Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change

Abstract. Landslides have large negative economic and societal impacts, including loss of life and damage to infrastructure. Slope stability assessment is a vital tool for landslide risk management, but high levels of uncertainty often challenge its usefulness. Uncertainties are associated with the numerical model used to assess slope stability and its parameters, with the data characterizing the geometric, geotechnic and hydrologic properties of the slope, and with hazard triggers (e.g. rainfall). Uncertainties associated with many of these factors are also likely to be exacerbated further by future climatic and socio-economic changes, such as increased urbanization and resultant land use change. In this study, we illustrate how numerical models can be used to explore the uncertain factors that influence potential future landslide hazard using a bottom-up strategy. Specifically, we link the Combined Hydrology And Stability Model (CHASM) with sensitivity analysis and Classification And Regression Trees (CART) to identify critical thresholds in slope properties and climatic (rainfall) drivers that lead to slope failure. We apply our approach to a slope in the Caribbean, an area that is naturally susceptible to landslides due to a combination of high rainfall rates, steep slopes, and highly weathered residual soils. For this particular slope, we find that uncertainties regarding some slope properties (namely thickness and effective cohesion of topsoil) are as important as the uncertainties related to future rainfall conditions. Furthermore, we show that 89 % of the expected behaviour of the studied slope can be characterized based on only two variables – the ratio of topsoil thickness to cohesion and the ratio of rainfall intensity to duration.

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Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change

10.5194/nhess-2016-278 ◽

2016 ◽

Author(s):

Susana Almeida ◽

Elizabeth Holcombe ◽

Francesca Pianosi ◽

Thorsten Wagener

Keyword(s):

Slope Stability ◽

Slope Failure ◽

Numerical Models ◽

Landslide Risk ◽

Residual Soils ◽

Soil Thickness ◽

Economic Changes ◽

Critical Thresholds ◽

Top Soil ◽

Steep Slopes

Abstract. Landslides have large negative economic and societal impacts, including loss of life and damage to infrastructure. Slope stability assessment is a vital tool for landslide risk management, but high levels of uncertainty often challenge its usefulness. Uncertainties are associated with the numerical model used to assess slope stability and its parameters, with the data characterising the geometric, geotechnic and hydrologic properties of the slope, and with hazard triggers (e.g., rainfall). Uncertainties associated with many of these factors are also likely to be exacerbated further by future climatic and socio-economic changes, such as increased urbanisation and resultant land use change. In this study, we illustrate how numerical models can be used to explore the uncertain factors that influence potential future landslide hazard using a bottom-up strategy. Specifically, we link the Combined Hydrology And Stability Model (CHASM) with sensitivity analysis and Classification And Regression Trees (CART) to identify critical thresholds in slope properties and climatic (rainfall) drivers that lead to slope failure. We apply our approach to a slope in the Caribbean, an area that is naturally susceptible to landslides due to a combination of high rainfall rates, steep slopes, and highly weathered residual soils. For this particular slope, we find that uncertainties regarding some slope properties (namely thickness and effective cohesion of top soil) are as important as the uncertainties related to future rainfall conditions. Furthermore, we show that 89 % of the expected behaviour of the studied slope can be characterised based on only two variables – the ratio of top soil thickness to cohesion and the ratio of rainfall intensity to duration.

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Experimental Study on Slope Stability with Soil Mixed Rocks under Rainfall

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.506 ◽

2012 ◽

Vol 170-173 ◽

pp. 506-510

Author(s):

Fang Cai Zhu ◽

Yue Yang ◽

Chun Ming Chen

Keyword(s):

Experimental Study ◽

Slope Stability ◽

Water Content ◽

Slope Failure ◽

Western China ◽

Laboratory Model ◽

Small Scale ◽

Loss Of Life ◽

Key Factor ◽

Scale Failure

Rainfall is a key factor that triggers failure of slopes. Due to development of western China, there are more and more slopes with soils mixed rocks, with rainfall effect, some of them will fail, which will lead to loss of life and property. In this paper, a laboratory model was used to simulate to study slope failure of this type under rainfall. Along with rainfall, water infiltrated into the slope, and water content increased steadily and kept almost constant, settlement of inner zone increased with different magnitude and reached almost constant value, and cracks formed on the top, small scale failure occurred.

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Performance Evaluation of Geometric Modification on the Stability of Road Cut Slope Using FE Based Plaxis Software

10.5772/intechopen.99633 ◽

2021 ◽

Author(s):

Fentahun Ayalneh Mekonnen

Keyword(s):

Performance Evaluation ◽

Slope Stability ◽

Slope Failure ◽

Human Life ◽

Slope Angle ◽

Cut Slope ◽

Governing Parameter ◽

Stability Of Slope ◽

The Stability ◽

Steep Slopes

Slope failures are among the common geo-environmental natural hazards in the hilly and mountainous terrain of the world. Specially it is the major difficulty for the development of construction as it causes considerable damage on the infrastructure, human life and property. Different causes of slope failure and stabilization methods are proposed by different scholars. In this study the performance of geometric modification in slope stability was investigated using numerical method. The study uses slope height, slope angle and slope profile i.e. single slope, multi slope and bench slope as a governing parameter in the performance evaluation of geometric modification on the slope stability. The evaluation was conducted on a newly constructed road cut slope using a finite element based plaxis software. The result from performance evaluation of slope profiles show that geometric modification provides better and economical slope stability. The stability of slope decreases with increase in slope height and slope angle leading to an uneconomical design of high slopes in a single slope profile. However, the use of benching improves the stability of cut slope (i.e. the use of 2 m and 3 m bench improves the factor of safety by 7.5% and 12% from single slope profile). The method is more effective in steep slopes. Similarly, the use of a multi slope profile improves the stability of slope in stratified soil with varied strength. The performance is more significant when it is used in combination with benches. The study also provides comparison of slope profiles based on different criteria’s and recommend the selection profile based on site-specific considerations.

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Development and validation of the Terrain Stability model for assessing landslide risk during heavy rain infiltration

10.5194/nhess-2018-192 ◽

2018 ◽

Author(s):

Alfonso Gutiérrez-Martín ◽

Miguel Ángel Herrada ◽

José Ignacio Yenes Gallego ◽

Ricardo Castedo Ruiz

Keyword(s):

Slope Stability ◽

Limit Equilibrium ◽

Heavy Rain ◽

Economic Losses ◽

Landslide Risk ◽

Stability Of Slopes ◽

Stability Model ◽

Precipitation Type ◽

Development And Validation ◽

State Assumption

Abstract. Slope stability is a key topic, not only for engineers but also for politicians, due to the considerable monetary and human losses that landslides can cause every year. In fact, it is estimated that landslides have caused thousands of deaths and economic losses amounting to tens of billions of euros per year around the world. The geological stability of slopes is affected by several factors, such as climate, earthquakes, lithology and rock structures, among others. Climate is one of the main factors, especially when large amounts of rainwater are absorbed in short periods of time. Taking into account this issue, we developed an innovative analytical model using the limit equilibrium method supported by a geographic information system (GIS). This model is especially useful for predicting the risk of landslides in scenarios of heavy unpredictable rainfall. A hydrological steady-state assumption was incorporated into this approach. The model, called Terrain Stability (TS), was developed and programmed in MATLAB. This model allows a simulation of the slope stability in a 2D spatial distribution. Many variables measured in the field – topography, precipitation, type of soil – can be added, changed or updated using simple input parameters. To validate the model, we applied it to a real example, that of a landslide which resulted in human and material losses (collapse of a building) at Hundidero, La Viñuela (Málaga) in February 2010.

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ANALISIS KONDISI BAWAH PERMUKAAN DAN RISIKO BENCANA TANAH LONGSOR UNTUK ARAHAN PENATAAN KAWASAN DI DESA TENGKLIK KECAMATAN TAWANGMANGU KABUPATEN KARANGANYAR JAWA TENGAH

Jurnal Sains dan Teknologi Indonesia ◽

10.29122/jsti.v13i2.881 ◽

2013 ◽

Vol 13 (2) ◽

Author(s):

Heru Sri Naryanto

Keyword(s):

Information System ◽

Geographic Information System ◽

Regional Planning ◽

Rainy Season ◽

Great Influence ◽

Landslide Risk ◽

Potential Hazard ◽

Volcanic Deposits ◽

Steep Topography ◽

Steep Slopes

Karanganyar District is a hilly area with steep slopes, rock constituent of young volcanic deposits of Lawu Volcano products, thick soil and relatively high rainfall, so it is potential for large landslides in this region. The landuse in the Karanganyar District including the Tengklik Village is generally dominated by rice fields, seasonal gardens and settlements. Plantation made up in areas with steep topography has great influence on erosion and landslides. Similarly, many settlements are built on a slope so that the area is very vulnerable to the threat of landslides. In the rainy season landslides are common. The potential hazard of landslidesoccurred in 14 sub districts in Karanganyar District. Large landslides have occurred in Karanganyar on December 26, 2007 which claimed the lives of 62 people, with the greatest victims were in the Ledoksari Village, Tawangmangu. The Tengklik Village has already experienced creep type landslides, which have destroyed settlements, roads, seasonalgardens and all existing infrastructure in the area. In order to do the proper handling and anticipation of a catastrophic landslide, a variety of technological applications landslides using geographic information system (GIS) was then carried out, to detect the configuration of 2D geoelectrical subsurface prone areas for landslide risk study and regional planning.

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The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽

10.3390/geosciences11020073 ◽

2021 ◽

Vol 11 (2) ◽

pp. 73

Author(s):

Panagiotis Sitarenios ◽

Francesca Casini

Keyword(s):

Analytical Solution ◽

Slope Stability ◽

Slope Failure ◽

Failure Modes ◽

Pore Water Pressure ◽

Limit Equilibrium ◽

Water Pressure ◽

Three Dimensional ◽

Stability Limit ◽

Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

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Characteristics of slope stability and embankment problems in residual soils in Japan

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(90)95267-5 ◽

1990 ◽

Vol 27 (2) ◽

pp. A114

Author(s):

T. Yamanouchi

Keyword(s):

Slope Stability ◽

Residual Soils

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The contribution of chestnut coppice forests on slope stability in abandoned territory: a case study

Journal of Agricultural Engineering ◽

10.4081/jae.2013.254 ◽

2013 ◽

Vol 44 (2s) ◽

Cited By ~ 2

Author(s):

Chiara Bassanelli ◽

Gian Battista Bischetti ◽

Enrico Antonio Chiaradia ◽

Lorenzo Rossi ◽

Chiara Vergani

Keyword(s):

Slope Stability ◽

Root Diameter ◽

Slope Instability ◽

Economic Changes ◽

Sweet Chestnut ◽

Forestry Practices ◽

Short Rotation ◽

Root Cohesion ◽

Chestnut Coppice ◽

High Level

Sweet chestnut has been for many centuries fundamental for the Italian mountainous economies, where this kind of forest was traditionally managed in short rotation to rapidly produce wood biomass. Due to the social and economic changes, which made such management scheme unprofitable especially on the steep and remote slopes, such practice has been mainly abandoned and most of chestnut forests became over-aged and very dense, causing an increase of localized slope instability. In this work the effect of over-aged chestnut coppice forests on shallow landslides was analysed by evaluating and comparing mechanical contribution to soil shear strength provided by root systems in differently managed chestnut stands. The study area is located in Valcuvia (Lombardy Prealps) where three different stands, one managed and the others abandoned (over 40 year aged), established on cohesionless slopes (quaternary moraine deposits) were chosen having care to select homogeneous conditions in terms of substrate, aspect and elevation. As slope steepness strongly affects forestry practices and steeper stands are more frequently abandoned, the considered stands have different terrain inclination, 30-35° in abandoned stands and 13° in the managed one. Slope stability of the three sites was evaluated by applying the infinite slope approach accounting for additional root cohesion and tree surcharge. Additional root cohesion was estimated through the Fiber Boundle Model approach by collecting roots in the field and measuring their resistance in laboratory, and by measuring root diameter and density distribution with depth by the wall technique method. The results, as expected, showed that over-aging does not affect root mechanical properties, whereas it significantly affects root distribution within the soil. In terms of slope stability, when steepness exceeds 35°, instability phenomena can be triggered by high level of soil saturation in the case of over-aged forests, whereas for less extreme cases chestnut forests, although over-aged, are able and fundamental to guarantee safe conditions.

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