8 research outputs found
Risk assessment and decision support for improving the resilience of Ăle-de-France's urban technical networks to flooding
Les rĂ©seaux techniques urbains constituent des infrastructures critiques pour le bon fonctionnement et la rĂ©silience des territoires. Toutefois, ces mĂȘmes rĂ©seaux prĂ©sentent diffĂ©rentes formes de vulnĂ©rabilitĂ©s aux alĂ©as naturels et anthropiques, pouvant causer leur endommagement et lâarrĂȘt des services urbains quâils permettent dâassurer. Ces vulnĂ©rabilitĂ©s peuvent conduire Ă des dysfonctionnements parfois imprĂ©visibles et potentiellement mĂȘme plus sĂ©vĂšres que le seul impact causĂ© par lâalĂ©a initiateur (dĂ©faillances en cascade).Dans le cas de lâIle-de-France, la vulnĂ©rabilitĂ© des rĂ©seaux face aux inondations constitue un sujet majeur de risque et de rĂ©silience territoriale. On compte une multitude dâimpacts directs potentiels des crues sur les infrastructures et des liens dâinterdĂ©pendances complexes entres infrastructures, rĂ©seaux et services. Afin de doter les gestionnaires dâoutils appropriĂ©s Ă ces enjeux, cette recherche ambitionne « lâĂ©laboration dâune approche mĂ©thodologique pertinente pour la rĂ©duction des vulnĂ©rabilitĂ©s des rĂ©seaux face aux crues ». Cette approche mĂ©thodologique a pour vocation dâassister les gestionnaires de rĂ©seaux franciliens dans les processus dâidentification, de caractĂ©risation, de quantification et de maitrise les risques induits par les diffĂ©rentes formes de vulnĂ©rabilitĂ©s de leurs rĂ©seaux.Lâapproche mĂ©thodologique proposĂ©e sâarticule autour de deux grands axes: la quantification des risques et lâoptimisation multicritĂšres de lâallocation des mesures de leur maitrise. Elle mobilise diffĂ©rentes mĂ©thodes propres Ă lâanalyse des risques, Ă lâintĂ©gration de lâexpertise et Ă la quantification des incertitudes, Ă lâaide Ă la dĂ©cision multicritĂšre et Ă lâoptimisation mathĂ©matique; afin de planifier efficacement les actions de rĂ©duction de vulnĂ©rabilitĂ©s des rĂ©seaux franciliens. Notre dĂ©marche de recherche comporte trois Ă©tapes principales:âą Le dĂ©veloppement dâune dĂ©marche dĂ©terministe pour lâanalyse des vulnĂ©rabilitĂ©s des rĂ©seaux techniques urbains. Celle-ci permet lâidentification et la formalisation des modes de dĂ©faillance dâun rĂ©seau exposĂ© aux crues. Elle permet Ă©galement la quantification de la criticitĂ© individuelle de chaque composant dans les scĂ©narios possibles de dĂ©faillance.âą LâĂ©laboration dâune dĂ©marche fiabiliste pour lâanalyse des vulnĂ©rabilitĂ©s des rĂ©seaux, complĂ©mentaire Ă lâanalyse dĂ©terministe. Elle permet la prise en compte de la vraisemblance des modes de dĂ©faillances identifiĂ©s et la construction dâindicateurs fiabilistes pour Ă©valuer la criticitĂ© de chaque composant dâun rĂ©seau analysĂ© en situation de crue.âą La construction dâun outil dâaide Ă la dĂ©cision pour la rationalisation et lâoptimisation du processus de rĂ©duction des vulnĂ©rabilitĂ©s des rĂ©seaux face aux crues. Cet outil mobilise les rĂ©sultats des deux dĂ©marches dĂ©terministe et fiabiliste pour la caractĂ©risation de la criticitĂ© globale de chaque composant dâun rĂ©seau exposĂ© aux crues. Il permet aussi dâassister les gestionnaires de rĂ©seaux dans lâĂ©laboration de stratĂ©gies optimales de rĂ©duction des vulnĂ©rabilitĂ©s en fonction des budgets dâinvestissement disponibles.La validitĂ© ainsi que la portĂ©e opĂ©rationnelle de notre dĂ©marche sont Ă©prouvĂ©es tout au long de cette recherche, Ă travers des chapitres dâapplication et de valorisation dĂ©diĂ©s Ă lâanalyse dâun tronçon ferroviaire urbain faisant face au risque inondation. Des exemples dâapplication simples sur dâautres rĂ©seaux sont Ă©galement fournis dans les diffĂ©rentes parties du mĂ©moireUrban technical networks are assets that are critical for the proper functioning and the resilience of territories. However, these networks present different vulnerabilities to natural and man-made hazards, which can cause their damage and the interruption of the urban service they provide. These vulnerabilities can lead to damages or malfunctions that are intuitively unpredictable and more severe than the initial impact of a hazard (cascading failures).In the case of Ile-de-France, the vulnerability of networks to flooding is a major issue of risk and territorial resilience. There are many potential direct impacts of floods on infrastructures and complex interdependencies between infrastructures, networks and services. In order to provide managers with the appropriate tools to address these issues, this research aims to"develop a relevant methodological approach for reducing the vulnerability of these networks to flooding". This methodological approach is intended to assist Ile-de-France' networks operators in the processes of identifying, characterizing, quantifying and controlling the risks induced by the various forms of their networks' vulnerabilities.Our methodological approach is structured mainly according to two axes: risk quantification and multicriteria optimization of the allocation of risk control measures. It mobilizes different methods specific to risk analysis, integration of expertise and quantification of uncertainties, multi-criteria decision support and mathematical optimization, in order to effectively plan measures for reducing networks vulnerabilities. Our work includes three main steps:âą The development of a deterministic approach for analyzing the vulnerabilities of urban technical networks. This approach allows the identification and the formalization of a network's failure modes, when exposed to floods. It also allows the quantification of the individual criticality of each component in the possible failure scenarios". The development of a reliabilistic approach for the analysis of networks vulnerabilities, in complement to the deterministic approach. It allows taking into account the likelihood of the identified failure modes and the construction of reliability indicators to evaluate the criticality of a network's components under flood conditions.âą The construction of a decision support tool for optimizing the process of mitigating networks' vulnerabilities to flooding. This tool mobilizes the results of both the deterministic and the reliabilistic approaches for the assessment of the global criticality of each component of a network. It also allows to assist a networkâs operator in developing optimal strategies for reducing vulnerabilities based on the available budgets.The validity of our approach is demonstrated in this research, through application chapters dedicated to the analysis of an urban railway network facing flood risk. Examples of simple applications on other networks are also provided in the different parts of the thesi
Analyse Des Risques et Aide Ă la DĂ©cision pour lâAmĂ©lioration de la RĂ©silience des RĂ©seaux Techniques Urbains Franciliens Face aux Crues
605 pagesUrban technical networks are assets that are critical for the proper functioning and the resilience of territories. However, these networks present different vulnerabilities to natural and man-made hazards, which can cause their damage and the interruption of the urban service they provide. These vulnerabilities can lead to damages or malfunctions that are intuitively unpredictable and more severe than the initial impact of a hazard (cascading failures).In the case of Ile-de-France, the vulnerability of networks to flooding is a major issue of risk and territorial resilience. There are many potential direct impacts of floods on infrastructures and complex interdependencies between infrastructures, networks and services. In order to provide managers with the appropriate tools to address these issues, this research aims to"develop a relevant methodological approach for reducing the vulnerability of these networks to flooding". This methodological approach is intended to assist Ile-de-France' networks operators in the processes of identifying, characterizing, quantifying and controlling the risks induced by the various forms of their networks' vulnerabilities.Our methodological approach is structured mainly according to two axes: risk quantification and multicriteria optimization of the allocation of risk control measures. It mobilizes different methods specific to risk analysis, integration of expertise and quantification of uncertainties, multi-criteria decision support and mathematical optimization, in order to effectively plan measures for reducing networks vulnerabilities. Our work includes three main steps:âą The development of a deterministic approach for analyzing the vulnerabilities of urban technical networks. This approach allows the identification and the formalization of a network's failure modes, when exposed to floods. It also allows the quantification of the individual criticality of each component in the possible failure scenarios". The development of a reliabilistic approach for the analysis of networks vulnerabilities, in complement to the deterministic approach. It allows taking into account the likelihood of the identified failure modes and the construction of reliability indicators to evaluate the criticality of a network's components under flood conditions.âą The construction of a decision support tool for optimizing the process of mitigating networks' vulnerabilities to flooding. This tool mobilizes the results of both the deterministic and the reliabilistic approaches for the assessment of the global criticality of each component of a network. It also allows to assist a networkâs operator in developing optimal strategies for reducing vulnerabilities based on the available budgets.The validity of our approach is demonstrated in this research, through application chapters dedicated to the analysis of an urban railway network facing flood risk. Examples of simple applications on other networks are also provided in the different parts of the thesis.Les rĂ©seaux techniques urbains constituent des infrastructures critiques pour le bon fonctionnement et la rĂ©silience des territoires. Toutefois, ces mĂȘmes rĂ©seaux prĂ©sentent diffĂ©rentes formes de vulnĂ©rabilitĂ©s aux alĂ©as naturels et anthropiques, pouvant causer leur endommagement et lâarrĂȘt des services urbains quâils permettent dâassurer. Ces vulnĂ©rabilitĂ©s peuvent conduire Ă des dysfonctionnements parfois imprĂ©visibles et potentiellement mĂȘme plus sĂ©vĂšres que le seul impact causĂ© par lâalĂ©a initiateur (dĂ©faillances en cascade).Dans le cas de lâIle-de-France, la vulnĂ©rabilitĂ© des rĂ©seaux face aux inondations constitue un sujet majeur de risque et de rĂ©silience territoriale. On compte une multitude dâimpacts directs potentiels des crues sur les infrastructures et des liens dâinterdĂ©pendances complexes entres infrastructures, rĂ©seaux et services. Afin de doter les gestionnaires dâoutils appropriĂ©s Ă ces enjeux, cette recherche ambitionne « lâĂ©laboration dâune approche mĂ©thodologique pertinente pour la rĂ©duction des vulnĂ©rabilitĂ©s des rĂ©seaux face aux crues ». Cette approche mĂ©thodologique a pour vocation dâassister les gestionnaires de rĂ©seaux franciliens dans les processus dâidentification, de caractĂ©risation, de quantification et de maitrise les risques induits par les diffĂ©rentes formes de vulnĂ©rabilitĂ©s de leurs rĂ©seaux.Lâapproche mĂ©thodologique proposĂ©e sâarticule autour de deux grands axes: la quantification des risques et lâoptimisation multicritĂšres de lâallocation des mesures de leur maitrise. Elle mobilise diffĂ©rentes mĂ©thodes propres Ă lâanalyse des risques, Ă lâintĂ©gration de lâexpertise et Ă la quantification des incertitudes, Ă lâaide Ă la dĂ©cision multicritĂšre et Ă lâoptimisation mathĂ©matique; afin de planifier efficacement les actions de rĂ©duction de vulnĂ©rabilitĂ©s des rĂ©seaux franciliens. Notre dĂ©marche de recherche comporte trois Ă©tapes principales:âą Le dĂ©veloppement dâune dĂ©marche dĂ©terministe pour lâanalyse des vulnĂ©rabilitĂ©s des rĂ©seaux techniques urbains. Celle-ci permet lâidentification et la formalisation des modes de dĂ©faillance dâun rĂ©seau exposĂ© aux crues. Elle permet Ă©galement la quantification de la criticitĂ© individuelle de chaque composant dans les scĂ©narios possibles de dĂ©faillance.âą LâĂ©laboration dâune dĂ©marche fiabiliste pour lâanalyse des vulnĂ©rabilitĂ©s des rĂ©seaux, complĂ©mentaire Ă lâanalyse dĂ©terministe. Elle permet la prise en compte de la vraisemblance des modes de dĂ©faillances identifiĂ©s et la construction dâindicateurs fiabilistes pour Ă©valuer la criticitĂ© de chaque composant dâun rĂ©seau analysĂ© en situation de crue.âą La construction dâun outil dâaide Ă la dĂ©cision pour la rationalisation et lâoptimisation du processus de rĂ©duction des vulnĂ©rabilitĂ©s des rĂ©seaux face aux crues. Cet outil mobilise les rĂ©sultats des deux dĂ©marches dĂ©terministe et fiabiliste pour la caractĂ©risation de la criticitĂ© globale de chaque composant dâun rĂ©seau exposĂ© aux crues. Il permet aussi dâassister les gestionnaires de rĂ©seaux dans lâĂ©laboration de stratĂ©gies optimales de rĂ©duction des vulnĂ©rabilitĂ©s en fonction des budgets dâinvestissement disponibles.La validitĂ© ainsi que la portĂ©e opĂ©rationnelle de notre dĂ©marche sont Ă©prouvĂ©es tout au long de cette recherche, Ă travers des chapitres dâapplication et de valorisation dĂ©diĂ©s Ă lâanalyse dâun tronçon ferroviaire urbain faisant face au risque inondation. Des exemples dâapplication simples sur dâautres rĂ©seaux sont Ă©galement fournis dans les diffĂ©rentes parties du mĂ©moir
Evaluating the Implementation of the âBuild-Back-Betterâ Concept for Critical Infrastructure Systems: Lessons from Saint-Martinâs Island Following Hurricane Irma
International audienceA limited number of studies in the scientific literature discuss the âBuild-Back-Betterâ (BBB) critical infrastructure (CI) concept. Investigations of its operational aspects and its efficient implementation are even rarer. The term âBetterâ in BBB is often confusing to practitioners and leads to unclear and non-uniform objectives for guiding accurate decision-making. In an attempt to fill these gaps, this study offers a conceptual analysis of BBBâs operational aspects by examining the term âBetterâ. In its methodological approach, this study evaluates the state of Saint-Martinâs CI before and after Hurricane Irma and, accordingly, reveals the indicators to assess during reconstruction projects. The proposed methods offer practitioners a guidance tool for planning efficient BBB CI projects or for evaluating ongoing programs through the established BBB evaluation grid. Key findings of the study offer insights and a new conceptual equation of the BBB CI by revealing the holistic and interdisciplinary connotations behind the term âBetterâ CI: âBuild-Back-resilientâ, âBuild-Back-sustainableâ, and âBuild-Back-accessible to all and upgraded CIâ. The proposed explanations can facilitate the efficient application of BBB for CI by operators, stakeholders, and practitioners and can help them to contextualize the term âBetterâ with respect to their area and its CI systems. View Full-Tex
Examining the benefits of the build back better concept for Parisian critical infrastructures vulnerable to flooding: From build back better to build better before
International audienc
Proposition dâune approche opĂ©rationnelle pour la reconstruction post inondation des infrastructures critiques franciliennes
International audienc
Building Back Better Critical Infrastructures in a flooding context: Proposal of an operational approach
International audienc