A simplified early-warning system for imminent landslide prediction based on failure index fragility curves developed through numerical analysis

Early-warning systems (EWSs) are crucial to reduce the risk of landslide, especially where the structural measures are not fully capable of preventing the devastating impact of such an event. Furthermore, designing and successfully implementing a complete landslide EWS is a highly complex task. The main technical challenges are linked to the definition of heterogeneous material properties (geotechnical and geomechanical parameters) as well as a variety of the triggering factors. In addition, real-time data processing creates a significant complexity, since data collection and numerical models for risk assessment are time consuming tasks. Therefore, uncertainties in the physical properties of a landslide together with the data management represent the two crucial deficiencies in an efficient landslide EWS. Within this study the application is explored of the concept of fragility curves to landslides; fragility curves are widely used to simulate systems response to natural hazards, i.e. floods or earthquakes. The application of fragility curves to landslide risk assessment is believed to simplify emergency risk assessment; even though it cannot substitute detailed analysis during peace-time. A simplified risk assessment technique can remove some of the unclear features and decrease data processing time. The method is based on synthetic samples which are used to define the approximate failure thresholds for landslides, taking into account the materials and the piezometric levels. The results are presented in charts. The method presented in this paper, which is called failure index fragility curve (FIFC), allows assessment of the actual real-time risk in a case study that is based on the most appropriate FIFC. The application of an FIFC to a real case is presented as an example. This method to assess the landslide risk is another step towards a more integrated dynamic approach to a potential landslide prevention system. Even if it does not define absolute thresholds, the accuracy is satisfactory for a preliminary risk assessment, and it can provide more lead-time to understand the hazard level in order to make decisions as compared with a more sophisticated numerical approach. Hence, the method is promising to become an effective tool during landslide emergency.

[1]  A. Yakut,et al.  Development of Analytical Seismic Fragility Curves for Ordinary Highway Bridges in Turkey , 2012 .

[2]  Fabio Casciati,et al.  Fragility analysis of complex structural systems , 1991 .

[3]  Thomas Mendlik,et al.  Possible impacts of climate change on debris-flow activity in the Swiss Alps , 2013, Climatic Change.

[4]  Fumihiko Imamura,et al.  Developing tsunami fragility curves based on the satellite remote sensing and the numerical modeling of the 2004 Indian Ocean tsunami in Thailand , 2011 .

[5]  Masanobu Shinozuka,et al.  DEVELOPMENT OF BRIDGE FRAGILITY CURVES , 1998 .

[6]  P. Versace,et al.  Analysis of landslide triggering conditions in the Sarno area using a physically based model , 2014 .

[7]  Evelyne Foerster,et al.  Parametric studies and quantitative assessment of the vulnerability of a RC frame building exposed to differential settlements , 2010 .

[8]  N. Tamrakar,et al.  Rock Mass Rating and Geological Strength Index of rock masses of Thopal-Malekhu River areas, Central Nepal Lesser Himalaya , 2013 .

[9]  M. Ghafoori,et al.  Geotechnical Assessment and Classification of Ultrabasic Rock Masses in the South of Mashhad based on GSI and RMi Classification Systems , 2014 .

[10]  D Muir Wood,et al.  FLAC and Numerical Modeling in Geomechanics , 2020 .

[11]  Davide Brambilla,et al.  Surface and subsurface non-invasive investigations to improve the characterization of a fractured rock mass , 2012 .

[12]  H Y Kim,et al.  STATISTICAL ANALYSIS OF FRAGILITY CURVES , 2000 .

[13]  Map and Monitoring Slow Ground Deformation in NW Italy Using PSI Techniques , 2015 .

[14]  Evert Hoek,et al.  Practical estimates of rock mass strength , 1997 .

[15]  Giovanni B. Crosta,et al.  Regionalization of rainfall thresholds: an aid to landslide hazard evaluation , 1998 .

[16]  Michael Obersteiner,et al.  Implementation and integrated numerical modeling of a landslide early warning system: a pilot study in Colombia , 2010 .

[17]  M. Sorriso-Valvo,et al.  Deep-seated gravitational slope deformations, related landslides and tectonics , 1994 .

[18]  Thomas Glade,et al.  Quantitative risk analysis for landslides ‒ Examples from Bíldudalur, NW-Iceland , 2004 .

[19]  Julie Carte.  Vancouver, Canada , 2003 .

[20]  Fumihiko Imamura,et al.  Developing Tsunami fragility curves using remote sensing and survey data of the 2010 Chilean Tsunami in Dichato , 2012 .

[21]  T. Rossettoa,et al.  Derivation of vulnerability functions for European-type RC structures based on observational data , 2003 .

[22]  David K Keefer,et al.  Geology. Assessing landslide hazards. , 2007, Science.

[23]  Fariborz,et al.  DEVELOPMENT OF FRAGILITY AND RELIABILITY CURVES FOR SEISMIC EVALUATION OF A MAJOR PRESTRESSED CONCRETE , 2002 .

[24]  Reginald DesRoches,et al.  Seismic fragility methodology for highway bridges using a component level approach , 2006 .

[25]  J. Bommer,et al.  Development of an earthquake loss model for Turkish catastrophe insurance , 2002 .

[26]  Jim W. Hall,et al.  Towards risk-based flood hazard management in the UK , 2002 .

[27]  Bruno Merz,et al.  Development of dike fragility curves for piping and micro-instability breach mechanisms , 2009 .

[28]  R. Dawson,et al.  Improved condition characterisation of coastal defences , 2002 .

[29]  John Douglas,et al.  Physical vulnerability modelling in natural hazard risk assessment , 2007 .

[30]  Laura Longoni,et al.  Remote Sensing for Landslide Investigations: An Overview of Recent Achievements and Perspectives , 2014, Remote. Sens..

[31]  D. Brambilla,et al.  A new geological model for Spriana landslide , 2014, Bulletin of Engineering Geology and the Environment.

[32]  D. Turcotte,et al.  Landslide inventories and their statistical properties , 2004 .

[33]  S. Leroueil,et al.  The Varnes classification of landslide types, an update , 2014, Landslides.

[34]  Fausto Guzzetti,et al.  A geomorphological approach to the estimation of landslide hazards and risks in Umbria, Central Italy , 2002 .

[35]  Matthew C. Larsen,et al.  Assessing Landslide Hazards , 2007, Science.

[36]  E. Eberhardt.  The Hoek–Brown Failure Criterion , 2012, Rock Mechanics and Rock Engineering.

[37]  L. Longoni,et al.  Analysis of Microseismic Activity Within Unstable Rock Slopes , 2015 .

[38]  Daniel Billaux.  FLAC and numerical modeling in geomechanics : proceedings of the second International FLAC Symposium, Lyon/France/29-31 October 2001 , 2001 .

[39]  H. Varum,et al.  Experimental characterization of physical and mechanical properties of schist from Portugal , 2014 .

[40]  M. Terlien.  The determination of statistical and deterministic hydrological landslide-triggering thresholds , 1998 .

[41]  Amico,et al.  Engineering Geology for Society and Territory – Volume 5 Urban Geology , Sustainable Planning and Landscape Exploitation , 2014 .

[42]  Brian D. Collins,et al.  Progressive failure of sheeted rock slopes: the 2009–2010 Rhombus Wall rock falls in Yosemite Valley, California, USA , 2012 .

[43]  H. Jomard,et al.  Morphological analysis of deep-seated gravitational slope deformation (DSGSD) in the western part of the Argentera massif. A morpho-tectonic control? , 2014, Landslides.

[44]  Michel Jaboyedoff,et al.  Experiences from site-specific landslide early warning systems , 2013 .

[45]  D. Varnes.  SLOPE MOVEMENT TYPES AND PROCESSES , 1978 .

[46]  M. Cała,et al.  Slope stability analysis with FLAC and limit equilibrium methods , 2020, FLAC and Numerical Modeling in Geomechanics.

[47]  D. Varnes,et al.  Landslide types and processes , 2004 .

[48]  Jim W. Hall,et al.  Towards risk-based flood hazard management in the UK , 2002 .

[49]  A. Radice,et al.  On integrated sediment transport modelling for flash events in mountain environments , 2012, Acta Geophysica.

[50]  Dina D'Ayala,et al.  A new approach to flood vulnerability assessment for historic buildings in England , 2014 .

[51]  R. Dawson,et al.  A methodology for national-scale flood risk assessment , 2003 .

[52]  R. Bell,et al.  Natural Hazards and Earth System Sciences Quantitative risk analysis for landslides – Examples from Bı́ldudalur , NW-Iceland , 2004 .