Modelling farm vulnerability to flooding: towards the appraisal of vulnerability mitigation policies

In France, two new kinds of flood management policies are promoted: floodplain restoration and vulnerability mitigation. Few experience feedback exist on these policies but they may have strong impacts on farms. Flood management on Rhône River is highly illustrative of these policies and local authorities would like to appraise the efficiency of these policies with an economic tool (Cost-Benefit Analysis) to help decision making. But the current methods of flood damage modelling do not make the appraisal of these policies possible; mainly because they do not take into account the organizational and temporal dimensions of damage formation and propagation at farm scale. After a presentation of the Rhône River context and policies, we review existing methods of flood damage modelling for agriculture and show the interest to focus on the farm scale instead of land plot scale. Based upon the theoretical frameworks for systemic approach, we detail the construction of our conceptual model of farm vulnerability before presenting a case study that shows how the model can be implemented to compute flood damage at farm scale. Finally, the outlooks concerning the use of the model to appraise vulnerability mitigation policies and its application at regional scale are developed.Modélisation;Vulnérabilité;Langage UML;Évaluation des risques;Exploitation agricole;Inondation

Optic disc drusen and scleral canal size – protocol for a systematic review and meta-analysis

BackgroundAround one in forty patients are diagnosed with optic disc drusen (ODD) during their lifetime. Complications of these acellular deposits range from asymptomatic visual field deficits to artery occlusion and subsequent cecity. Still, the pathogenesis of their emergence remains controversial. In particular, it was suggested 50 years ago that a narrow disc and scleral canal is one factor leading to axoplasmic flow disturbance, which induces ODD formation. However, this hypothesis is still debated today. To evaluate the basis of this theory, we will conduct a systematic review and meta-analysis of studies evaluating the scleral canal size in patients with ODD and in healthy subjects.MethodsWe will search MEDLINE via PubMed, Cochrane, and EMBASE electronic databases to identify articles published before November 29, 2022 that measure the scleral canal size in patients with ODD and in healthy subjects. In addition, grey literature will be searched. The meta-analysis will include studies that include patients with a clinical or imaging diagnosis of ODD and healthy subjects. Additionally, we will perform a subgroup analysis to compare patients with buried ODD and patients with visible ODD. Extracted data from included studies will be presented descriptively, and effect sizes will be computed based on the recommendations from the Cochrane Collaboration handbook.DiscussionThe hypothesis that a narrow scleral canal is a risk factor of ODD has long been debated and this systematic review and meta-analysis should disentangle the different views. Understanding the underlying factors driving the development of ODD should help us focus on patients at risk and develop strategies to prevent advanced stages of the disease in these patients. Besides, focusing on patients with small scleral canals should help us derive associated factors and provide a better understanding of the pathology.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022375110

Quasi-static Free-Boundary Equilibrium of Toroidal Plasma with CEDRES++: Computational Methods and Applications

International audienceWe present a comprehensive survey of the various computational methods in CEDRES++ for finding equilibria of toroidal plasma. Our focus is on free-boundary plasma equilib-ria, where either poloidal field coil currents or the temporal evolution of voltages in poloidal field circuit systems are given data. Centered around a piecewise linear finite element representation of the poloidal flux map, our approach allows in large parts the use of established numerical schemes. The coupling of a finite element method and a boundary element method gives consistent numerical solutions for equilibrium problems in unbounded domains. We formulate a new Newton method for the discretized non-linear problem to tackle the various non-linearities, including the free plasma boundary. The Newton method guarantees fast convergence and is the main building block for the inverse equilibrium problems that we can handle in CEDRES++ as well. The inverse problems aim at finding either poloidal field coil currents that ensure a desired shape and position of the plasma or at finding the evolution of the voltages in the poloidal field circuit systems that ensure a prescribed evolution of the plasma shape and position. We provide equilibrium simulations for the tokamaks ITER and WEST to illustrate the performance of CEDRES++ and its application areas

Caractérisation des stratégies de gestion pour la modélisation de la vulnérabilité des exploitations agricoles aux inondations : Lier les dimensions spatiale, organisationnelle et temporelle d'un système complexe

Les politiques publiques de gestion des inondations s'orientent vers la restauration des champs d'expansion de crue et de réduction de la vulnérabilité, qui auront un impact important sur les exploitations agricoles. L'évaluation des effets de ces politiques sur les exploitations agricoles n'est pas envisageable avec les méthodologies actuelles et le retour d'expérience quasiment inexistant. Il était donc nécessaire de développer un modèle de simulation des dommages directs et induits en prenant en compte la dimension systémique de l'exploitation agricole. Pour cela, nous proposons un modèle conceptuel de la vulnérabilité à l'échelle de l'exploitation agricole et montrons comment il nous a permis de mettre en évidence l'importance des stratégies de gestion post-inondation pour la modélisation des dommages. Nous présentons ensuite les résultats des enquêtes réalisées sur les exploitations arboricoles de la zone aval du Rhône pour la caractérisation de ces stratégies. Enfin, nous montrons comment nous avons intégré dans le modèle de simulation des dommages, les données recueillies par enquêtes. Les premiers résultats de simulation des dommages confirment l'importance de prendre en compte les effets induits de l'inondation sur le système " exploitation agricole ". En perspective, l'utilisation du modèle de simulation des dommages dans le cadre d'une évaluation économique des politiques de réduction de la vulnérabilité des exploitations agricoles sur la zone aval du Rhône est discutée.INONDATION;POLITIQUE PUBLIQUE;EXPLOITATION AGRICOLE;VULNERABILITE;SIMULATION;STRATEGIE

Benchmarking Density Functionals on Structural Parameters of Small-/Medium-Sized Organic Molecules

In this Letter we report the error analysis of 59 exchange-correlation functionals in evaluating the structural parameters of small- and medium-sized organic molecules. From this analysis, recently developed double hybrids, such as xDH-PBE0, emerge as the most reliable methods, while global hybrids confirm their robustness in reproducing molecular structures. Notably the M06-L density functional is the only semilocal method reaching an accuracy comparable to hybrids’. A comparison with errors obtained on energetic databases (including thermochemistry, reaction barriers, and interaction energies) indicate that most of the functionals have a coherent behavior, showing low (or high) deviations on both energy and structure data sets. Only a few of them are more prone toward one of these two properties.A.J.P.-J. and J.C.S.-G. thank the “Ministerio de Economía y Competitividad” of Spain and the “European Regional Development Fund” through Project CTQ2014-55073-P for financial and computational support. X.X. thanks the National Natural Science Foundation of China (Grants 91427301 and 21133004) and the Ministry of Science and Technology (Grant 2013CB834606)