically weak, clay-rich rocks or soil (Keefer & Johnson, 1983;Lacroix et al., 2020) and typically gentle slopes <20° (Lacroix et al., 2020). ...
... Documented sources of stress perturbations include earthquakes (e.g., Lacroix et al., 2015), undrained loading (e.g., Booth et al., 2018), and atmospheric pressure variations (e.g., Schulz, Kean, et al., 2009). By far the most common driver of movement is groundwater pressure fluctuations resulting from infiltrating precipitation (e.g., Corominas et al., 2005;Iverson & Major, 1987;Malet et al., 2002). For this class of landslides, infiltrating rainfall or snowmelt events increase pore-water pressure and consequently reduce the effective normal stresses, thereby reducing Coulomb friction (Iverson, 2000;Terzaghi, 1943). ...
... We see a distinct pore pressure threshold in this relationship that must be reached for motion to begin and an apparent cap on the system setting a maximum pore pressure that can be achieved. Similar tight and nonlinear coupling between piezometric records and landslide displacement has been observed at slow-moving landslides in Spain and France (Corominas et al., 2005;Malet et al., 2002). At Oak Ridge earthflow, the fastest and slowest recorded velocities correspond with only a 10 kPa pressure difference. ...
The rate and timing of hydrologically forced landslides is a complex function of precipitation patterns, material properties, topography, and groundwater hydrology. In the simplest form, however, slopes fail when subsurface pore pressure grows large enough to exceed the Mohr‐Coulomb failure criterion. The capacity for pore pressure rise in a landslide is determined in part by the thickness of the unsaturated zone above the water table, which itself is set by weathering patterns that should have predictable patterns across different lithologies. To investigate how this structure affects landslide behavior, we exploit a multi‐year record of precipitation, pore pressure, and velocity from Oak Ridge earthflow, a slow‐moving landslide set in Franciscan mélange, northern California, USA. In conjunction with electrical resistivity tomography and hydraulic conductivity measurements, these data show that Oak Ridge has a thin weathered profile that is comparable in thickness to other mélange landslides in California. We propose that due to the inherently thin vadose zone, mélange landscapes experience an unusually high water table that frequently brings them close to movement; however, the capacity to increase stress is limited by the small amount of dynamic storage available. Instead, excess pore pressure is shed via springs and saturation overland flow once the water table reaches the surface. Linkages between weathering patterns, hydrology, and deformation can explain behavior patterns exhibited by Franciscan mélange earthflows across a large precipitation gradient.
... The combination of the optimum thresholds from two landslide predictor variables in two dimensions (2D) as X-Y pairs is referred to as a bilinear threshold model, first proposed by Mirus et al. (2018a). Some landslide studies discussed different effects that groundwater systems may have on landslide initiation (Bronnimann, 2011;Cascini et al., 2010;Corominas et al., 2005;Duan et al., 2019;Hong and Wan, 2011;Trigo et al., 2005;Zhao et al., 2016). However, the asset that regional groundwater level information may have in predicting landslide initiation on a regional scale is still underexplored. ...
... This is to say that in regions with very slow groundwater responding systems where rainfall-induced shallow landslides prevail, precipitation-based thresholds can still practically be useful for landslide prediction and warning. However, the need for hydrological thresholds is true for both shallow-and deep-seated landslides (Cascini et al., 2010;Corominas et al., 2005;Duan et al., 2019;Hong and Wan, 2011), which are thus more powerful than precipitation-based thresholds. More studies also confirm the high warning capability of hydro-meteorological thresholds over precipitation-based thresholds after incorporation of either soil moisture or catchment storage (Ciavolella et al., 2016;Mirus et al., 2018a;Prenner et al., 2018;Thomas et al., 2019;Wicki et al., 2020). ...
... Therefore, the groundwater level was considered as a proxy and used as a hydrological landslide predictor variable in our research. The component of groundwater has been on the one hand considered as a landslide triggering factor and on the other hand as a landslide predisposing factor (Cascini et al., 2010;Corominas et al., 2005;Duan et al., 2019;Hong and Wan, 2011). Being a hydrological parameter, it was subjectively considered as a landslide predisposing factor and plotted on the x axis of a 2D plot as a cause in a cause-trigger framework. ...
The incorporation of specific regional hydrological characteristics in empirical statistical landslide threshold models has considerable potential to improve the quality of landslide predictions towards reliable early warning systems. The objective of this research was to test the value of regional groundwater level information, as a proxy for water storage fluctuations, to improve regional landslide predictions with empirical models based on the concept of threshold levels. Specifically, we investigated (i) the use of a data-driven time series approach to model the regional groundwater levels based on short duration monitoring observations and (ii) the predictive power of single variable and bilinear threshold landslide prediction models derived from groundwater levels and precipitation. Based on statistical measures of the model fit (R2 and RMSE), the groundwater level dynamics estimated by the transfer function noise time series model are broadly consistent with the observed groundwater levels. The single variable threshold models derived from groundwater levels exhibited the highest landslide prediction power with 82 %–93 % of true positive alarms despite the quite high rate of false alarms with about 26 %–38 %. The further combination as bilinear threshold models reduced the rate of false alarms by about 18 %–28 % at the expense of reduced true alarms by about 9 %–29 % and is thus less advantageous than single variable threshold models. In contrast to precipitation-based thresholds, relying on threshold models exclusively defined using hydrological variables such as groundwater can lead to improved landslide predictions due to their implicit consideration of long-term antecedent conditions until the day of landslide occurrence.
... The movement comprises an area of 0.8 km 2 (about 600 m wide and 1200 m long), with observable ground displacements and cracking. The landslides have been active for at least several centuries, and their exact age is uncertain [21]. ...
... Geologically, the mobilized sediments are composed of a series of claystone, shale and gypsum layers sliding above a thick limestone substrate, which are all from the Upper Cretaceous to the Lower Paleocene period [21,22]. Inverse faults and several associated folds have an effect on the materials. ...
... This is interpreted as the Lower Units moving faster than the Upper Units, which has been verified by the implemented network of monitoring sensors. The landslide's average slope is approximately 10 • [21], and the underlying shearing surface depth reaches 42 m in the Middle Unit and 15 m in the Lower Unit, according to core drill holes ( Figure 2), with most of the sliding surface being rather flat [22]. The Lower Unit is the most active section, with the Vallcebre water stream regularly eroding its toe, generating local rotational faults that reduce overall stability. ...
... We evaluate the ground stability of the Ravine de l'Eglise during Cyclone Hyacinthe using a deterministic model based on limit equilibrium equations [41]. This simple 2D analysis can help assess the influence of the increase in groundwater on slope stability and verify the shape and depth of the slip surface [42][43][44][45]. ...
... Alteration of the material forms thin layers of grey clays in some areas ( Figure S1). The Intermediate Unit is intensively deformed, in particular due to the movement induced by the slow-moving Grand Ilet landslide, and sensitive to erosion on its steep slopes (>20 • ) (i.e., badlands) [8,43,47]. The Intermediate Unit holds the Grand Ilet aquifer, which has high conductivity and porosity [50]. ...
... Pursuing the next simulations in this way, with a piezometric level similar to that simulated for the first ten days of Cyclone Hyacinthe, we observe a succession of more or less large retrogressive destabilizations of the slope. The last scenario corresponds to the saturation of almost all of the intermediate unit, as has occurred during the last days of the Cyclone Hyacinthe rainstorm (scenario t 6 ) [8,[42][43][44][45]. For this scenario, we observe that the remaining slope is unstable (FoS << 1) and causes a failure that reaches the current gully head. ...
In January 1980, during exceptional cyclonic rainfall, an atypical landslide, called déboulé, rapidly generated the permanent 700 m-long gully of the Ravine de l’Eglise on an inhabited plateau in Reunion Island (Indian Ocean). Retrieving the initial conditions that led to this historical process is both challenging and necessary for understanding the mechanism of gully incision and providing pointers for improving risk mitigation in relation to this phenomenon. In this study, we reconstruct the pre- and post-failure topographies using SFM (structure from motion) applied on archive aerial photographs. Based on the comparison of these digital elevation models, we estimate the volume of material eroded to be ca. 0.63 Mm3. Groundwater level increase, part of the triggering mechanism, is hindcast in the catchment of the gully using a lumped hydrological model. This model shows that in only a fortnight the groundwater level probably rose by 36 m, which could have caused a progressive increase in pore pressure and triggered formation of the gully by retrogressive landslides. We test this hypothesis by considering the pre-failure topography and the hindcast groundwater level in a deterministic model based on limit equilibrium equations to explore ground stability. The evolution of ground stability with a rise in the water table shows that the gully may have extended in a headward direction by retrogressive landslides. This is the first quantitative reconstruction of an exceptional historical event affecting the territory of Reunion Island. The methods used to investigate the Ravine de L’Eglise incision thus offer new
complementary insights and challenges for understanding the mechanism and the temporality of gully formation.
... However, due to the presence of the wall, the retrogressive failure mechanism discussed above cannot help in the interpretation of the (Corominas et al., 2005(Corominas et al., ). 1984 landslide. ...
... The Vallcebre landslide (Fig. 5) is an example of slow active movement in siltstones and shales (Corominas et al., 2005). Thanks to an accurate long-lasting monitoring, a rich set of data is available about the pore pressure regime and the kinematics of the landslide. ...
... The Vallcebre landslide (the figure indicates couples of piezometers installed at the same site) (fromCorominas et al., 2005). ...
A set of materials covering a wide class comprised between soils and fractured rocks displays a variable and complex hydraulic/mechanical response to external inputs that make quite complicated both the measurement of properties and the modeling of material behaviour. In fact, weak interparticle bonding and a network of irregular and often interconnected discontinuities can strongly and unevenly affect permeability, stiffness and shear strength, making difficult the interpretation of natural events, such as landslides, and uncertain the analysis and design of engineered slopes and of man-made works.
This paper reports some examples taken from the Authors' experience and from the literature, which illustrate the difficulty to correctly understand or analyze the behaviour of such complex materials through the classical approaches of Soil or of Rock Mechanics, highlighting at the same time the complex role that discontinuities play in groundwater flow and pore water pressure regime.
... The combination of the optimum thresholds from two landslide predictor 90 variables in two dimensions 2D as X-Y pairs is referred to as a bilinear threshold models firstly proposed by Mirus et al., (2018a). Some landslide studies discussed different effects that groundwater system may have on landslide initiation (Bronnimann, 2011;Cascini et al., 2010;Corominas et al., 2005;Duan et al., 2019;Hong and Wan, 2011;Trigo et al., 2005;Zhao et al., 2016). However, the asset that regional groundwater level information may have in predicting landslide initiation on a regional scale is still underexplored. ...
... In regions with very slow groundwater responding system where rainfall-induced shallow landslides prevails, precipitation based thresholds can still practically be useful for landslide prediction and warning. However, the need for hydr ological thresholds is true for both shallow and deep seated landslides (Cascini et al., 2010;Corominas et al., 2005;Duan et al., 2019;445 Hong and Wan, 2011) and thus, being more powerful than precipitation based thresholds. More studies also confirm the high warning capability of hydro-meteorological thresholds over precipitation based thresholds after incorporation of either soil moisture or catchment storage (Ciavolella et al., 2016;Mirus et al., 2018a;Thomas et al., 2019;Wicki et al., 2020). ...
... Therefore the groundwater level was considered as a proxy and used as a hydrological landslide predictor variable in our 455 research. The component of groundwater has been on one hand considered as landslide triggering factor and on the other hand as landslide predisposing factor (Cascini et al., 2010;Corominas et al., 2005;Duan et al., 2019;Hong and Wan, 2011) . Being a hydrological parameter, it was subjectively considered as landslide predisposing factor and plotted on x-axis of a 2D plot as a cause in a cause-trigger framework. ...
Incorporation of specific regional hydrological characteristics in empirical statistical landslide threshold models has considerable potential to improve the quality of landslide predictions towards reliable early warning systems. The objective of this research was to test the value of regional groundwater level information, as a proxy for water storage fluctuations, to improve regional landslide predictions with empirical models based on the concept of threshold levels. Specifically, we investigated: i) the use of a data driven time series approach to model the regional groundwater levels based on short duration monitoring observations; ii) the predictive power of single variable and bilinear threshold landslide prediction models derived from groundwater levels and precipitation. Based on statistical measures of the model fit (R2 and RMSE), the groundwater level dynamics estimated by the transfer function noise time series model are broadly consistent with the observed groundwater levels. The single variable threshold models derived from groundwater levels exhibited the highest landslide prediction power with 82–93 % of true positive alarms despite the quite high rate of false alarms with about 26–38 %. Further combination as bilinear threshold models reduced the rate of false alarms by about 18–28 % at the expense of reduced true alarms by about 9–29 % and thus, being less advantageous than single variable threshold models. In contrast to precipitation based thresholds, relying on threshold models exclusively defined using hydrological variables such as groundwater levels can lead to improved landslide predictions due to their implicit consideration of long-term antecedent conditions until the day of landslide occurrence.
... Considering the effects of rainfall on the monitoring slope, the failure mode in nature usually performs two forms: one is deep slope failure which is mainly due to the saturation or even erosion of the topsoil by rainfall infiltration where the topsoil mainly contains the clay layer, weathered soil, tropical residual soil, etc. and the other kind is multiple shallow failures from slope toe and usually occurs in sandy soil slope or loess slope. It appears with the phenomenon that the slope gradually tends to be saturated from the bottom due to the rise of the groundwater table (Corominas et al. 2005). As a result, research will consider the following steps to prepare the sensor deployment and threshold setting: (1) conducting preliminary on-site geological surveys to build the slope model, (2) regarding the deployment of sensors under each borehole in the slope, both moisture sensors and acceleration sensors need to be deployed at different depths, and (3) testing the critical or saturated water content of the soil to define the threshold, set the threshold of deflection angle according to slope geometry, and set the threshold of the porewater pressure according to the depth of sensor location in each borehole. ...
... As a result, research will consider the following steps to prepare the sensor deployment and threshold setting: (1) conducting preliminary on-site geological surveys to build the slope model, (2) regarding the deployment of sensors under each borehole in the slope, both moisture sensors and acceleration sensors need to be deployed at different depths, and (3) testing the critical or saturated water content of the soil to define the threshold, set the threshold of deflection angle according to slope geometry, and set the threshold of the porewater pressure according to the depth of sensor location in each borehole. Since the failure mode is often characterized by multiple shallow landslides (Koizumi et al. 2018;Corominas et al. 2005), this study will focus on typical sandy soil slopes to give an example of threshold setting and EWS working. ...
Under heavy rainfall, landslide early warning system (LEWS) is considered to be an effective method for providing timely warnings, but previous LEWS presents deficiencies such as high cost, high power consumption, and difficulties in secondary development. To address the shortcomings, the current study developed a low-cost and sustainable LEWS that integrates the Internet of Things (IoT) and an off-the-grid solar energy-powered integrated platform for data acquisition, data transmission, and data analysis. Obtained data such as soil moisture content, pore water pressure, deflection angle, and real-time factor of safety (F s) are used as auxiliary warning indicators or cross-warning indicators. The LEWS considers three states before a landslide: monitoring state, alert state, and triggering state. Slope model tests and outdoor embankment slope tests were conducted to check the feasibility of the proposed LEWS. Results show that (1) compared with previous LEWS, the development cost and power consumption are greatly reduced, and the newly IoT-based LEWS provides an open architecture to meet different application scenarios and requirements and (2) a series of slope model tests based on LEWS successfully allows monitoring authorities to identify risk level, send warning signals, and predict potential movement so as to make enough time for risk management. The low-cost and standalone energy harvesting feature of the LEWS allows it to be applicable across the world.
... While most studies focusing on the kinematics of deep-seated landslides showed that prolonged periods of increased precipitation were necessary to trigger acceleration at the onset of the wet season [11][12][13]43,44 , the rapid response of Funu landslide to rainfall is surprising, notably given its large inferred depth (~30-80 m; response time is predicted to scale with depth). Such behaviour is, however, not unique 43,45 , and our very high InSAR sampling frequency may also capture a response that is usually missed with lower-sampling-frequency conventional InSAR or satellite optical measurements. Yet many environmental factors-tropical climate, weathering, tectonic settings and urban development-are acting on Funu hydrology and may each influence its relatively singular kinematic response. ...
... Yet many environmental factors-tropical climate, weathering, tectonic settings and urban development-are acting on Funu hydrology and may each influence its relatively singular kinematic response. While preferential infiltration pathways are commonly believed to play a key role in explaining rapid landslide responses 38,45,46 , intense rainfall associated with tropical climate 30 may exacerbate their relative importance. Slope mechanical and hydrological properties are also known to be strongly influenced by weathering process 31,47,48 , a central component of tropical geomorphology 30 . ...
The movement of large, slow-moving, deep-seated landslides is regulated principally by changes in pore-water pressure in the slope. In urban areas, drastic reorganization of the surface and subsurface hydrology—for example, associated with roads, housings or storm drainage—may alter the subsurface hydrology and ultimately the slope stability. Yet our understanding of the influence of slope urbanization on the dynamics of landslides remains elusive. Here we combined satellite and (historical) aerial images to quantify how 70 years of hillslope urbanization changed the seasonal, annual and multi-decadal dynamics of a large, slow-moving landslide located in the tropical environment of the city of Bukavu, Democratic Republic of the Congo. Analysis of week-to-week landslide motion over the past 4.5 years reveals that it is closely tied to pore-water pressure changes, pointing to interacting influences from climate, weathering, tectonics and urban development on the landslide dynamics. Over decadal timescales, we find that the sprawl of urbanized areas led to the acceleration of a large section of the landslide, which was probably driven by self-reinforcing feedbacks involving slope movement, rerouting of surface water flows and pipe ruptures. As hillslopes in many tropical cities are being urbanized at an accelerating pace, better understanding how anthropogenic activity influences surface processes will be vital to effective risk planning and mitigation.
... The Vallcebre landslide is in Northeastern Pyrenees, 140 km from Barcelona (Spain), and it develops in stiff clays with shale and gypsum layers over a limestone bedrock. The experimental data of this well-monitored landslide come from wire extensometers and electronic piezometers that show a close correlation between displacements and groundwater level, in turn associated with rainfall (Corominas et al. 2005). ...
... The slope displacements appear related to river flow fluctuations, snow melting, and rainfalls, while Follacci et al. (1988) relate the previously mentioned occasional reactivation with the failure of the gneissic bedrock in the northwestern block. Fig. 10 Forecasting the evolution of the Vallcebre landslide (Corominas et al. 2005) calibrated with increasing number of recorded data. Time in days (abscissas); displacements in mm, panel a, velocity in mm/day, panel b (ordinates). ...
This paper proposes a new, physically based, and mathematically consistent method for predicting the evolution of existing landslides and first-failure phenomena based on slope displacement measurements. The method is the latest step in a long-term research program and, as such, uses the preliminary framework introduced in two previous papers. The first characterizes slope movements through a limited number of displacement trends, and the second analyzes their dynamic characteristics. The approach is here extended to the prediction of landslide evolution and its validity and effectiveness are tested on landslides well known in the scientific literature for the accuracy of the studies carried out and, in some cases, for the consequences they have caused. Although the results obtained so far are very encouraging, in full awareness of the relevance and complexity of the subject matter, the authors emphasize that the method should be used, in the current state of knowledge, only by experienced professionals and especially for research purposes.
... Regarding the interbedding characteristics and water sensitivity of red bed strata, key causes of instability include strata with different lithology (Wu et al. 2017;Miao et al. 2014) and environmental hydrological factors, such as rainfall (Wu et al. 2017;Cui et al. 2017;He et al. 2021) and groundwater (Corominas et al. 2005;van Asch et al. 2009;Brönnimann 2011). The stratigraphic structure determines the sliding mode and hydrological factors can induce catastrophic landslide failures (Nian et al. 2013;Jiao et al. 2014;Song et al. 2018). ...
... Therefore, fluctuations of groundwater levels have a significant impact on the deformation of red bed landslides. Most previous studies (Corominas et al. 2005;van der Spek et al. 2013;Ronchetti et al. 2009) considered landslide bodies as a whole to study the relationship between groundwater level changes and displacements, neglecting zoning characteristics. In this study, significant differences in deformation modes were observed between US and LU of the Abi landslide. ...
Strata in red bed areas have typical characteristics of soft-hard interbedding and high sensitivity to water. Under the comprehensive action of internal stratigraphic structure and external hydrological factors, red bed landslides have highly complex spatiotemporal characteristics, presenting significant challenges to the prevention and control of landslide disasters in red bed areas, especially for slope and tunnel engineering projects. In this study, we applied an interdisciplinary approach combining small baseline subset interferometric synthetic aperture radar (SBAS-InSAR), deep displacement monitoring, and engineering geological surveying to identify the deformation mechanisms and spatiotemporal characteristics of the Abi landslide, an individual landslide that occurred in the red bed area of Western Yunnan, China. Surface deformation time series indicated that a basic deformation range developed by March 2020. Based on InSAR results and engineering geological analysis, the landslide surface could be divided into three zones: an upper sliding zone (US), a lower uplifted zone (LU), and a toe zone (Toe). LU was affected by the structure of the sliding bed with variable inclination. Using deep displacement curves combined with the geological profile, a set of sliding surfaces were identified between different lithology. The groundwater level standardization index (GLSI) and deformation normalization index (DNI) showed different quadratic relationships between US and LU. Verification using the Pearson correlation analysis shows that the correlation coefficients between model calculated results and measured data are 0.7933 and 0.7577, respectively, indicating that the DNI-GLSI models are applicable. A fast and short-lived deformation sub stage (ID-Fast) in the initial deformation stage was observed, and ID-Fast was driven by concentrated rainfall.
... Compared with phenomenological models, physical models consider various factors such as the landslide complex geometry, spatial variability of geotechnical properties, and 3D groundwater flow, which can provide an enhanced understanding of the physical mechanism of the landslide process. For example, Corominas et al. [7] studied the rheology and viscosity properties of geo-materials and then established a physicsbased dynamic model to predict the landslide displacement. Herrera et al. [16] calibrated a one-dimensional infinite physically based model with viscoplastic behavior through inverse analysis, which was adopted to predict the displacement of the Portalet landslide. ...
... As such, the formulation of the simultaneous prediction intervals shown in Eqs. (7)(8) is slightly different from that of the simultaneous confidence intervals shown in Eqs. (3)(4), and the residual variance of the predictionsr 2 ðx i Þ (see Eq. 6) should be incorporated in the simultaneous prediction intervals. ...
For landslide displacement, interval predictions are generally more realistic and reliable compared with traditional point predictions. This paper presents a new interval prediction method for landslide displacement integrating dual-output least squares support vector machine (DO-LSSVM) and particle swarm optimization (PSO) algorithms. In this new method, the PSO algorithm is employed to optimize coefficients of the least squares support vector machine (LSSVM) model for obtaining point prediction results, and the interval prediction of the landslide displacement is made based on the dual-outputs obtained from the DO-LSSVM model. To assess the rationality of the predictions, three performance evaluation indicators, including the prediction interval coverage probability (PICP), normalized mean prediction interval width (NMPIW), and coverage width-based criterion (CWC), are established. Case studies of the Tanjiahe landslide and the Baishuihe landslide in the Three Gorges Reservoir region are then used to demonstrate the effectiveness of the proposed method in predicting the landslide displacement interval. The case study results demonstrate that this new method has the best overall performance compared with other existing methods, and this new method can provide accurate and reliable results for the medium- to long-term interval prediction of landslide displacement.
... Although inclinometric and piezometric measurements were not available for this study, the MFRB are very similar in lithology and clay mineralogy to other "red bed" deposits such as those from the Qinghai-Tibet Plateau (Xin et al. 2018) or the varicoloured clay formation (Fiore and Mongelli 1991), for which inclinometric and pore water pressures were observed for several landslides. For these deposits, increases in displacement rates were correlated to increased pore water pressures (Rosone et al. 2018;Xin et al. 2018), yet even at constant groundwater levels or constant water contents, continuous deformations in inclinometers were still observed (Corominas et al. 2005;Di Maio et al. 2013). Furthermore, deformations in relation to water infiltration have been experimentally observed and it seems that water infiltration alone could ultimately induce failure (Gui and Wu 2014;Hu et al. 2017), even without the development of pore water pressure. ...
... In relation to physical properties, as water contents increase on pre-existent slip surfaces, the water content at the PL or LL will be surpassed. This in turn will cause softening exerted as plastic movement, as it typically happens in slow-moving landslides (Corominas et al. 2005;Di Maio et al. 2013;Xin et al. 2018). ...
The southern slope of the Cetățuia-Hoia Hill, located in the urban setting of Cluj-Napoca (Romania), consists of clayey deposits interbedded with sands and sandstones. The slope deposits belong to the Moigrad Formation and are representative of “red bed” continental deposits found across the world. Although documented as a landslide-prone area, the hillslope receives increased attention due to urban development and real estate pressure. The slope was affected by an old, deep-seated landslide; mudflows; and anthropogenic interventions. The stability of the old landslide is close to equilibrium (1.35) and its reactivation may be triggered by rainwater infiltration. The Moigrad Formation deposits are mostly active, expansive, and display medium to high plasticity. Their shearing resistance is described by effective friction angles of 6.7–33.7° and effective cohesive strengths of 7–122 kPa. With regard to mineralogy, the deposits are made up of quartz, feldspar, calcite, dolomite, and phyllosilicates (micas, chlorite, kaolinite, and minerals belonging to the smectite group), while their clay-sized fraction (< 2 µm) is made up of illite–smectite interstratifications, illite, chlorite, kaolinite, and quartz. The physical and mechanical properties of the deposits are closely related to the type and amount of clay-sized minerals, especially to the illite–smectite interstratifications and illite, which are the main components in the clay-sized fraction. Interactions between these components and water infiltrated within the hillslope are proposed as driving mechanisms for landslide reactivation and as active phenomena undermining the stability of the area.
... Some authors believe that earthflows are the most effective geomorphic agent influencing the landscape evolution in hillslope catchments (Mackey, 2009;Tucker, 2015). The long-term activity of these landslides is controlled by tectonic uplift, weathering, soil use, and climate (Coe et al., 2003;Corominas et al., 2005), while massive failures are mostly caused by discrete rainfall events. Still, the relationship between rainfall and landslide movement is extremely difficult to establish because of the complex hydrology of fine-grained soils (Kenney and Lau, 1984;Haneberg, 1991;Iverson, 2000;Berti and Simoni, 2010). ...
... Despite their moderate speed, earthflows represent the primary danger in clay hillslopes and are responsible of incessant damages to buildings, roads and infrastructure (Keefer and Johnson, 1983;Bertolini, 2010;Bardi et al., 2017). In the Mediterranean area, earthflows are widespread in Italy (Giusti et al., 1996;Bertolini and Pizziolo, 2008), France (Malet et al., 2000;Schmutz et al., 2009), Spain (Corominas et al., 2005;Dominguez-Cuesta et al., 2007) Croatia (Jovančević and Arbanas, 2012;Ž ic et al., 2015) and Greece (Depountis et al., 2010). These mass movements can have a dramatic economic impact on local communities and highlight the urgent need for progressing our knowledge toward more effective strategies of forecasting and mitigation. ...
Earthflows are widespread phenomena in the Mediterranean area. These landslides involve fine-grained soils and clay-bearing rocks, and despite their low speed are responsible for significant economic losses in vast areas. The dynamics of these landslides is still relatively obscure thus reducing our ability to forecast and mitigate their effects. In this study, we present a methodological approach for the characterization of active earthflows based on the combination of geophysical surveys, laboratory tests, and empirical formulas. Geophysical surveys consist of periodic measurements of Rayleigh wave velocities repeated over time to evaluate the change of stiffness with time of the landslide material. Laboratory tests combine Atterberg limits, fall cone and oedometric tests and allow to constrain the empirical correlations between geophysical and geotechnical properties. The method is designed to obtain relevant data when direct methods like boreholes or geotechnical soundings are not possible for safety reasons, with the aim of investigating the solid-to-fluid transition than can occur in rapid earthflows. We applied this approach to study the Montevecchio landslide (Northern Apennines of Italy), an active earthflow in young marine clays which was affected by multiple reactivations in the recent years. Results show that after a surge the earthflow material is very soft (shear wave velocity in the order of 50–60 m/s) and characterized by a high water content. However, the exact value of the Liquidity Index remains unknown due to the lack of direct measurements and to the uncertainty dictated by the empirical relationships.
... Groundwater level fluctuation (GWLF) is one of the most important factors affecting the kinematic of slow-moving and deep-seated landslides (Leroueil et al. 1996;Wieczorek 1996;van Asch et al. 1999van Asch et al. , 2009Schuster and Wieczorek, 2002). The groundwater table rise in response of heavy or prolonged rainfall has often direct connections with the reactivation of suspended and dormant landslides (Matsuura et al. 2008;Simoni et al. 2004;) and the acceleration of active slope movements (Caris and van Asch 1991;Mantovani et al. 2000;Corominas et al. 2005;Cascini et al. 2010;Prokešová et al. 2013;Zhi et al. 2016;Wei et al. 2019a), along with the localized reactivations or residual movements affecting relict landslides (Mather et al. 2003;Discenza et al. 2011;Lopez Saez et al. 2012Boon et al. 2015. ...
... The stabilization of slow and deep-seated landslides is one of the most difficult tasks in the field of engineering geology (Holtz and Schuster 1996;Popescu and Sasahara 2009), especially in case of large and complex phenomena whose kinematic is influenced by GWLF (Corominas et al. 2005;van Ash et al. 2007van Ash et al. , 2009Prokešová et al. 2013). The most used engineering solutions often consist of traditional drainage works (Hutchinson 1977;Eberhardt et al. 2007;Pulko et al. 2014), sometimes coupled with retaining structures (Mikoš et al. 2005;Corsini et al. 2006). ...
This study presents the employment of automatic deep drainage systems to stabilize the Mendatica landslide, one of the largest relict landslides of western Liguria (north-western Italy). Despite the relict state of activity of the main landslide body, a residual kinematic still affects the sector of accumulation zone over which the small village of Mendatica is located and where sharp reactivations of the movements were frequently recorded after severe rainstorms. The aim of this research is to investigate both the efficiency and
effectiveness of Electropneumatic Drains® during an extreme rainstorm based on geotechnical monitoring data. On the one hand, the continuous groundwater level measurements allowed to examine the performance of two alignments of wells equipped with electropneumatic pumps during a severe 5-day rainfall event occurred in November 2016, when cumulative rainfalls equalled approximately 800 mm at Mendatica. On the other hand, the subsurface displacements measured from inclinometers before and after the activation of the two draining diaphragms enabled the evaluation of the influence of the automatic deep drainage on the landslide kinematic. The analysis of the hydraulic response of the two drainage lines reveals that, despite the severity of the recorded rainfall values, the pumping wells efficiently worked during the rainstorm since they successfully controlled the increase of hydraulic heads. Furthermore, the outcomes of this study show that, under severe rain conditions, the presence of the Electropneumatic
Drains® has mitigated the magnitude of the landslide displacements preventing the development of rapid accelerations of the slope movements.
... 1-14) for purely hydrologic studies, and comparing it with geophysical observations to better understand infiltration processes without requiring any hydrological measurement. (Corominas et al., 2005). ...
... The water then progressively infiltrates the ground, with a delay, leading to an elevation of the groundwater level and pore pressure (Iverson, 2000). The displacement of a slow reactivated landslide can be nearly linear with the groundwater level (Corominas et al., 2005), as long as no failure occurs. The groundwater elevation can cause displacement through an increase of shear stress and a rigidity diminution for clayey material (Carrière et al., 2018b;Mainsant et al., 2015Mainsant et al., , 2012a. ...
Landslide early-warning systems are based primarily on monitoring the displacement of the landslide. This work develops a new technique for monitoring these displacements, using radio-frequency identification (RFID) passive tags and phase-based location technique. This technique is deployed for the first time outdoors and for several months. Outdoor conditions revealed strong environmental influences
due to temperature variations, moisture, snow and vegetation. These can cause a ±20 cm measurement uncertainty over a year, which is too large for landslide monitoring applications. The correction of these effects allows reaching the accuracy of ±1 cm under normal conditions, ±8 cm with snow and ±4 cm with dense high grass. The remaining effects due to snow and grass are explained by the influence of this material on the direct propagation, on the multipath interferences and on the antennas. This measurement system has been deployed on the Pont-Bourquin landslide for five months. The results validate the technique for landslide monitoring applications. The technique also shows the operational benefits of robustness to
bad weather, easy maintenance and low-cost material, compared to conventional techniques (extensometer, GPS, total station).
This thesis then studies two complementary monitoring methods that had recently been shown to provide precursors to landslide rupture. First, ambient seismic noise interferometry is used to detect a drop of shear-wave velocity prior to a rupture. The seismic method was studied in the literature to identify what must be developed to use this technique in an operational early-warning system. It requires getting rid of daily and seasonal environmental influences, choosing the processing parameters appropriate to the monitored landslide, and improving the temporal resolution below one day while keeping a stable enough signal. The other method consists of inverting an impulse response between rainfall and displacement rate, with a high resolution. It can shed light on complex infiltration processes (e.g.
infiltration with two different delays at Pont-Bourquin) and detect their abnormal evolution across time. These developments should improve landslide operational monitoring with a low budget.
... Sometimes these warnings provide less reaction time to take necessary precautionary measures. Therefore, this approach can be enhanced by utilizing physics-based landslide models, e.g., sliding-consolidation model (Hutchinson, 1986), viscoplastic sliding-consolidation model (Corominas et al., 2005;Herrera et al., 2013;Bernardie et al., 2014) and extended sliding-consolidation model (Iverson, 2005) to predict future displacement/velocity. A similar approach has already been studied in (Corominas et al., 2005;Herrera et al., 2013;Bernardie et al., 2014). ...
... Therefore, this approach can be enhanced by utilizing physics-based landslide models, e.g., sliding-consolidation model (Hutchinson, 1986), viscoplastic sliding-consolidation model (Corominas et al., 2005;Herrera et al., 2013;Bernardie et al., 2014) and extended sliding-consolidation model (Iverson, 2005) to predict future displacement/velocity. A similar approach has already been studied in (Corominas et al., 2005;Herrera et al., 2013;Bernardie et al., 2014). These models are sensitive to the initial conditions, parameter values, and input to the model, i.e., rainfall, water table height, or pore water pressure time-series. ...
The paper presents a combined state and parameter estimation for a landslide model using a Kalman filter. The model under investigation is based on underlying mechanics that depicts a landslide behavior. This system is described by an Ordinary Differential Equation (ODE) with displacement as a state and landslide geometrical and material properties as parameters. The Kalman filter approach is utilized on a simplified model equation for state and parameter estimation. Finally, the presented approach is validated by two illustrative examples, the first one a synthetic case study and the second one on Super-Sauze landslide data taken from the literature.
... Physical models and data-based models have been proposed to predict landslide displacement (e.g., Jiang et al 2011;Li et al 2018). Data-based models are often preferred because they are simpler, can give accurate predictions and involve lower costs (Corominas et al 2005;Zhou et al. 2018). Du et al (2013) predicted the displacement of colluvial landslides in the TGRA with a back propagation neural network (BPNN). ...
... The residual strength and its rate dependency are primary controls of landslide motion (Schulz & Wang, 2014). Field observations of slow-moving landslides often show a direct correlation between the velocity and the ground water level (Bonzanigo et al., 2007;Corominas et al., 2005;Van Asch et al., 2009). During rainy periods and the associated rise of the water level, the effective stresses in the shear zone decrease and so does the resistance. ...
The behaviour of slow‐moving landslides is controlled by the residual strength of the shear zone. Despite their mobile state, such slides can often withstand extreme events like heavy rainfalls and earthquakes. A rate‐hardening in the shear zone is suspected to be one of the main stabilizing factors and has been well investigated, in particular for clayey soils. Soils from steep alpine landslides, on the other hand, are often dominated by silts and sands with various clay content, and while understanding of their rate dependency is less advanced, it remains critical for the reliable risk assessment. In this article, an improved ring shear apparatus is presented and applied to investigate rate, pore water pressure and temperature effects in landslide shear zones. The testing program on samples from two alpine landslides in Switzerland reveals a moderately positive rate effect explaining their mobile state. An achieved insight into the thermo‐hydro‐mechanical processes of fast shearing provides physical evidence to the widely debated hypothesis on generation of excess pore water pressure due to frictional heating. However, for the tested materials this effect only occurs after extended shearing and does not lead to a complete loss of shear strength. Based on that and the observed positive rate effects, catastrophic failure seems unlikely for these landslides. At the same time, the results suggest that for less permeable soils, frictional heating may indeed be a source of negative rate effect during very rapid shearing.
... The resulting slow residual friction angle at a velocity of 0.01 mm/min from different samples lies in the range of φ r 0 = 24 • ± 1 (Fig. 10b), which is well below the minimum required value based on the strength-reduction analysis of the most stable scenario. Such a discrepancy between field and laboratory is a common problem and can have various causes (Corominas et al., 2005;van Asch et al., 2007). In this case, one of the main reasons is that only the fraction smaller than 2 mm could be tested in the ring shear apparatus, leaving gravel size particles constituting approximately 20% of material by weight excluded. ...
... In this study they are modelled with the same permeability, which allows for reduction in the number of model parameters. This simplification is justified because the thickness of shear zones, typically ranging from millimeters to decimeters [47][48][49][50] , is orders of magnitude smaller than that to the adjacent layers. Consequently, the shear zone contribution to seepage is small and not sensitive to its permeability. ...
Active slow-moving landslides exhibit very different coseismic and postseismic behaviour. Whereas some landslides do not show any postseismic acceleration, there are many that experience an increased motion in the days to weeks following an earthquake. The reason for this behaviour remains debated and the underlying mechanisms are only partially understood. In recent years, it has been suggested that postseismic acceleration is caused by excess pore water pressures generated outside of the shear zone during seismic shaking, with their subsequent diffusion into the shear zone. Here we show that this hypothesis is indeed plausible and hydro-mechanically consistent by using a basic rate-dependent physical landslide model. Our simulations provide insight into the landslide behaviour in response to seismic shaking and its main controlling parameters: preseismic landslide velocity, rate-dependency of soil strength in the shear zone, hydro-mechanical characteristics of the adjacent soil layers and the earthquake intensity.
... The effective normal stress and shear resistance of slip surface reduce as pore water pressure rises, which promotes slope instability (Corominas et al. 2005, Matsuura et al. 2008, Schulz et al. 2009, Tommasi et al. 2006). On the other hand, it is reported that ground temperature changes are likely to affect significant portions of the slip surface, especially for shallow landslides (Lapham 1989, Matsuura et al. 2003, Shibasaki et al. 2016. ...
This paper presents experimental and numerical investigations regarding the effect of temperature on the residual strength of Bentonite at slow-to-moderate shearing velocities. In order to understand the trigger mechanism of slow-moving landslides, we investigated the effect of temperature on the shear strength of slip surfaces. We performed ring-shear tests on Bentonite samples at various temperatures and rates. The test results show that the residual shear strength of Bentonite is both rate and temperature dependent. Under relatively slow shearing rates, strength was gained as temperature increased; in contrast, under relatively high shearing rates, strength was decreased as temperature increased. A non-isothermal viscoplastic model is proposed to simulate the observed behaviour of a ring- shear samples of Bentonite subjected to drained heating under residual conditions. The developed model was implemented in finite element computer code for THM analysis of porous media, and experimental results were numerically simulated.
... Los métodos estadísticos más usados son bivariados (Aleotti y Chowdhury, 1999;Süzen y Doyuran, 2004;Lee, 2005), multivariados (Carrara, 1983;Gorsevski et al., 2000;Lee y Pradhan, 2007) e inteligencia artificial (Lee et al., 2004;Ermini et al., 2005). Por su parte, los modelos de base física combinan análisis hidrológicos y geotécnicos para evaluar la estabilidad de laderas usando el factor de seguridad en aplicaciones de escala local (Corominas et al., 2005;van Westen et al., 2008). Generalmente, utilizan el criterio de falla de Mohr-Coulomb y análisis de equilibrio límite mediante la ecuación de talud infinito, con modelos hidrológicos de flujo subsuperficial en un estado estacionario o transitorio en condiciones saturadas o parcialmente saturadas. ...
Los estudios básicos de susceptibilidad y amenaza por la ocurrencia de movimientos en masa son un elemento fundamental para la actualización de los planes de ordenamiento de los municipios del territorio colombiano. Dado lo anterior, la Ley 1523 de 2012 establece la política marco, y el Decreto 1807 de 2014, compilado en el 1077 de 2015, establece los lineamientos técnicos que tales estudios deben seguir y las condiciones mínimas que se deben cumplir. Por este motivo, se realizó una selección de algunas metodologías reconocidas en la literatura, que, al ser adecuadas y validadas según las condiciones propias de cada municipalidad, pueden ser utilizadas para la realización de tales estudios, sean tanto para el área rural y para suelo urbano y de expansión, como para cada uno de los factores que pueden detonar estos eventos
... Displacement prediction is an enduringly important topic in landslide research, through which landslide responses to influencing factors and future stability can be learned. Numerous models have been proposed to reach an accurate depiction of the step-like movement of reservoir landslides, which can be normally categorized as empirical models (Van Asch et al. 2009;Bernardie et al. 2015), hydro-mechanical models (Xia et al. 2013;Jian et al. 2014), viscoelastoplasticity models (Desai et al. 1995;Corominas et al. 2005), and computational intelligence technology-based models (Xu and Niu 2018;Zhou et al. 2018;Li et al. 2020). Although satisfying prediction performance may be realized, many parameters are generally involved in such models, and some parameters lack sound physical meanings . ...
Variations of reservoir water level and seasonal precipitation have reactivated or accelerated many reservoir landslides in the Three Gorges Reservoir area since impoundment in 2003. Updated daily monitoring data since 2017 reveals details about the step-like pattern of annual movement of the Baijiabao landslide, a large creeping landslide with a maximal cumulative surface displacement of 0.2 m over this 2-year period. The spatiotemporal deformation characteristics show that mass movement was greatest in 2017 and boundary cracks exhibit more frequent steps and are more sensitive to hydraulic factors than surface displacement. Acceleration periods are triggered when the reservoir water level falls below 153 m above mean sea level, with most annual movement occurring before the reservoir rises back to that critical level. The rate of daily surface movement is controlled by the daily variation of reservoir water level and by cumulative rainfall during the previous 1 to 7 days. The movement responses vary from different years and movement periods, but the one-factor critical-level model can effectively predict surface movement. The correlation between surface displacement rate and reservoir water level also comprehensively indicates the association between landslide movement and hydraulic factors including rainfall and variation of reservoir water level. Low reservoir level and its drawdown, and heavy or continuous rainfall, increase hydraulic gradients and change stress conditions, which destabilize the Baijiabao landslide and accelerate its surface movement.
... Helmstetter et al. (2004) utilized a slider block friction model to analyze landslide displacement and velocity data. Corominas et al. (2005) developed a momentum equation in which a viscous term was added to predict the landslide displacements and velocities in water-triggered landslides. Mufundirwa et al. (2010) proposed an empirical physics model to forecast the failure time of landslides based on slope gradient and performed laboratory experiments for validation. ...
Landslides are geohazards of major concern that can cause casualties and property damage. Short-term landslide displacement prediction is one of the most critical and challenging tasks in landslide deformation analysis, and is beneficial for future hazard mitigation. In this research, a novel short-term displacement prediction approach using spatial-temporal correlation and a gated recurrent unit (GRU) is proposed. The proposed approach is a unified framework that integrates time-series instant displacements collected from multiple monitoring points on a failing slope. First, a spatial-temporal correlation matrix, including the pairwise Pearson’s correlation coefficients, was studied based on the temporal instant displacement data. Then, the extracted spatial features were integrated into the time-series prediction model using GRU. This approach combines both spatial and temporal features simultaneously and provides enhanced prediction performance. In the last step, a comparative analysis against other benchmark algorithms is performed in two case studies including the conventional time-series modeling approach and the spatial-temporal modeling approach. The computational results show that the proposed model performs best in terms of performance evaluation metrics.
... Therefore, the monitoring and prediction of the GWL is an essential part of the landslide hazard analysis 5 . There is a correlation between the landslide displacement velocity and the GWL 6,7 . Van Asch 8 considered that the increase of the GWL could accelerate the deformation of landslides more than the decrease effect. ...
The monitoring and prediction of the groundwater level (GWL) significantly influence the landslide kinematics. Based on the long-term fluctuation characteristics of the GWL and the time lag of triggering factors, a dynamic prediction model of the GWL based on the Maximum information coefficient (MIC) algorithm and the long-term short-term memory (LSTM) model was proposed. The Sifangbei landslide in the Three Gorges Reservoir area (TGRA) in China, wherein eight GWL monitoring sensors were installed in different locations, was taken as a case study. The monitoring data represented that the fluctuation of the GWL has a specific time lag concerning the accumulated rainfall (AR) and the reservoir water level (RWL). In addition, there were spatial differences in the fluctuation of the GWL, which was controlled by the elevation and the micro landform. From January 19, 2015, to March 6, 2017, the measured data were used to set up the predicted models. The MIC algorithm was adopted to calculate the lag time of the GWL, the RWL, and the AR. The LSTM model is a time series prediction algorithm that can transmit historical information. The Gray wolf optimization (GWO) algorithm was used to seek the most suitable hyperparameter of the LSTM model under the specific prediction conditions. The single-factor GWO-LSTM model without considering triggering factors and the support vector machine regression (SVR) model were considered to compare the prediction results. The results indicate that the MIC-GWO-LSTM model reached the highest accuracy and improved the prediction accuracy by considering the factor selection process with the learner training process. The proposed MIC-GWO-LSTM model combines the advantages of each algorithm and effectively constructs the response relationship between the GWL fluctuation and triggering factors; it also provides a new exploration for the GWL prediction, monitoring, and early warning system in the TGRA.
... and their motion is closely linked to local groundwater conditions (Corominas et al., 2005;Iverson & Major, 1987;Murphy et al., 2022). Furthermore, the hydrologic controls on slow-moving landslides, via pore pressure changes, are akin to the hydrologic controls on faults (Bhattacharya & Viesca, 2019;Cappa et al., 2019), glaciers (Minchew & Meyer, 2020;Moon et al., 2014), and rock glaciers (Cicoira et al., 2019;Kenner et al., 2017), and therefore investigating these landslides allows us to better understand each system. ...
Plain Language Summary
Landslides are often triggered by precipitation and as a result are sensitive to local climate conditions. Climate change is impacting precipitation patterns worldwide and therefore will likely have a profound influence on landslide activity over the coming decades. Here we use standardized open‐access satellite radar data to assess landslide sensitivity to precipitation across a large rainfall gradient in California between 2015 and 2020. During this time period, our study area experienced some of the wettest and driest years on record, which is a precipitation pattern that is predicted to become the norm over the next century in California. We found that landslides in both wet regions of northwestern California and dry regions of southwestern California were similarly sensitive to seasonal and multi‐year changes in precipitation. These landslides moved faster than average during wet years and slower than average during dry years. Our findings further confirm landslide sensitivity to climate change under diverse hydroclimate conditions and highlight the need to establish a long time series of landslide behaviors that can be used to better predict future landslide activity.
... Further researches were conducted to predict the timing of rock falls and rock slides based on long-term deformation monitoring [13,14]. In addition, there were proposed methods based on inverse velocity [15], displacement gradient [16], and landslide triggers [17]. These mechanism-and model-based methods can provide explanations in terms of landslide mechanisms, but can be complex, time-consuming, and not very generalizable [18]. ...
Effective landslide hazard prevention requires accurate landslide prediction models, and the data-driven approaches based on deep learning models are gradually becoming a hot research topic. When training deep learning models, it is always preferable to have a large dataset, while most available landslide monitoring data are limited. For data missing or data sparseness problems, conventional interpolation methods based on mathematical knowledge lack mechanism interpretability. This paper proposes that numerical simulations can be used to expand the deep learning dataset we need. Taking the Jiuxianping landslide in the Three Gorges Reservoir Area (TGRA) as the geological background, a finite element numerical model was established, and the landslide displacement time series data were solved considering the boundary conditions of reservoir water level change and precipitation. Next, based on three metrics: Euclidean distance, cosine similarity, and dynamic time warping (DTW) distance, the time series similarity between the displacement data obtained from simulation and data obtained from actual monitoring were verified. Finally, the combined deep learning model was built to predict the displacement of the Jiuxianping landslide. The model was trained on both the simulated and monitored datasets and tested by the last 12 monitored data points. Prediction results with the testing set showed that the models trained using the expanded training set from numerical simulations exhibited lower prediction errors, and the errors had a more concentrated distribution. The results suggest that this landslide displacement prediction method combining numerical simulation and deep learning can solve the problem of inadequate datasets due to low monitoring frequency, as well as provide an interpretation of the physical mechanism for data vacancy filling.
... Numerous approaches have been developed for the purpose of landslide displacement prediction. They can be divided into two main types: physically-based approaches and data-driven approaches [8][9][10]. Among these models, the physically-based models mainly take geotechnical characteristics into analysis and quantify the slope displacement by Convolutional neural networks are widely applied in extracting features from multiple dimensions data with Euclidean space [33,34]. ...
Landslide displacement prediction is an essential base of landslide hazard prevention, which often needs to establish an accurate prediction model. To achieve accuracy prediction of landslide displacement, a displacement prediction model based on a salp-swarm-algorithm-optimized temporal convolutional network (SSA-TCN) is proposed. The TCN model, consisting of a causal dilation convolution layer residual block, can flexibly increase the receptive fields and capture the global information in a deeper layer. SSA can solve the hyperparameter problem well for TCN model. The Muyubao landslide displacement collected from a professional GPS monitoring system implemented in 2006 is used to analyze the displacement features of the slope and evaluate the performance of the SSA-TCN model. The cumulative displacement time series is decomposed into trend displacement (linear part) and periodic displacement (nonlinear part) by the variational modal decomposition (VMD) method. Then, a polynomial function is used to predict the trend displacement, and the SSA-TCN model is used to predict the periodic displacement of the landslide based on considering the response relationship between periodic displacement, rainfall, and reservoir water. This research also compares the proposed approach results with the other popular machine learning and deep learning models. The results demonstrate that the proposed hybrid model is superior to and more effective and accurate than the others at predicting the landslide displacement.
... The increase in pore water 30 pressure is normally due to the rain water infiltration in soil which leads to the increase 31 in pore water pressure along with the decrease in shear strength of soil (Iverson, 2000, 32 Godt, 2009, Zhang, 2015. The stability of a soil slope is also greatly affected by the 33 increase of ground water table (Corominas, 2005, Ledesma, 2009, Conte, 2018b with an increase in groundwater levels (Mantovani, 2000). Similarly there are many other research work conducted which investigated and monitored rain water runoff, and 41 concluded that groundwater levels are directly linked to slope movement (Zhi, 2016, 42 Conte, 2018a, Bogaard, 2018, Cotecchia, 2016, Hong, 2011. ...
Earth-fill dam failure and landsliding during heavy rainfall and flooding is a common problem observed all over the world. This paper examines and discusses the causes of landsliding due to rainfall and flooding. Climatic rainfall data are interconnected with rainfall precipitation and its effect on the increase in pore water pressure inside soil slopes. Various soil slopes with different geometries and material properties are analysed, and the variation in pore water pressure and the slope factors of safety (FSs) are calculated. Correlations between the groundwater level (GW L ) and slope FS are developed in both seismic and non-seismic situations. Correlations between shear strength (τ), shear stress (σ) and FS are also developed. The Kotkai landslide in Pakistan is considered a case study for cross-checking the correctness of the developed correlations. These correlations can be applied to design a safe soil slope in intense flood and rainfall areas.
... It is a slow-moving translational landslide, activated by recurring factors. A comparison between rainfall, groundwater-level changes, and landslide displacements, systematically recorded every 20 minutes since 1996 for this landslide, shows that the transitions between subsequent activity stages is dictated by periodic rainfall [Corominas et al. 2000;2005]. Figure 8, top panel, reports the experimental data points of the cumulative displacement trends for the period 25 January 1997 to 21 December 1998 (circle marks), together with the corresponding power-law approximation (solid lines). ...
... Piezometer sensors are commonly installed in boreholes in the ground. Monitoring groundwater conditions can also be used to understand the stability state of the slope and can be integrated with other environmental information to study the evolution of possible failures in the future (Corominas, Moya, Ledesma, Lloret, & Gili, 2005). There are many types of piezometers; those commonly used for landslide monitoring applications are standpipe, pneumatic, and electric. ...
... strain hardening during shearing or development of negative porewater pressures in zones of extension), geometrical/topographical or nonfrictional (e.g. rheological) mechanics can modify or even reverse this relationship (Corominas et al., 2005;Massey et al., 2013van Asch et al., 2009). ...
Hillslope (in)stability is governed by the balance of stability factors. If stability is lost, gradually or instantly, slope failure ensues. Assessing the causes of instability is useful for hazard analysis and mitigation, and for considering the role of landslides in landscape systems and evolution. Geological and geomorphological conditions (e.g. material type, strength and structure and hillslope geometry) predispose slopes to failure; knowledge of these conditions can help to predict the location, types and volumes of potential failures. The timing of failure, often by a specific trigger, can be anticipated by detecting and assessing movement patterns, establishing triggering thresholds or using probabilistic methods. However, predicting timing remains challenging due to the difficulty of measuring material strength degradation which can lead to failure with no readily observable trigger. This chapter describes concepts of stability and explores some of the major causes and triggers of hillslope failure and opportunities for further research.
... Landslide is considered as one the most perilous geohazards in the hilly and mountainous regions over the globe where harsh damages are imposed on the residents as well as the environment and economy of the regions (Solaimani et al. 2013;Sujatha et al. 2012). Landslide forecasting is the most challenging and critical task of landslide studies Helmstetter et al., 2004;Corominas et al., 2005;Gao, 2006). An accurate prediction of a landslide event can be used as a guideline for swift pre-warning, forecasting, and engineering control practices. ...
Landslides are among the most destructive natural hazards with severe socio-economic ramifications all around the world. Understanding the critical combination of geoenvironmental factors involved in the occurrence of landslides can mitigate the adverse impacts ascribed to them. Among the several scenarios for studying and investigating this phenomenon, landslide susceptibility mapping (LSM) is the most prominent method. Applying the machine learning (ML) algorithms integrated with the geographic information systems (GIS) has become a trending means for accurate and rapid landslide mapping practices in the scientific community. Support vector machine (SVM) has been the most commonly applied ML algorithm for LSM in recent years. The current study aims to implement different SVM kernel functions including polynomial kernel function (PKF) (degree 1 to 5), radial basis function (RBF), sigmoid, and linear kernels, for a GIS-based LSM over the Tabriz Basin (TB). To this end, a total number of 9 conditioning parameters being involved in the occurrence of the landslide events were determined and utilized. The LSM maps of the TB were generated based on the different SVM kernels and were statistically validated according to the landslide inventory. The findings revealed that the polynomial-degree-2 (PKF-2) model (AUC = 0.9688) outperforms the rest of the utilized kernels. According to the SLM map generated through PKF-2, the northernmost parts of the TB are extremely susceptible to slope failures than the rest; therefore, the developmental policies over these parts have to be taken into account with privileged priority to hinder any humanitarian as well as environmental catastrophes.
... The latter is especially important since landslides are often triggered by precipitations and the resulting change in the groundwater level. Water reduces ground strength and increases pore pressures, contributing to the instability of a slope [7,[10][11][12][13]. Controlling the water table is essential when dealing with shallow and slow movements, as any rainfall may accelerate or even reactivate a landslide. ...
This case study presents the engineering approach conducted for stabilizing a landslide that occurred at “El Portalet” Pass in the Central Spanish Pyrenees activated due to the construction of a parking lot. Unlike common slope stabilization cases, measures projected here were aimed at slowing and controlling the landslide, and not completely stopping the movement. This decision was taken due to the slow movement of the landslide and the large unstable mass involved. The degree of success of the stabilization measures was assessed by stability analyses and data obtained from different geotechnical investigations and satellite survey techniques such as GB-SAR and DinSAR conducted by different authors in the area under study. The water table was found to be a critical factor in the landslide’s stability, and the tendency of the unstable slope for null movement (total stability) was related to the water table lowering process, which needs more than 10 years to occur due to regional and climatic issues. Results showed a good performance of the stabilization measures to control the landslide, demonstrating the effectiveness of the approach followed, and which became an example of a good response to the classical engineering duality cost–safety.
... Most studies have demonstrated that the mechanism of weakening by fluid is an important trigger in landslides. To further our understanding of the mechanisms behind landslides, geophysical, geotechnical, and geodetic monitoring approaches, including electrical resistivity tomography (ERT) [8], active seismic exploration, borehole drilling [9,10], downhole monitoring of displacement and water level [11,12], and GPS-based surface movement [13,14], have been applied not only to clarify the geometry and geological structures involved but also to ascertain the depth of the multiple sliding interfaces located beneath deep-seated landslides. However, some limitations have led to the poor understanding of landslides: (1) Geophysical profiles, such as active seismic imaging, are usually limited to tens of meters of depth due to the insufficient power of the active source and the complex topography changes in mountain area, (2) only few point-based investigations of surface movement and few borehole drillings have been conducted due to high cost and invasiveness. ...
Landslides have caused extensive infrastructure damage and caused human fatalities for centuries. Intense precipitation and large earthquakes are considered to be two major landslide triggers, particularly in the case of catastrophic landslides. The most widely accepted mechanistic explanation for landslides is the effective-stress dependent shear strength reduction due to increases in pore water pressure. The Chashan landslide site, selected for the present study, has been intensively studied from geological, geophysical, geodetic, geotechnical, hydrological, and seismological perspectives. Our seismic monitoring of daily relative velocity changes (dv/v) indicated that landslide material decreases coincided with the first half of the rainy period and increased during the latter half of the rainy period. The geodetic surveys before and after the rainy period identified vertical subsidence without horizontal movement. The results from the multidisciplinary investigation enabled us to draw a conceptual model of the landslide recovery process induced by water loading. Where all sliding materials were stable (safety factor > 1.0), unconsolidated landslide colluvium and impermeable sliding surfaces trapped the seepage water to form a water tank, provided that compact forces were acting on the materials below the sliding boundary. The vertical force of compaction facilitates an increase in the cohesion and strength of landslide materials, thereby increasing the landslide materials’ stability. We demonstrated that the recovery process periodically occurs only under the combined conditions of prolonged and intense precipitation and the related stability conditions.
... At present, many studies on the instability mechanism of rock slopes are conducted (Gibson et al. 2018;Yuan et al. 2020b;Meng et al. 2018;Chen et al. 2021), except for the commonly used rigid limit equilibrium method (Jafarzadeh et al. 2019;Jiang et al. 2018) and strength reduction method Yuan et al. 2020a;Yin et al. 2020;Chen et al. 2020). Several scholars elaborated the instability mechanism of rock slopes (Herrera et al. 2009) and momentum equations (Corominas et al. 2005). However, most of the applications of these theories are based on the assumption that the sliding surface of the slope is connected, and the geological structure of the locked section is ignored. ...
The locked section is a kind of geological structure that is commonly found in natural slopes. The instability criterion of the slope with a locked section structure is not yet studied. In accordance with the mechanical properties of this type of slope, the rock mass is divided into several rock blocks along its joint distribution, and the upper limit method of plastic limit analysis is introduced. By combining the principle of virtual work and the characteristics of the slope, a virtual speed is assigned to the slope and the locked section. In addition, the maximum elastic strain energy that can be accumulated in the locked section is calculated to derive its deformation rate and internal energy dissipation power. The virtual velocity, internal energy dissipation power, and gravity work power of the locked section and the rock slope are solved simultaneously in accordance with the Mohr–Coulomb correlation flow law. Finally, the formula for calculating the safety factor of this type of slope under shear failure mode is derived. A slope in Xikou, Sichuan, China, is taken as an example to verify the proposed model.
... The integration between these two-monitoring systems has been tested and evaluated in the village of Pariana (Massa, Italy). The usefulness of the proposed monitoring system can be improved by integrating it with analytical methods to perform a prediction of the mobility of rainfall-induced landslides [33][34][35]. ...
Slow to extremely slow landslides in urban areas may cause severe damage to buildings and infrastructure that can lead to the evacuation of local populations in case of slope accelerations. Monitoring the spatial and temporal evolution of this type of natural hazard represents a major concern for the public authorities in charge of risk management. Pariana, a village with 400 residents located in the Apuan Alps (Massa, Tuscany, Italy), is an example of urban settlement where the population has long been forced to live with considerable slope instability. In the last 30 years, due to the slope movements associated with a slow-moving landslide that has affected a significant portion of the built-up area, several buildings have been damaged, including a school and the provincial road crossing the unstable area, leading to the need for an installation of a slope monitoring system with early warning capabilities, in parallel with the implementation of mitigation works. In this paper, we show how satellite multi-temporal interferometric synthetic aperture radar (MT-InSAR) data can be effectively used when coupled with a wireless sensor network made of several bar extensometers and a borehole inclinometer. In fact, thanks to their wide area coverage and opportunistic nature, satellite InSAR data allow one to clearly identify the spatial distribution of surface movements and their long-term temporal evolution. On the other hand, geotechnical sensors installed on specific elements at risk (e.g., private buildings, retaining walls, etc.), and collected through Wi-Fi dataloggers, provide near real-time data that can be used to identify sudden accelerations in slope movements, subsequently triggering alarms. The integration of those two-monitoring systems has been tested and assessed in Pariana. Results show how a hybrid slope monitoring program based on the two different technologies can be used to effectively monitor slow-moving landslides and to identify sudden accelerations and activate a response plan.
... Similarly, for anticipation/estimation of the hazards associated with landslide, a physics-based dynamical model, This work is supported by the French National Research Agency in the framework of the Investissements dAvenir program (ANR-15-IDEX-02) landslide monitoring, and heterogeneous data handling play a vital role. These physics-based dynamical models, e.g., sliding-consolidation model (Hutchinson, 1986), viscoplastic sliding-consolidation model (Corominas et al., 2005;Herrera et al., 2013;Bernardie et al., 2014) and extended sliding-consolidation model (Iverson, 2005) are sensitive to the initial conditions and parameters of the system. These sensitivities can be taken into account by simulating a model and iteratively adjusting the initial conditions and parameter values to obtain consistency with measured data, i.e., by adjoint method (Nguyen et al., 2016). ...
This paper presents an observer-based state and parameter estimation for the extended sliding-consolidation model of a landslide. This system is described by a pair of coupled Ordinary Differential Equation (ODE) and Partial Differential Equation (PDE), with a mixed boundary condition for the PDE. The coupling appears both in the ODE and in the Neuman boundary condition of the PDE. The observer consists of a copy of the PDE part of the system and Kalman-like observer for the ODE. It is shown to ensure exponential convergence of the state and parameter estimates by means of Lyapunov tool. Finally, a simulation result of the extended sliding-consolidation model is presented to illustrate the effectiveness of the proposed observer.
As part of the water cycle, groundwater is a major contributor to flow in rivers and has a strong influence on landslide. This paper proposes a landslide early warning system for detecting landslide. Our aim is to analyze the groundwater flow by conducting laboratory test in Politeknik Negeri Semarang, Semarang City on groundwater flow detectors’ sensors accuracy on rainfall, water level and soil moisture content. We undertook this research by employing LoRa and testing the performance of sensors on groundwater flow using a rainfall sensor, a soil moisture content detector using a capacitive soil moisture sensor, and the water level detector using the VL53l0X sensor and tested using a permeability tank. We used Muntilan sand which is categorized as well-graded sand in our experiment. The results of rainfall sensor test resulted in an effluent value of 0.053 inch or 1.346 mm of water, while the water level sensor produced an average error of 0.02667 for object distance testing, and for soil moisture sensors in dry sand, it produced ADC 2.94 V while wet sand results in 2.084 V. We conclude that the accuracy of rainfall and water level are good, while for soil moisture content is bad due to sensor’s sensitivity since the operating voltage is 3.3 ~ 5.5 VDC.
Slow-moving landslides affect proximal infrastructures and communities, often causing extensive economic loss. While many of these landslides exhibit slow and episodic sliding for decades or more, they sometimes accelerate rapidly and fail catastrophically. Although it is known that the landslide dynamics are controlled by hydro-mechanical processes, few analytical models enable a versatile incorporation of the inelastic behavior of the shear zone materials, thus hindering an accurate quantification of how their properties modulate the magnitude and rate of coupled fluid flow and landslide motion. To address this problem, we develop a simulation framework incorporating rainfall-induced, deformation-mediated pore-water pressure transients at the base of active landslides. The framework involves the computation of two sequential diffusion processes, one within an upper rigid-porous landslide block, and another within the inelastic shear zone. Although the framework can be linked to any elastoplastic constitutive laws, here we model landslide motion through an elastic-perfectly plastic frictional model, which enables us to account for standard properties of earthen materials such as elastic moduli, friction angle, dilation angle, and hydraulic conductivity. Numerical case studies relevant to slow-moving landslides in the California Coast Ranges show that the proposed formulation captures different temporal patterns of movement induced by precipitation. In each of the case, we achieved a relatively accurate match between data and simulations by incorporating positive dilation coefficients, which leads to spontaneous generation of negative excess pore-water pressure and self-regulating motion. Conversely, simulations with no dilation (hence, reflecting the approach of critical state) produce sharp acceleration, typical of catastrophic runaway acceleration. Our findings encourage the use of the proposed framework in conjunction with constitutive laws tailored to site-specific geomaterial properties and data availability, thus favoring a versatile representation of the variety of creeping landslide trends observed in nature.
Slow‐moving deep‐seated landslides are characterized 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 capable 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 the slope’s stability. Additionally, scenarios of past and future topographies were reconstructed and projected. Mass relocations in the order of 25 000m3 were assessed between multiple airborne laser scanning (ALS) acquisitions covering a period of 13 years. Based on annual uncrewed aerial vehicle laser scanning (ULS) campaigns area‐wide 3Ddisplacements 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 the slope’s stability and therefore modify the spatio‐temporal activity of the landslide. It is shown, that besides the hydro‐meteorological 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.
Motivated by some landslide models, and related estimation challenges, this paper presents an optimal estimation method for state and parameter in a special class of co-called ODE-PDE system based on the adjoint method for discrete-time asynchronous measurements. This system is described by a pair of coupled Ordinary Differential Equation (ODE) and Partial Differential Equation (PDE), with a mixed boundary condition for the PDE. The coupling appears both in the ODE and in the Neuman boundary condition of the PDE. For this system, initial conditions or state variables and some empirical parameters are assumed to be unknown and need to be estimated. The Lagrangian multiplier method is used to connect the dynamics of the system and the cost function defined as the least square error between the simulation values and the available measurements. The adjoint state method is applied to the objective functional to get the adjoint system and the gradients with respect to parameters and initial state. The cost functional is optimized, employing the steepest descent method to estimate parameters and initial state. This general approach is illustrated by two application examples corresponding to two different landslide models that validate the presented optimal estimation approach. The first one is about state and parameter estimation in an extended sliding-consolidation landslide model, and the second one is in the viscoplastic sliding-consolidation landslide model.
In mountain areas, anthropic pressure is growing while, concurrently, landslide frequency in most of the mountain regions of the world is increasing due to a more extreme precipitation pattern and permafrost deglaciation. Because of budget constraints, the need to investigate innovative and low-cost countermeasures for landslide risk is becoming more and more pressing. In this context, the Passo della Morte area (North-East Italy) is a perfect benchmark case. It comprises an extensive, long-term database of monitoring data that allows for testing hypotheses and validating them. Based on this data, a strong correlation between the velocity of a displacement of a landslide and the discharge of the Rio Verde stream was found. According to this evidence, local authorities have started the construction of a completely innovative mitigation strategy. It is focused on the triggering factor by identifying a significant component of the flow rate of the stream that cuts through the landslide. In addition, aiming to reduce the cost of construction and maintenance, this mitigation strategy is coupled with a micro-hydropower plant that can provide economic revenue by exploiting the discharge itself to produce electricity. Considering the active monitoring system that will be used to verify the effectiveness of the countermeasure, the Passo della Morte case study could become a starting point for implementing this pioneering and low-cost mitigation solution in similar morphologies.
Landslides are one of the major weather related geohazards. To assess their potential impact and design mitigation solutions, a detailed understanding of the slope processes is required. Landslide modelling is typically based on data-rich geomechanical models. Recently, machine learning has shown promising results in modelling a variety of processes. Furthermore, slope conditions are now also monitored from space, in wide-area repeat surveys from satellites. In the present study we tested if use of machine learning, combined with readily-available remote sensing data, allows us to build a deformation nowcasting model. A successful landslide deformation nowcast, based on remote sensing data and machine learning, would demonstrate effective understanding of the slope processes, even in the absence of physical modelling. We tested our methodology on the Vögelsberg, a deep-seated landslide near Innsbruck, Austria. Our results show that the formulation of such machine learning system is not as straightforward as often hoped for. Primary issue is the freedom of the model compared to the number of acceleration events in the time series available for training, as well as inherent limitations of the standard quality metrics. Satellite remote sensing has the potential to provide longer time series, over wide areas. However, although longer time series of deformation and slope conditions are clearly beneficial for machine learning based analyses, the present study shows the importance of the training data quality but also that this technique is mostly applicable to the well-monitored, more dynamic deforming landslides.
This paper intends to introduce a novel groundwater prediction model by inducing the novel hydro indices that are not yet popular in earlier techniques. As per the proposed work, statistical features like mean, median, skewness and kurtosis are estimated. Moreover, the vegetation index includes simple ratio, normalized difference vegetation index, Kauth–Thomas Tasseled cap transformation and infrared index transformation. Furthermore, a novel hydro index is formulated by combining the statistical model function with the vegetation index. Subsequently, the detection process is carried out by ensemble technique, which includes the classifiers like random forest (RF), neural network (NN), support vector machine (SVM) and deep belief network (DBN). The final predicted result is attained from DBN. The performance of the adopted model is computed to the existing models with respect to certain measures. At learning rate 50, the maximum accuracy of the proposed model is 45.65, 34.78, 58.70, 72.83, 18.48 and 23.91% better than the existing models like SVM, RF, convolutional neural network, K-nearest neighbors, NN and artificial neural network, respectively.
The landslide comes as the rehashed geographical dangers in the blustery season, which brings fatal damages, harmful to property, what's more, monetary misfortunes. Landslides are in charge of in any event 17% of all fatalities from normal perils around the world, and almost 25% of yearly losses brought about by regular dangers. Because of worldwide environmental change, the recurrence of a landslide event has been expanded and, in this way, the misfortunes and harms related to landslides likewise have been expanded. Consequently, the exact forecast of landslide event, and observing and advance cautioning for ground needs to be done. Developments are significant errands to diminish the harms and misfortunes brought about via landslides. Landslide is turning into an issue all through the world. The recurrence and greatness of landslides undermining an enormous populace and the condition is expanding over the world. Remote detecting framework is playing an imperative job in Landslide forecast. In explicit, satellite remote detecting is powerful in covering a huge territory for catching pictures, which thusly is utilized as a contribution for preparing the framework for foreseeing landslides before about fourteen days utilizing the neural systems.KeywordsRelocation expectationGated recurrent unitLandslide observingEarly cautioningDeep learning
Knowledge of landslide displacement trends is important to understand risks and establish early warning trigger thresholds so that action can be taken to protect people and critical infrastructure. However, the availability of direct continuous displacement measurements is often limited due to relatively high costs. This has driven research to establish models that quantify relationships between landslide displacements and other measured parameters such as pore water pressures, rainfall and more recently acoustic emission (AE), so that displacement can be predicted, and hence made available at a lower cost. This paper describes an investigation of established machine learning models to predict displacements using time series measurements of AE and rainfall. Data from a case study site has been used to train models using measured displacements and then test to assess prediction accuracy. The LASSO-ELM model was shown to perform best. It was able to predict displacements to a mean absolute percentage error < 2.5% up to 60 days after the end of the training period, which is better than similar reported studies. Training a LASSO-ELM model using continuous high resolution AE measurements combined with rainfall data has potential to provide predicted displacement trends once direct measurement of displacement is no-longer available.
In the present study, the landslides cyclically reactivated by water-table oscillations due to rainfall are dealt with. The principal kind of motion that usually characterizes such landslides is a slide with rather small velocity. As another feature, soil deformations are substantially accumulated inside a narrow shear zone situated below the landslide body so that the latter approximately slides rigidly. Within this framework, a new approach is developed in this paper to predict the mobility of this type of landslides due to rainfall. To this end, a two-wedges model is used to schematize the moving soil mass. Some analytical solutions are derived to link rain recordings with water-table fluctuations and in turn to landslide displacements. A well-documented landslide frequently activated by rainfall is studied to check the forecasting capacity of the proposed method.
This paper describes a visco-plastic model which, using recorded groundwater levels, is capable of simulating the velocity trend in landslides. It also deals with the phenomenon of shear strength regain that occurs in montmorillonitic clays constituting slopes during periods when landslides are stationary. The model has been validated with long-term observations of a clay slope affected by a mudslide.
The majority of slope stability analyses performed in practice still use traditional limit equilibrium approaches involving methods of slices that have remained essentially unchanged for decades, This was not the outcome envisaged when Whitman & Bailey (1967) set criteria for the then emerging methods to become readily accessible to all engineers, The finite element method represents a powerful alternative approach for slope stability analysis which is accurate, versatile and requires fewer a priori assumptions, especially, regarding the failure mechanism, Slope failure in the finite element model occurs 'naturally' through the zones in which the shear strength of the soil is insufficient to resist the shear stresses. The paper describes several examples of finite element slope stability analysis with comparison against other solution methods, including the influence of a free surface on slope and dam stability. Graphical output is included to illustrate deformations and mechanisms of failure. It is argued that the finite element method of slope stability analysis is a more powerful alternative to traditional limit equilibrium methods and its widespread use should now be standard in geotechnical practice.
Major pit slope movements on rock mass discontinuities were initiated by an earthquake in December 1967 and sustained by excavation and blasting operations. Limiting equilibrium analysis suggests that average cohesion mobilized in the slope movements was low (ca. 100 kN/m2) and that friction was also low (Φ = 20–25°). Fluid pressures were apparently absent. The low strength values suggest that failure occurred on smooth joint surfaces coated with sheet silicate minerals. These surfaces are interpreted from analysis and are apparently not reflected in available statistical analyses of rock fabric. The portion of the slope which ultimately collapsed involved three relatively distinct blocks separated by major discontinuities; sliding occurred on planes dipping at perhaps 23–37°W. Displacement and acoustic emission data were collected over a period of a year following initial observations of slope movement. Extrapolation of displacement data was used to predict slope collapse over a month in advance of the date of actual collapse in 1969. Advance prediction permitted modification of mine transportation systems, and mine production was stopped for only 65 hours. No injuries or equipment damage occurred.
The majority of slope stability analyses performed in practice still use traditional limit equilibrium approaches involving methods of slices that have remained essentially unchanged for decades. This was not the outcome envisaged when Whitman & Bailey (1967) set criteria for the then emerging methods to become readily accessible to all engineers. The finite element method represents a powerful alternative approach for slope stability analysis which is accurate, versatile and requires fewer a priori assumptions, especially, regarding the failure mechanism. Slope failure in the finite element model occurs `naturally' through the zones in which the shear strength of the soil is insufficient to resist the shear stresses. The paper describes several examples of finite element slope stability analysis with comparison against other solution methods, including the influence of a free surface on slope and dam stability. Graphical output is included to illustrate deformations and mechanisms of failure. It is argued that the finite element method of slope stability analysis is a more powerful alternative to traditional limit equilibrium methods and its widespread use should now be standard in geotechnical practice.
This paper describes a visco-plastic model which, using recorded groundwater levels, is capable of simulating the velocity trend in landslides. It also deals with the phenomenon of shear strength regain that occurs in montmorillonitic clays constituting slopes during periods when landslides are stationary. The model has been validated with long-term observations of a clay slope affected by a mudslide.
A continuous recording of landslide displacements is often required in order to better understand the complex relationship between the triggering factors and the dynamics of the movement. In this paper, we discuss the performance of the borehole wire extensometer and the interpretation of its results. The analysis for the case of a translational slide shows that the displacements measured with the wire extensometer are systematically smaller than the movements observed at the ground surface. A relationship between the wire readings and the horizontal component of the landslide movement has been established by means of three equations representing different stages of the wire displacement within the borehole. The applicability of these equations and the interpretation of the wire extensometer readings have been successfully checked at two landslide sites: Vallcebre in the eastern Pyrenees and Alverà in the Dolomites.
A real-time system for issuing warnings of landslides during major storms is being developed for the San Francisco Bay region, California. The system is based on empirical and theoretical relations between rainfall and landslide initiation, geologic determination of areas susceptible to landslides, real-time monitoring of a regional network of telemetering rain gages, and National Weather Service precipitation forecasts. This system was used to issue warnings during the storms of 12 to 21 February 1986, which produced 800 millimeters of rainfall in the region. Although analysis after the storms suggests that modifications and additional development are needed, the system successfully predicted the times of major landslide events. It could be used as a prototype for systems in other landslide-prone regions.
Rainfall intensity and duration of storms has been shown to influence the triggering of debris flows. After examining storm records of the San Francisco Bay region, documenting when debris flows occurred, and measuring piezometric levels in shallow hillside soils, continuous high-intensity rainfall was found to play a key role in building pore-water pressures that trigger debris flows. Debris flows in 10 storms between 1975 and 1984 in a 10-km2 area near La Honda, California, were examined, and their rainfall records compared to the records of other storms to determine the antecedent conditions and the levels of continuous, highintensity rainfall necessary for triggering debris flows. No flows were triggered before 28 cm of rainfall had accumulated each season, which suggests that prestorm soilmoisture conditions are important. After this sufficient antecedent rainfall, a threshold of rainfall duration and intensity-which accounted for triggering at least one debris flow per storm within the study area-was identified. The number of debris flows increased in storms with intensity and duration characteristics significantly above this threshold. By studying where debris flows initiated in storms of different intensity and duration, debris flow susceptibility was found to depend on soil thickness and hillside concavity and steepness. Moderate intensity storms of long duration triggered complex soil slump/debris flows in thick soils on concave slopes below large drainage areas, whereas high-intensity storms of short duration caused complex soil slide/debris flows in thinner soils without respect to size of drainage area. From these observations, an empirical model based on geology, hydrology, and topography is proposed to account for the triggering of debris flows at selective sites by storms with different combinations of intensity and duration once the antecedent and intensity-duration thresholds are exceeded.
Landslides are triggered by factors such as heavy rainfall, seismic activity, and construction on hill-slopes. The leading cause of landslides in Puerto Rico is intense and/or prolonged rainfall. A rainfall threshold for rainfall-triggered landsliding is delimited by 256 storms that occurred between 1959 and 1991 in the central mountains of Puerto Rico, where mean annual rainfall is close to or in excess of 2,000 mm. Forty one of the 256 storms produced intense and/or prolonged rainfall that resulted in tens to hundreds of landslides. A threshold fitted to the lower boundary of the field defined by landslide-triggering storms is expressed as I = 91.46 D-0.82 where I is rainfall intensity in millimeters per hour, and D is duration in hours. Landslide-producing storms occurred at an average rate of 1.2 per year. In general the landslides triggered by short-duration, high-intensity rainfall events were mainly shallow soil slips and debris flows, while the long-duration, low-intensity rainfall produced larger, deeper debris avalanches and slumps. For storms that had durations of up to 10 h, landsliding did not occur until rainfall intensity was as much as three times as high as the rainfall intensity reported as sufficient to trigger landsliding in temperate regions. As storm durations approach 100 h, the rainfall conditions necessary to initiate landsliding in Puerto Rico converge with those defined for temperate regions. A comparison of the Puerto Rico threshold with rainfall data from other humid-tropical regions suggests that the threshold developed for Puerto Rico may be applicable to other similar environments throughout the world.
Published records of the rainfall intensities and durations associated with shallow landsliding and debris flow activity suggests a limiting threshold for this type of slope instability. The limit has the general form: I = 14.82 D-0.39 and is best defined for rainfall durations between 10 minutes and 10 days.
A shear strength reduction technique for finite element slope stabilityan alysis has been developed by the authors. An important orginal point in the proposed method is that the slope failure is defined according to the shear strain failure criterion. The aim of this paper is to verify the shear strength reduction technique for the finite element slope stability analysis. Are presented the detailed background behind the shear strength reduction technique, the elucidation of the physical meaning of the critical shear strength reduction ratio in regard to the total shear strain and shear strain increment for both embankment and excavation slopes and its practical application to a field test on a reinforced slope cutting.
As the results, the critical shear strength reduction ratio agrees with the safety factor by the Bishop’s method if total shear strain is used for analyses of embankment slopes. In the case of the natural excavation slopes, in which total shear strain is difficult to be assessed, the safety factor can be related to the average of the local safety factors along the failure slip surface obtained by the shear strength reduction technique. The predicted behavior of the reinforced slope cutting agrees with the field test data and site observation. Agreement between the shear strength reduction technique and a modified Fellenius’ method is satisfactory. Consequently, applicability of the proposed method to practical design works is demonstrated.
On the basis of measurements of hydrological parameters and field monitoring of a landslide in the Terres Noires in the basin of Barcelonnette (France), a hydrological model was developed, describing groundwater fluctuations in relation to precipitation. These groundwater fluctuations can be used as input to a stability model in order to assess the temporal frequency of instability of the landslide. The calculated groundwater fluctuations, which can forecast years with landslide incidents, were roughly calibrated against dated movements obtained by dendrochronological research. The hydrological system of the landslide can be understood through a three-layer sequence: a rather permeable colluvial top layer underlain by a less permeable colluvial second layer, both overlying the nearly impermeable in situ non- weathered black marls (Terres Noires). The mean Ksat value for the matrix flow in the top layer is 15·7 cm/day and in the underlying layer 0·7 cm/day. However, water fluxes in these layers occur by two types of groundwater flow: matrix flow obeying Darcy's law, and more rapid gravitational flow through preferential flow paths, increasing the conductivity by a factor of 10 to 100, as cube method Ksat measurements revealed. The model shows long-term yearly fluctuations of the phreatic surface, with peaks at the end of winter, as well as at the beginning of spring, and minimum values during the dry summer period. These long-term fluctuations are explained by the high drainage capacity of the top colluvial layer and the relatively low vertical water fluxes within the underlying colluvial layer. The model shows that maximum critical peak height conditions of the groundwater, causing instability, occur in wet seasons, with at least six consecutive months with high amounts (more than 60 mm) of precipitation. © 1997 by John Wiley & Sons, Ltd.
A global database of 2,626 rainfall events that have resulted in shallow landslides and debris flows was compiled through
a thorough literature search. The rainfall and landslide information was used to update the dependency of the minimum level
of rainfall duration and intensity likely to result in shallow landslides and debris flows established by Nel Caine in 1980.
The rainfall intensity–duration (ID) values were plotted in logarithmic coordinates, and it was established that with increased
rainfall duration, the minimum average intensity likely to trigger shallow slope failures decreases linearly, in the range
of durations from 10min to 35days. The minimum ID for the possible initiation of shallow landslides and debris flows was
determined. The threshold curve was obtained from the rainfall data using an objective statistical technique. To cope with
differences in the intensity and duration of rainfall likely to result in shallow slope failures in different climatic regions,
the rainfall information was normalized to the mean annual precipitation and the rainy-day normal. Climate information was
obtained from the global climate dataset compiled by the Climate Research Unit of the East Anglia University. The obtained
global ID thresholds are significantly lower than the threshold proposed by Caine (Geogr Ann A 62:23–27, 1980), and lower than other global thresholds proposed in the literature. The new global ID thresholds can be used in a worldwide
operational landslide warning system based on global precipitation measurements where local and regional thresholds are not
available..
The precise determination of point coordinates with conventional Global Positioning System (GPS) techniques often required observation times of one to several hours. In the last few years, new GPS methods have been developed (among them, the fast-static and real time kinematic), with higher productivity and good theoretical precision. The main objective of this paper is to ascertain the performance of these methods in landslide monitoring practice. We present, first of all, the basic principles of the GPS, the equipment and working procedures. We discuss afterwards the applicability of the GPS to the monitoring of landslide surface displacements. Compared with the classical surveying methods, the GPS allows a larger coverage and productivity with similar accuracy. Furthermore, it can work in all kinds of weather conditions and a direct line of sight between stations is not required. Finally, we present an example of the performance of the GPS equipment in the landslide of Vallcebre, Eastern Pyrenees (Spain). This landslide has been periodically monitored since 1987 with terrestrial photogrammetry and geodetic measurements [theodolite, electronic distance metres (EDM)]. The movement extends over an area of 0.8 km2 and has experienced displacements as large as 1.6 m during the period 1996–1997. 14 campaigns, over a period of 26 months, using both static and kinematic GPS methods have been carried out. The GPS measurements have been compared with the results obtained with the EDM, inclinometers and wire extensometers, and checked against fixed stable points. The precision achieved with the GPS measurements is 12 to 16 mm in the horizontal plane and 18 to 24 mm in elevation.
This paper describes an extension to the Combined Hydrology And Stability Model (CHASM) to fully include the effects of vegetation and slope plan topography on slope stability. The resultant physically based numerical model is designed to be applied to site-specific slopes in which a detailed assessment of unsaturated and saturated hydrology is required in relation to vegetation, topography and slope stability. Applications are made to the Hawke's Bay region in New Zealand where shallow-seated instability is strongly associated with spatial and temporal trends in vegetation cover types, and the Mid-Levels region in Hong Kong, an area subject to a variety of landslide mechanisms, some of which may be subject to strong topographic control. An improved understanding of process mechanism, afforded by the model, is critical for reliable and appropriate design of slope stabilization and remedial measures. Copyright © 2002 John Wiley & Sons, Ltd.
Results are presented of a sequence of laboratory tests undertaken to elucidate the behaviour of deep-seated landslides. In deep-seated failures deformation has been reported at depths of up to 250 m. In the movement zone, owing to the weight of the overburden and the surrounding stress environment, conventional soil mechanics cannot be used to explain effectively associations between the landslip activity and the deformation mechanisms operating within the moving mass. A series of experiments has been undertaken on London Clay using a high pressure, servohydraulically controlled triaxial deformation system, to replicate the stresses acting at the base of a large, deep-seated landslide. A number of tests were undertaken, the most significant focusing on the transition between ductile and brittle behaviour. Although sediments usually behave in a brittle manner at low effective stresses (common to many geomorphological studies) and in a ductile manner at high effective stresses, the results presented here identify for the first time in mudrocks a transitional phase of behaviour in which creep-like movement will manifest itself at the base of a deep-seated landslide as the growth of microcracks. The microcracks may eventually coalesce to form a shear surface, a consequence of which is likely to be sudden failure. The results thus have important implications in the understanding of movement mechanisms in large, deep-seated failures, rates of displacement and how they may change through time. © 1997 by John Wiley & Sons, Ltd.
Research into the climatic causes behind the triggering and reactivation of landslides has been carried out in two basins in the Southern French Alps, where a great many landslides have occurred over more than a century. Correlations between landslides and climate are sometimes precise and closely related in time, at other times imprecise and more distant. The better known the type of landslide and the date of its occurrence, the greater the correlation may appear. Be this as it may, climate is never the sole cause. This paper deals with the limits of the effects of climate.
The movement of rotational and translational landslides occurs as a result of either sliding on discrete shear surfaces or ductile deformation within a shear zone. In this paper we examine the movement histories of a number of landslides that occurred in a variety of materials in a range of settings, and demonstrate that one of two movement styles is evident during accelerating phases for all landslides observed. The first style, which has previously been noted, has a linear form in a plot of 1/v against time (v is velocity). The second style has an asymptotic form in the same plot, trending toward steady-state movement rates. We propose that the linear form occurs in landslides in which crack propagation (i.e., shear surface generation) is the dominant process, whereas the second style occurs where movement is taking place across existing planes of weakness or as a result of ductile deformation processes. This study demonstrates that the evaluation of plots of 1/v against time for landslides is a useful technique for forecasting movement styles and rates, and for interpreting ongoing deformation processes in real time
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Landslides on soil debris cover triggered by rainstorm in Valtellina (Central Alps, Italy)
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Landslides on soil debris cover triggered by rainstorm in Valtellina
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Fernandez-Pombo MP (1998) Esllavissada de Vallcebre. Condicions d'equilibri límit del vessant i
estudi sobre el comportament viscoplàstic del moviment. Graduation Project. Civil Engineering
School, Barcelona. Unpublished
Flageollet JC, Maquaire O, Martin B, Weber D (1999) Landslides and climatic conditions in the
Barcelonnette and Vars basins (Southern French Alps, France). Geomorphology 30:65-78