Suchergebnisse

The failure of structural flood control to mitigate economic losses has lead to a shift towards new policies: floodplain restoration and vulnerability reduction. The economic appraisal of these policies requires an in-depth evaluation of agricultural damage as they are key indicators to determine the efficiency of these policies. However, existing methods only consider harvest loss. We consider that farm vulnerability depends on sensitivity and ability to recover leading respectively to direct damage and induced damage on activity. Based on this, we propose a vulnerability model which allows evaluating the whole of these damages. Three farmer's profiles are defined depending on their ability to access to external resources (workforce and equipment) to recover after flooding. The "Internal" profile has no external resource as opposed to the "Service" and "Solidarity" profiles which can respectively rely on service providing and solidarity. The model is applied to evaluate damages on three farm types of the Rhône River downstream area with a financial and economic valuation. This reveals that damages endured by the profile "Internal" are much higher than those of the two other profiles. Then, avoided damages resulting from the implementation of mitigation measures to reduce vulnerability are evaluated. We prove that these measures are more efficient and can be implemented with Benefit-Cost ratio higher than one, only for the frequently flooded farms. Mitigation measures are also more efficient for the profile "Internal". To organize solidarity between farms emerges as one of the most interesting measure for all farm types. ; L'échec des politiques structurelles de gestion des inondations à réduire les dommages a orienté les décideurs publics vers la restauration de zones de rétention et la réduction de la vulnérabilité. L'évaluation économique de ces politiques requiert une évaluation fine des dommages agricoles car ils contribuent fortement à déterminer leur efficacité. Or, les méthodes existantes n'intègrent que ...

National audience ; Dans le domaine des inondations, il est de plus en plus prôné des politiques affichant de fait une coexistence des enjeux avec le risque. Le pari de ces politiques reposent sur la possibilité d'adapter efficacement les enjeux situés en zone inondable, plutôt que de les soustraire à l'inondation. Dans un contexte où il est demandé aux gestionnaires d'évaluer l'efficience des projets pour lesquels ils demandent des subventions à différents échelons (locaux, nationaux voire européens) par le biais d'analyse de type coût-bénéfice, ces politiques nécessitent un développement méthodologique pour analyser la vulnérabilité des enjeux et quantifier ainsi, en terme de dommages évités, les bienfaits de leur adaptation. Ces politiques, notamment celles de « restauration des zones d'expansion de crues » ou de « réduction de la vulnérabilité » concernent plus particulièrement le secteur agricole. C'est par exemple le cas sur la basse vallée du Rhône. Nous avons développé, en lien avec les gestionnaires du Rhône, le modèle EVA permettant de répondre à ces exigences pour les exploitations agricoles. Nous montrons comment cette modélisation systémique des exploitations agricoles permet d'estimer plusieurs sources de dommages. Premièrement, cette modélisation permet de tenir compte de ce qui est classiquement considéré, c'est-à-dire les dommages directement en lien avec l'endommagement des composantes physiques de l'exploitation (bâtiments, outils, stocks, parcelles etc.). Elle permet également de tenir compte des conséquences induites sur l'activité de l'exploitation du fait de la perturbation de son organisation interne comme de ses liens avec son environnement (filières amont et aval, marché du travail). Cette possibilité ouvre la possibilité de considérer l'évaluation des politiques dites de « réduction de la vulnérabilité » qui visent à modifier l'organisation des exploitations pour les rendre plus adaptées aux inondations.

En France, peu de travaux ont été consacrés à la caractérisation de la vulnérabilité des zones agricoles exposées aux inondations, encore moins à son utilisation dans le cadre d'une évaluation économique de politique de gestion des inondations. Nous proposons dans cet article un modèle conceptuel de la vulnérabilité agricole pouvant servir à une telle évaluation, lorsque les politiques visent à une modification de l'événement physique à l'origine de l'inondation ou à une modification de la vulnérabilité des enjeux exposés à cet événement. / Flood management policies promoted by French government impact agriculture land in two ways. Firstly, they may be designated as potential areas for flood expansion. Secondly, since the 2003 law, local authorities have the right to flood these areas more than those which have been deemed to be more vulnerable (urban areas). Meanwhile, policy-driven appraisals of flood management projects are becoming commonplace in France. This highlights the need to better understand agricultural vulnerability and to develop methods for quantifying it. To introduce our approach, we first present the research conducted by Plan Loire which marks a shift away from existing practices of agriculture vulnerability assessment by considering vulnerability at the farm scale rather than at the plot scale. Based on ex-post flood damage assessment and the results of stakeholders questionnaires in the agricultural sector, forty seven determinants of farm vulnerability to flooding were identified and classified. These determinants were used to draft a guide for farmers. This guide aims to highlight the impacts their farm activities could face in case of flooding and to identify measures to mitigate their vulnerability. At the present, this guide is used along the Rhone River and will be probably used along the Loire River in the future. The current application of these guides to mitigate vulnerability of farms revealed the need for further research which is partly presented here. By focusing on the farming ...

International audience ; Recent catastrophic flood events such as Elbe in 2002 or Rhône in 2003 have shown limits of flood management policies relying on dykes protection: worsening of flood impacts downstream, increased damage by dykes rupture. Those events, among others, contributes to radical changes on the philosophy of flood prevention, with the promotion of new orientations for mitigating flood exposition. Two new trends may have a significant impact on rural areas: floodplain restoration and vulnerability mitigation. The Rhône River program, which is an contract of objectives signed between French Government and local collectivites,is highly illustrative of these new trends and their impact on agricultural sector. In this program, it appears that areas to be concerned by floodplain restoration are agricultural ones, because their supposed vulnerability to flood is expected to be less important to urban areas. As a consequence, agricultural sector is particularly concerned by planned actions on mitigation of assets vulnerability, an important part of the program (financial support of European Union of 7.5 Million euros). Mitigation of agricultural assets vulnerability reveals particularly interesting for two following reasons. Firstly, it is a way to maintain agricultural activities in floodplains yet existing, without promoting flood protection. Secondly, in case of floodplain restoration, vulnerability mitigation is a way for local authorities to compensate over-flooding impacts. In practice, local authorities may financially support farmers for implementing measures to mitigate their farm vulnerability. On the Rhône River, an important work has already been done to identify farm vulnerability to flooding, and propose measures to mitigate it. More than 3 000 farms exposed to flood risk have been identified representing 88 690 ha of agricultural areas which is estimated to generate damage between 400 and 800 Million euros depending on the season of occurrence for a catastrophic flood. In the case of farm ...