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Auteurs :
Tatard, Lucile

Description :

International audience

85% of people exposed to earthquakes, hurricanes, floods and drought live in developing countries (IPU, 2010). This population is also exposed to the landslide risk as this phenomenon is mainly triggered by earthquakes and rainfall. There is an urgent need to propose methods to evaluate and mitigate the landslide risk for developing countries, where few studies were undergone and data, and information on data, are scarce. In this study, we characterize a landslide inventory set up for the megalopolis of Lima, Peru, by the local geological bureau (INGEMMET). This inventory was set up using satellite images and includes landslides of all ages. It is composed of two landslide types: rockfalls and debris flows (huaycos) that we investigate together and separately. First, we describe qualitatively the landslide occurrences in terms of geology, slope steepness, altitude, etc. We notably find that debris flows occur at altitudes larger than the ones of the rockfalls, probably due to the climatic conditions. Then we find that the rockfalls and debris flows area distributions follow a power law when investigated separately whereas it does not follow a power law when investigated together. This highlights a logical difference of mechanics between the two landslide types. Then, using the dimension of correlation D (Grassberger and Procaccia, 1983) we show that the event spatial occurrences are not uniformly distributed but clustered. It supports the existence of controlling parameters on the spatial occurrence of landslides and the research to identify them. Last, we investigate the relationships between different landslide parameters (geology, altitude, slope steepness, ...) using the linear correlation coefficient r, and we find that all these parameters are independent to each other. This allows us to investigate each parameter separately in terms of landslide susceptibility and to define values for which the landslide susceptibility is low, medium or high for each parameter. The characterization of the landslide database is a necessary step to assess the good quality of the data. It then allows us to pursue our investigation and set up a robust landslide susceptibility analysis using our good-quality inventory.



Mots-clés :
risque - chute de pierres - pente - glissement de terrain - Pérou - Callao - Lima - [SDU] Sciences of the Universe [physics] - [SDU.STU] Sciences of the Universe [physics]/Earth Sciences - [SDU.STU.GM] Sciences of the Universe [physics]/Earth Sciences/Geomorphology

Editeur :
HAL CCSD

Langue :
en

Type de document :
info:eu-repo/semantics/conferenceObject, Conference papers

Source :
Geophysical Research Abstracts; EGU General Assembly 2013; https://hal.archives-ouvertes.fr/hal-01266107; EGU General Assembly 2013, Apr 2013, Vienne, Austria. Geophysical Research Abstracts, 15, p. 5732

Date :
2013-04-07

Contributeurs :
Laboratoire de Géophysique Interne et Tectonophysique (LGIT) ; Observatoire des Sciences de l'Univers de Grenoble (OSUG) ; Université Joseph Fourier - Grenoble 1 (UJF) - Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS) - Université Joseph Fourier - Grenoble 1 (UJF) - Institut national des sciences de l'Univers (INSU - CNRS) - Centre National de la Recherche Scientifique (CNRS) - Laboratoire Central des Ponts et Chaussées (LCPC) - Institut des Sciences de la Terre (ISTerre) ; Université Joseph Fourier - Grenoble 1 (UJF) - Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR) - Institut national des sciences de l'Univers (INSU - CNRS) - Institut de recherche pour le développement [IRD] : UR219 - PRES Université de Grenoble - Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) - Centre National de la Recherche Scientifique (CNRS) - Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR) - Institut de recherche pour le développement [IRD] : UR219 - PRES Université de Grenoble - Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) - Centre National de la Recherche Scientifique (CNRS)
IRD Lima
Pôle de recherche pour l'organisation et la diffusion de l'information géographique (PRODIG) ; Université Panthéon-Sorbonne (UP1) - Institut de Recherche pour le Développement (IRD) - École pratique des hautes études (EPHE) - Université Paris-Sorbonne (UP4) - Université Paris Diderot - Paris 7 (UPD7) - Centre National de la Recherche Scientifique (CNRS)

Identifiants :
hal-01266107
https://hal.archives-ouvertes.fr/hal-01266107

Couverture :

Vienne, Austria