A two-step fusion process for multi-criteria decision applied to natural hazards in mountains

Mountain river torrents and snow avalanches generate human and material damages with dramatic consequences. Knowledge about natural phenomenona is often lacking and expertise is required for decision and risk management purposes using multi-disciplinary quantitative or qualitative approaches. Expertise is considered as a decision process based on imperfect information coming from more or less reliable and conflicting sources. A methodology mixing the Analytic Hierarchy Process (AHP), a multi-criteria aid-decision method, and information fusion using Belief Function Theory is described. Fuzzy Sets and Possibilities theories allow to transform quantitative and qualitative criteria into a common frame of discernment for decision in Dempster-Shafer Theory (DST ) and Dezert-Smarandache Theory (DSmT) contexts. Main issues consist in basic belief assignments elicitation, conflict identification and management, fusion rule choices, results validation but also in specific needs to make a difference between importance and reliability and uncertainty in the fusion process

AHP and uncertainty theories for decision making using the ER-MCDA methodology

International audienceIn this paper, we present the ER-MCDA methodology for multi-criteria decision-making based on imperfect information coming from more or less reliable and conflicting sources. The Analytic Hierarchy Process (AHP), Fuzzy Sets, Possibility and Belief Functions theories are combined to take a decision based on imprecise and uncertain evaluations of quantitative, qualitative criteria. Classical aggregation of criteria is replaced by a two-step fusion process using advanced fusion rules based on the Dezert-Smarandache Theory (DSmT) that allows to make a difference between importance, reliability and uncertainty of information sources and contents

Applying new uncertainty related theories and multicriteria decision analysis methods to snow avalanche risk management

International audienceMaking the best decision in the event of a snow avalanche encounters problems in the assessment and management process because of the lack of information and knowledge on natural phenomena and the heterogeneity and reliability of the information sources available (historical data, field measurements, and expert assessments). One major goal today is therefore to aid decision making by improving the quality, quantity, and reliability of the available information. This article presents a new method called evidential reasoning and multicriteria decision analysis (ER-MCDA) to help decision making by considering information imperfections arising from several more or less reliable and possibly conflicting sources of information. First, the principles of the existing methods are reviewed. Classical methods of multicriteria decision making and existing theories attempting to represent and propagate information imperfections are described. In a second point, we describe the principle of the ER-MCDA method combining multicriteria decision analysis (MCDA) to model the decision-making process and fuzzy sets theory, possibility theory, and evidence theory to represent, fuse and propagate information imperfections. Experts, considered more or less reliable, provide imprecise and uncertain evaluations of quantitative and qualitative criteria that are combined through information fusion. The method is applied to a simplified version of an existing system aiming to evaluate the sensitivity of avalanche sites. This new method makes it possible to consider both the importance of the information available and reliability in the decision process. It also contributes to improving traceability. Other developments designed to handle other assessment problems such as avalanche triggering conditions or data quality are in progress

2015 Minnesota Undergraduate Scholars Posters at St. Paul Abstract Booklet

Abstract booklet from the second Minnesota Undergraduate Scholars Posters at St. Paul event. The multi-disciplinary poster presentation was held on February 26, 2015 from 2:00-4:00 PM in the Veterans Service Building. Participating campuses included: Bemidji State University; Inver Hills Community College; Metropolitan State University; Minneapolis Community and Technical College; Minnesota State University, Mankato; Minnesota State University, Moorhead; Rochester Community and Technical College; St. Cloud State University; Southwest Minnesota State University and Winona State University

A Modeling Framework for Efficacy Assessment and Preventive Maintenance of Torrential Protection Works

International audienceNatural phenomena in mountains put people and assets at risk. Risk reduction measures can be either structural (protection works) or non-structural (risk zoning maps). In torrential watersheds of the French mountains, many checkdams have been built since the 19th century. As any civil engineering structure, those dams age and their failures may have severe effects on protected areas. Thus, preserving their level of efficacy is of a high interest. In a context of decreasing public budgets, it is necessary to assess their structural, functional and economic efficacy in order to quantify the residual risk and to choose the best maintenance strategies. Recently, a global approach has been proposed to integrate safety and reliability analysis, multicriteria decision-making methods, and information imperfection processing. However, it does not help in choosing the best strategy to maintain protection devices mainly because it does not cover all aspects related to protection works management making the balance between investment, preventive maintenance costs, and risk evolution. This paper develops a contribution addressing all those issues and proposes a new modeling approach based on Petri nets, whose main steps are: 1) to describe multi-scale protection works systems interaction between both natural and technological systems’ components; 2) to analyze structural and functional failure modes; 3) to develop a Petri net model for deterioration and maintenance modeling; 4) to compare different maintenance strategies under different hypothesis on degradation and damage processes

Focus - Caractérisation des altérations de la géomorphologie naturelle d'un cours d'eau Application du Morphological Quality Index (MQI) aux projets d'aménagement du Grand Buëch à La Faurie

La réalisation d'un projet d'aménagement de cours d'eau nécessite une étude en amont mettant en jeu des connaissances sur l'état géomorphologique initial de la rivière et ses altérations potentielles, éléments qui restent encore difficiles à caractériser pour les gestionnaires. Dans cet article, les auteurs proposent une méthode accessible, simple, standard et fondée sur de solides bases scientifiques pour évaluer de façon concrète et quantifiable l'intérêt d'un projet du point de vue géomorphologique

A Cost-Effectiveness Protocol for Flood-Mitigation Plans Based on Leeds’ Boxing Day 2015 Floods

Inspired by the Boxing Day 2015 flood of the River Aire in Leeds, UK, and subsequent attempts to mitigate adverse consequences of flooding, the goals considered are: (i) to revisit the concept of flood-excess volume (FEV) as a complementary diagnostic for classifying flood events; (ii) to establish a new roadmap/protocol for assessing flood-mitigation schemes using FEV; and, (iii) to provide a clear, graphical cost-effectiveness analysis of flood mitigation, exemplified for a hypothetical scheme partially based on actual plans. We revisit the FEV concept and present it as a three-panel graph using thresholds and errors. By re-expressing FEV as a 2m -deep square lake of equivalent capacity, one can visualise its dimensions in comparison with the river valley considered. Cost-effectiveness of flood-mitigation measures is expressed within the FEV square-lake; different scenarios of our hypothetical flood-mitigation scheme are then presented and assessed graphically, with each scenario involving a combination, near and further upstream of Leeds, of higher (than existing) flood-defence walls, enhanced flood-plain storage sites, giving-room-to-the-river bed-widening and natural flood management. Our cost-effectiveness analysis is intended as a protocol to compare and choose between flood-mitigation scenarios in a quantifiable and visual manner, thereby offering better prospects of being understood by a wide audience, including citizens and city-council planners. Using techniques of data analysis combined with general river hydraulics, common-sense and upper-bound estimation, we offer an accessible check of flood-mitigation plans

Evaluation of Efficiency of Torrential Protective Structures With New BF-TOPSIS Methods

Decision-Aid Methods (DAMs) such as the CostBenefit Analysis (CBA) and the Analytical Hierarchy Process (AHP) help decision-makers to rank alternatives or to choose the best one among several potential ones

Культурные последствия глобализации

Mitigation strategies against natural risks in mountainous areas often include protection works against torrential flooding, avalanches or falling rocks. These structures, which are submitted to specific phenomena as well as they are built in a difficult geotechnical context, must be designed in compliance with specific requirements. Torrent control dams based on an active protection concept are often built to limit the risks of bank slip in the upper part of the catchment area. Usually, design of such structures is based on a two-dimensional approach, allowing force reactions applied by the soil to the foundations of the structure to be assessed. Furthermore, the thrust of the bank is seldom taken into account, even if the loading is likely to be the cause of a lot of observed damages. This paper exposes a methodology whose purpose is to improve the modelling of interaction between soil and structure. After an original analytical approach is presented, the main basis of numerical simulation (Finite Element Code) are defined.Les barrages de consolidation visent à limiter l'érosion du chenal d'écoulement des torrents et sont souvent implantés dans des sites où les berges sont fortement instables. Ces zones constituent en effet d'importantes zones d'alimentation en matériaux solides. Les méthodes actuelles de dimensionnement de ces ouvrages restent basées sur une approche bidimensionnelle d'estimation des actions et des réactions du sol en fondation. De même, les actions dues aux poussées des berges instables, qui entraînent de nombreuses pathologies sur les ouvrages, restent mal connues et ne sont pas prises en compte dans les justifications de la stabilité externe et interne des ouvrages. Cet article présente la problématique et la démarche d'étude en vue d'améliorer la connaissance des interactions entre les barrages et le sol au niveau des fondations et des berges. Dans cette perspective, une approche analytique est proposée, puis les bases d'une simulation numérique introduisant la méthode des Eléments Finis sont définies