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Abstract. A waste management system plays a leading role in the capacity of an area to restart after flooding, as their impact on post-crisis management can be very considerable. Improving resilience, i.e. enabling it to maintain or recover acceptable operating levels after flooding is primordial. To achieve this, we must understand how the system works for bringing any potential dysfunctions to light and taking preventive measures. Functional analysis has been used for understanding the complexity of this type of system. The purpose of this article is to show the interest behind this type of method and the limits in its use for improving resilience of waste management system as well as other urban technical systems1, by means of theoretical modelling and its application on a study site. 1In a systemic vision of the city, urban technical systems combine all the user service systems that are essential for the city to operate (electricity, water supplies, transport, sewerage, etc.). These systems are generally organised in the form of networks (Coutard, 2010; CERTU, 2005).

Abstract. Urbanization has led to a higher concentration of both persons and property, which increases the potential degree of damage liable to occur in crisis situations. Urban areas have become increasingly complex socio-technical systems where the inextricable tangle of activities, networks and regions means disruptions propagate rather than disseminate. In risk anticipation, measures of prevention and anticipation are generally defined by using hazard modelling. The relevance of this approach may be subject to discussion (Zevenbergen et al., 2011) particularly in view of the large number of uncertainties that make hazard evaluation so difficult. For this reason, uncertainty analysis is initially called upon in a theoretical approach before any applied approach. Generally, the uncertainty under study is not assessed in hydrological studies. This uncertainty is related to the choice of evaluation model used for extreme values. This application has been used on the territory of the town of Besançon in eastern France. Strategic orientations for regional resilience are presented taking into account the high levels of uncertainty concerning estimates for possible flow rates.

Abstract. This paper deals with the failure risk of masonry constructions under the effect of floods. It is developed within a probabilistic framework, with loads and resistances considered as random variables. Two complementary approaches have been investigated for this purpose: – a global approach based on combined effects of several governing parameters with individual weighted contribution (material quality and geometry, presence and distance between columns, beams, openings, resistance of the soil and its slope. . .), – and a reliability method using the failure mechanism of masonry walls standing out-plane pressure. The evolution of the probability of failure of masonry constructions according to the flood water level is analysed. The analysis of different failure probability scenarios for masonry walls is conducted to calibrate the influence of each "vulnerability governing parameter" in the global approach that is widely used in risk assessment at the urban or regional scale. The global methodology is implemented in a GIS that provides the spatial distribution of damage risk for different flood scenarios. A real case is considered for the simulations, i.e. Cheffes sur Sarthe (France), for which the observed river discharge, the hydraulic load according to the Digital Terrain Model, and the structural resistance are considered as random variables. The damage probability values provided by both approaches are compared. Discussions are also developed about reduction and mitigation of the flood disaster at various scales (set of structures, city, region) as well as resilience.

In the last 5 years in France, we have observed that each new flood event exposes the weaknesses of the existing prevention system as well as the local weakness. Such events raise questions about the relevance and the effectiveness of the means of prevention. But these events also reveal resistance of the exposed territories, which shows that effective and adequate local strategies exist. There are various methods to evaluate the weakness, or vulnerability of an area, but since the last ten years the qualitative approach of vulnerability in flood risks became more important. Nevertheless, local authorities are often unable to evaluate the vulnerabilities of their territory. Local decision makers request tools for a better assessment of flooding vulnerability. Thus, many approaches of the weakness and the resistance of frequently flooded territories were developed on various scales. These approaches are often partial and contextual. There is a clear need for a support of the evaluation of vulnerability. However, there are obvious synergies between these different approaches, with regard to data retrieval and the establishment of adequate information systems taking into account the vulnerability of a specific territory. The paper develops a methodology aimed to organize into a software tool the choice of vulnerability indicators and the integration of the point of view of various stakeholders (economists, town planners, experts, political leaders, etc). This challenge is based on three simple statements: break down of the problems of vulnerability into homogeneous subsets and manage them; articulation of these subsets in a graphical interface allowing the presentation of interactions between the indicators of vulnerability and compare the opposed visions of vulnerability. The interface of the tool integrates various vulnerability indicators, which are organised in several categories, in order to allow a flexible and efficient vulnerability analysis.

Abstract. In the last 5 years in France, we have observed that each new flood event exposes the weaknesses of the existing prevention system as well as the local weakness. Such events raise questions about the relevance and the effectiveness of the means of prevention. But these events also reveal resistance of the exposed territories, which shows that effective and adequate local strategies exist. There are various methods to evaluate the weakness, or vulnerability of an area, but since the last ten years the qualitative approach of vulnerability in flood risks became more important. Nevertheless, local authorities are often unable to evaluate the vulnerabilities of their territory. Local decision makers request tools for a better assessment of flooding vulnerability. Thus, many approaches of the weakness and the resistance of frequently flooded territories were developed on various scales. These approaches are often partial and contextual. There is a clear need for a support of the evaluation of vulnerability. However, there are obvious synergies between these different approaches, with regard to data retrieval and the establishment of adequate information systems taking into account the vulnerability of a specific territory. The paper develops a methodology aimed to organize into a software tool the choice of vulnerability indicators and the integration of the point of view of various stakeholders (economists, town planners, experts, political leaders, etc). This challenge is based on three simple statements: break down of the problems of vulnerability into homogeneous subsets and manage them; articulation of these subsets in a graphical interface allowing the presentation of interactions between the indicators of vulnerability and compare the opposed visions of vulnerability. The interface of the tool integrates various vulnerability indicators, which are organised in several categories, in order to allow a flexible and efficient vulnerability analysis.

In the last 5 years in France, we have observed that each new flood event exposes the weaknesses of the existing prevention system as well as the local weakness. Such events raise questions about the relevance and the effectiveness of the means of prevention. But these events also reveal resistance of the exposed territories, which shows that effective and adequate local strategies exist. There are various methods to evaluate the weakness, or vulnerability of an area, but since the last ten years the qualitative approach of vulnerability in flood risks became more important. Nevertheless, local authorities are often unable to evaluate the vulnerabilities of their territory. Local decision makers request tools for a better assessment of flooding vulnerability. Thus, many approaches of the weakness and the resistance of frequently flooded territories were developed on various scales. These approaches are often partial and contextual. There is a clear need for a support of the evaluation of vulnerability. However, there are obvious synergies between these different approaches, with regard to data retrieval and the establishment of adequate information systems taking into account the vulnerability of a specific territory. The paper develops a methodology aimed to organize into a software tool the choice of vulnerability indicators and the integration of the point of view of various stakeholders (economists, town planners, experts, political leaders, etc). This challenge is based on three simple statements: break down of the problems of vulnerability into homogeneous subsets and manage them; articulation of these subsets in a graphical interface allowing the presentation of interactions between the indicators of vulnerability and compare the opposed visions of vulnerability. The interface of the tool integrates various vulnerability indicators, which are organised in several categories, in order to allow a flexible and efficient vulnerability analysis.