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Repenser l'évacuation d'une population littorale en milieu urbain dans un contexte multi-risques : le modèle STEP

Abstract : This thesis explore the issue of a pedestrian evacuation of coastal population in an urban environment in case of tsunami and seism, through the implementation of the model STEP. Studies examine two fields: Saint-Laurent-du-Var (France) and Siracusa (Italy). They provide varied configurations of disaster risk exposure and different evacuation strategies for a coastal urban population. Urban environment is the central point of this thesis. First, visibility in an urban context is evaluated through its effect on pedestrian evacuation. Second, by taking into account multi-hazard context through the impacts on buildings from a precursor earthquake and questioning the walkability of evacuation routes to safe areas. The STEP model is a hybrid modelisation combining agent-based and cellular automatons. It is implemented on Saint-Laurent-du-Var based on geographical data (topography, buildings). The tsunami is based on worst-case simulation data. Visibility in an urban context is determined by the height of safe areas and surrounding buildings; it creates “shadow-zones” where people have no line-of-sight to safe areas around them. Walkability of the urban environment is based on the probability of a building collapse according to seismic intensity. Debris may obstruct streets and force people to seek alternative routes to safe areas. According to the worst-case simulation data, three main evacuation scenarios were implemented and explored through parameters related to agents and safe areas. These three scenarios vary the visibility and walkability independently in order to better evaluate the effects of the results. The greatest impact seen within STEP simulations is determined by the location of safe areas and paying attention to seismic activity in an urban environment. This thesis shows the importance of considering specific evacuation requirements for coastal urban environments. It also demonstrates that multi-hazards should be a central concern when defining evacuation strategies for populations.
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Submitted on : Wednesday, May 20, 2020 - 10:21:11 PM
Last modification on : Friday, August 5, 2022 - 12:01:44 PM


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Odile Plattard. Repenser l'évacuation d'une population littorale en milieu urbain dans un contexte multi-risques : le modèle STEP. Géographie. Université Panthéon-Sorbonne - Paris I, 2019. Français. ⟨NNT : 2019PA01H087⟩. ⟨tel-02614430⟩



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