L’industrie minière joue un rôle important dans le développement économique de nos pays. Cependant, les projets miniers font de nos jours face à de sérieuses oppositions tant des communautés locales que des organismes de protection de l'environnement, en raison des impacts potentiels associés à l'extraction minière. Pour concilier les besoins de production de matières premières (assurer le développement économique) et la prise en compte de la préservation de la qualité de l'environnement, il est nécessaire d'évaluer les impacts environnementaux potentiels, conséquences des activités minières avant leur début et choisir les meilleures options d’un point de vue environnemental. L’Étude d’Impact Environnemental (EIE) est une procédure qui permet d’identifier et d’évaluer les impacts d’un projet. Les projets miniers sont assujettis à une telle étude. Or bien que la procédure d’EIE soit obligatoire, la réglementation ne prescrit aucune méthode d’évaluation des impacts ; qui est laissée au choix du praticien. L’objectif général de cette thèse est de proposer une méthode permettant d’évaluer plus efficacement les impacts environnementaux de l’industrie minière. Pour y parvenir deux approches ont été explorées : la méthodologie d’Analyse et d’Évaluation des Impacts environnementaux Miniers (MAEIMIN) développée dans cette thèse et la méthodologie d’Analyse de Cycle Vie (ACV) qui est une technique standardisée ISO. MAEIMIN est une technique basée sur la démarche d’analyse de risque et permet d’évaluer les impacts en prenant en comptes les conditions climatiques, géologiques et de l’état initial de la zone. L’ACV est quant à elle une technique standardisée qui permet d’évaluer les impacts produits sur le site et ceux générés hors du site mais dont les activités génératrices sont liées au système étudié. Ces méthodes ont été mises en œuvre sur une mine d’or en Côte d’Ivoire. MAEIMIN, en prenant en compte les caractéristiques particulières de la zone d’étude, a montré des résultats d’impacts élevés aussi bien pour la pollution des eaux de surface que pour les eaux souterraines, principalement aux étapes d’exploitation et d’après-mine. Cette étude a également montré que les sources de pollution entraînant des impacts de niveau élevé comprennent les dépôts de résidus (terrils et effluents), les sols préalablement contaminées par des retombées de poussière et les travaux miniers. S’agissant de l’ACV, qui est par essence une méthode généraliste, elle a permis plus particulièrement de mettre en évidence des impacts off-site assez significatifs. Pour les effets on-site, l’étude a montré que les impacts sur la santé humaine sont essentiellement dus aux émissions de métaux par les activités d’exploitation (traitement du minerai et gestion des résidus miniers ainsi que les émissions de l’abattage). Enfin, notre travail a permis de montrer une meilleure prise en compte de l’ensemble des impacts par une combinaison de MAEIMIN et de l’ACV dans les procédures d’EIE. / An increasing demand of mineral resources is associated with modern society development. In parallel, mining projects face strong oppositions both from public and from environment protection agencies, due to the potential impacts associated with ore extraction. In order to conciliate the needs of producing raw materials and of taking into account the preservation of the quality of the environment, it is necessary to assess the environmental impact previous to the start of the mining activities. The Environmental Impact Assessment procedure helps to identify and evaluate the environmental impacts of a project. Although Environmental Impact Assessment (EIA) procedure is mandatory, the regulations do not impose any impact assessment method. Thus, EIA practitioners are free to use the method that suits them and their own expertise to estimate the environmental impacts of a project. The main purpose of this work is to propose a method to more effectively evaluate the environmental impacts of the mining industry. To achieve this, two approaches have been explored: the Mining Environmental Impact Assessment Methodology (MEIAM) developed in this thesis and the Life Cycle Assessment (LCA), which is a standardized methodology. MEIAM is based on the risk analysis approach and makes it possible to evaluate the impacts taking into account the climatic and geological conditions and the initial state of the zone. LCA is a standardized technique that assesses the impacts produced on the site and those generated off-site but whose generating activities are related to the system studied. These methods were implemented on a gold mine in Côte d’Ivoire.MEIAM, taking into account the particular characteristics of the study area, showed high impact results for both surface water and groundwater pollution, mainly at the operation and post-closure stages. This study has also shown that pollution sources with high level impacts include tailings, soils previously contaminated by dust fallout and mining works. Regarding the LCA, which is in essence an overall method, it has made it possible to highlight quite significant off-site impacts. For on-site effects, the study showed that the impacts on human health are mainly due to metal emissions from operation activities (ore processing and tailings management as well as blasting). Finally, our work showed that all the impacts were better taken into account by a combination of MEIAM and LCA in the EIA procedures.

Made available in DSpace on 2014-10-09T12:42:14Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:00Z (GMT). No. of bitstreams: 0 / Este trabalho discute os aspectos socioambientais da escolha de um local para instalação de um parque industrial em uma zona rural, e apresenta uma metodologia que identifica e faz uma avaliação prévia dos impactos positivos e negativos para a comunidade e meio-ambiente da região. O texto analisa os aspectos socioambientais encontrados a partir da aplicação da metodologia proposta, e identifica os problemas que precisam ser resolvidos em um pequeno município agrícola que busca crescimento atraindo a implantação de um parque industrial para sua região. Os resultados encontrados fornecem para a indústria, governo e comunidade um entendimento antecipado dos impactos utilizando dados oficiais para identificar e avaliar o que precisa ser feito prioritariamente antes que a localidade seja escolhida e anunciada. São discutidos os critérios de seleção dos indicadores, como recomendado pela Organização das Nações Unidas, e o método de comparação para identificar e priorizar os problemas socioambientais de alta significância que precisam de atenção. A análise dos resultados dos indicadores é feita para gerar recomendações à indústria e ao poder público, com planos de ação que auxiliem na preparação de uma estimativa preliminar dos recursos que serão necessários para melhorar as condições socioambientais da comunidade e possibilitar o desenvolvimento sustentável no longo prazo. Esta informação pode passar a ter um papel importante na avaliação da viabilidade do parque industrial no local estudado. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-26T15:06:02Z No. of bitstreams: 1 Tese- Renan Albuquerque Rodrigues.pdf: 17846569 bytes, checksum: f0ee1270ae29383f2371d60c5710a3f3 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-30T14:46:54Z (GMT) No. of bitstreams: 1 Tese- Renan Albuquerque Rodrigues.pdf: 17846569 bytes, checksum: f0ee1270ae29383f2371d60c5710a3f3 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-30T14:58:17Z (GMT) No. of bitstreams: 1 Tese- Renan Albuquerque Rodrigues.pdf: 17846569 bytes, checksum: f0ee1270ae29383f2371d60c5710a3f3 (MD5) / Made available in DSpace on 2015-06-30T14:58:17Z (GMT). No. of bitstreams: 1 Tese- Renan Albuquerque Rodrigues.pdf: 17846569 bytes, checksum: f0ee1270ae29383f2371d60c5710a3f3 (MD5) Previous issue date: 2013-03-25 / Não Informada / Sustainable development is a global necessity. Regarding the Amazon, there is much to discuss and improve the scope of projects for large hydroelectric plants, built for a generating energy, but because involve forced displacement of populations due to the dams of the rivers, often have large social conflicts created as occurred historically, from projects and military government agencies, in the 1960, 1970 and 1980 in Brazil. One of Amazonian dams that showed great potential for the generation of these conflicts was Balbina. Located in Presidente Figueiredo, in the Central Amazon, the Balbina dam had completed its construction in 1987, flooding an area of 2.400 km2 of forest, reaching about 3.000 families living downstream of the dam. The objective of this study is to analyze social impacts after nearly 25 years of operation of the dam began in 1989. The impacts were analyzed based on: i) participant observation, in which the social context is described, and ii) study and inferential analysis of lifestyles, through analytic ethnography. At around Balbina were interpreted results indicating disaffiliation territorial biases and emotional, fragmentation of belonging, weakening of social relations and demotion of practical actions for the formation of organized groups in the region. How coping and mitigating actions, we chose to highlight: i) suspension and cancellation, immediately, via action by Public Ministry and Procon, of all debts pertaining to electricity bills that have been imputed to those affected by dams, ii ) reorganization of the economy within the living environments to address food insecurity and lack of income, iii) implementation of a model of trade with use aggregate of social currency to those affected by the dam and iv) the orientation of production according to the population diversity upstream and downstream of the dam. / O desenvolvimento sustentável é uma necessidade global. No que tange à Amazônia, há muito o que se debater e melhorar no âmbito dos projetos para grandes centrais hidrelétricas, construídas para a geração energética, mas que, dado implicarem deslocamentos forçados de populações por causa das barragens dos rios, amiúde tem criado amplos conflitos sociais em épocas atuais, tal como ocorreu historicamente, a partir de projetos de organismos e governos militares, nas décadas de 1960, 1970 e 1980 no Brasil. Uma das represas amazônicas que apresentou grande potencial para a geração desses conflitos foi Balbina. Localizada em Presidente Figueiredo, na Amazônia Central, a represa de Balbina teve finalizada sua construção em 1987, alagando uma área de 2.400 km2 de floresta, atingindo cerca de 3 mil famílias que viviam a jusante e montante da usina. O objetivo do presente trabalho foi analisar impactos sociais após duas décadas e meia de operação da hidrelétrica, iniciada em 1989. Os impactos foram analisados a partir de: i) observação participante, em que o contexto social é descrito; e ii) estudo e análise inferencial dos modos de vida, por meio da etnografia analítica. No entorno de Balbina, foram interpretados resultados de vieses de desfiliação territorial e afetiva, fragmentação de pertencimento, enfraquecimento de relações sociais e rebaixamento de ações práticas para a formação de grupos organizados na região. Como ações de enfrentamento e mitigadoras, optou-se por destacar: i) suspensão e cancelamento imediado, via ação judicial, dos passivos financeiros que tenham sido imputadas aos atingidos pela UHE Balbina, ii) reorganização da economia dentro dos ambientes de vivência para enfrentar a insegurança alimentar e a falta de renda, iii) implantação de um modelo de comércio agregador com uso de moeda social para os atingidos pela barragem e iv) a orientação da produção segundo a diversidade populacional a montante e jusante da represa.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / The riverside and marine plains of Cearà state have been occupied in the last 10 years by the marine shrimp culture that has generated social and environmental impacts over these areas. Recently, new areas of these plains in Cearà have been target of the expansion of shrimp farms, especially in Aracati municipality. It is seen that marine shrimp culture is an activity surrounded by matters that sometimes justify the activity moratorium defended by ambientalists, sometimes justify its implementation by the producers, as marine shrimp culture, as other economical activities, generates both negative and positive impacts over the places where it is inserted. By this meaning it becomes necessary to identify the social impacts, as the environmental impacts promoted over the areas of influence of the agro business of marine shrimp culture, from the studied areas, on Aracati municipality on Cearà state, proposing actions that can minimize the negative impacts and reinforce the positive impacts. To do so, researches were realized on the bibliographical sources of the public organs libraries in Fortaleza; visits to various organs that maintain direct relationships with the activity in Aracati municipality, as works on the study field. The marine shrimp culture is an activity of great importance to Aracati municipality because of its direct and indirect generation of work positions. Although, it can be seen that the activity in Aracati is spacely unorganized, generating conflicts against the estuarial environment and other economical activities, as carnauba straw handcraft and fishing on the marsh. The economic-ecological zoning for the activity in matter in Aracati municipality is the correct direction to minimize the negative environmental and social impacts and reinforce the positive impacts promoted by the implementation of marine shrimp culture. / As planÃcies flÃvio-marinhas do Estado do Cearà vÃm sendo ocupadas nos Ãltimos 10 anos pela carcinicultura marinha que tÃm gerado impactos sociais e ambientais. Recentemente novos espaÃos dessas planÃcies no Cearà foram alvo da expansÃo das fazendas de camarÃo, principalmente no MunicÃpio de Aracati. Observa-se que a carcinicultura marinha à uma atividade cercada por questÃes que ora justificam a moratÃria da atividade defendida por ambientalistas, ora justificam a implementaÃÃo da mesma pelos produtores, pois a carcinicultura, assim como outras atividades econÃmicas, gera impactos negativos e positivos nos locais em que se insere. Neste sentido faz-se necessÃrio identificar os impactos sociais assim como os impactos ambientais promovidos nos espaÃos de influÃncia do agronegÃcio da carcinicultura marinha, a partir das Ãreas estudadas, no MunicÃpio de Aracati no Estado do CearÃ, propondo aÃÃes que possam minimizar os impactos negativos e reforÃar os impactos positivos. Para tanto foram realizadas pesquisas nos acervos bibliogrÃficos das bibliotecas de ÃrgÃos pÃblicos em Fortaleza; visitas a vÃrios ÃrgÃos que mantÃm relaÃÃes diretas com a atividade no MunicÃpio de Aracati, assim como trabalhos de campo na Ãrea de estudo. A carcinicultura à uma atividade de suma importÃncia para a economia do MunicÃpio de Aracati em funÃÃo da geraÃÃo direta e indireta de postos de trabalho. Observa-se, porÃm que a atividade em Aracati à desorganizada espacialmente, gerando conflitos com o ambiente estuarino e com outras atividades econÃmicas como o artesanato da palha de carnaÃba e a pesca no manguezal. O Zoneamento EconÃmico-ecolÃgico para a atividade em questÃo no MunicÃpio de Aracati à a direÃÃo correta para que sejam minimizados os impactos ambientais e sociais negativos e reforÃados os impactos positivos promovidos com a implementaÃÃo da carcinicultura.

Esta pesquisa objetiva entender como as práticas de governança corporativa (GC) adotadas por empresas industriais brasileiras relacionam-se com os impactos socioambientais de suas operações. Para atingir o objetivo principal foram formulados os seguintes objetivos específicos: 1) apresentar as características da amostra em termos de setor de atuação, adoção de práticas de GC e níveis de impactos ambientais e sociais; 2) conhecer as associações existentes entre os impactos ambientais, sociais e práticas de GC adotadas pelas empresas brasileiras; 3) verificar se tais associações são influenciadas pelo setor de atuação. A fundamentação teórica aborda as perspectivas teóricas que embasam a relação entre GC e sustentabilidade, os aspectos gerais envolvendo a sustentabilidade e específicos sobre gestão socioambiental, os aspectos gerais sobre o sistema de governança corporativa e aspectos específicos sobre as boas práticas de GC no Brasil, finalizando com as pesquisas nacionais e internacionais que investigaram esse relacionamento. A amostra pesquisada é composta por 46 empresas brasileiras listadas na BM&FBovespa e com dados disponíveis na base de dados ®ASSET4, da Thompson Reuters(TM), de 2010 a 2014. Os níveis de impacto tanto ambiental como social foram determinados em função da posição da empresa em relação às demais componentes da amostra em termos dos seus resultados nas oito variáveis selecionadas, resultando em três categorias: Alto, Médio e Baixo Impacto Social e Ambiental. Analogamente, o nível de adoção às práticas de GC foi determinado em função da posição da empresa em relação às demais em termos de seus resultados em sete variáveis selecionadas. As técnicas empregadas nesta pesquisa, de natureza quantitativa, compreenderam análises descritivas para a apresentação das características da amostra, Teste Qui-quadrado para a identificação das associações existentes entre as práticas de GC e os impactos socioambientais e Análises de Correspondência Múltipla para identificar a influência do setor de atuação sobre tais associações. Os resultados indicam maiores níveis de associação entre a dimensão social e as práticas de GC, comparativamente à dimensão ambiental, embora em ambos os casos tenham sido verificadas associações tanto positivas como negativas. Ademais, a hipótese de que tais associações são influenciadas pelo setor de atuação foi confirmada em ambas as dimensões, indicando, inclusive, que o baixo nível de adoção às práticas de GC ocorre entre em setores de alto impacto tanto ambiental como social. Desta forma, este estudo busca contribuir apresentando evidências de associação entre práticas de GC e impactos socioambientais no contexto brasileiro, possibilitando avançar na busca por conhecimento sobre como o sistema de GC pode contribuir para o alcance de negócios mais sustentáveis e alinhados aos objetivos da sustentabilidade. / This research aims to understand how the corporate governance (CG) practices adopted by Brazilian industrial companies are related to the socio-environmental impacts of their operations. In order to achieve the main objective, the following specific objectives were formulated: 1) to present the characteristics of the sample in terms of activity sector, adoption of CG practices and levels of environmental and social impacts; 2) to know the existing relationships among the environmental, social and CG practices adopted by Brazilian companies; 3) to verify if such combinations are influenced by the sector of performance. Theoretical fundamentals address the theoretical perspectives that support the relationship between CG and sustainability, the general aspects of sustainability and specific aspects of social and environmental management, the general aspects of the corporate governance system and specific aspects of CG practices in Brazil, ending up with national and international surveys that investigated this relationship. The sample surveyed is composed by 46 Brazilian companies listed on the BM&FBovespa, as well as with data available in Thompson Reuters(TM) database ®ASSET4 between 2010 and 2014. The levels of environmental and social impact were determined based on the company\'s position in relation to the other components of the sample in terms of their results within the eight selected variables, resulting in three categories: High, Medium and Low Social and Environmental Impact. Similarly, the level of adoption of CG practices was determined according to the company\'s position in relation to the others in terms of results in seven selected variables. The techniques used at this quantitative nature research have included descriptive analyzes for the presentation of the characteristics of the sample, Qui-square Test for the identification of the relationships among CG practices, social and environmental impacts and Multiple Correspondence Analysis to identify the influence of the activity sector on such associations. The results indicate higher levels of association between the social dimension and CG practices, compared to the environmental dimension, althought in both the cases positives and negatives associations were identified. In addition, the hypothesis that the associations are influenced by the sector of activity was confirmed in both dimensions, indicating that low levels of adoption of CG occurs between sectors with high environmental and social impact. Thus, this study seeks to contribute by presenting evidence of association between practices and socio-environmental impacts at the Brazilian context, allowing to advance in the search of knowledge on how the CG system can contributed to the achievement of a more sustainable development business and aligned with the objectives of sustainability.

Les émissions élevées de CO2 de la filière industrielle de fabrication des tuyaux en fonte résultent pour l'essentiel de l'emploi massif de carbone fossile, charbon et coke, comme combustible et agent réducteur dans les procédés. Substituer du carbone issu de biomasse au carbone fossile en vue de réduire ces émissions de CO2, avec application au cas d'une usine lorraine, a été l'idée de départ de ce travail. Différents types de biomasse ont été envisagés. Le bois et la paille seraient localement disponibles en quantité suffisante pour autoriser une substitution partielle de 20 % du coke. Cette biomasse doit cependant être traitée thermiquement (séchage et pyrolyse) avant de satisfaire les spécifications techniques imposées par les procédés métallurgiques (agglomération, cokerie, haut fourneau). Six scénarios d'usage de la biomasse au haut fourneau ou à l'agglomération ont été sélectionnés. Pour les évaluer sur la base de leur mérite environnemental, nous avons réalisé une analyse de cycle de vie comparative en suivant une approche du type berceau à la porte. Point original de notre étude, l'inventaire de cycle de vie est issu de modèles systémiques des principaux procédés, spécifiquement développés et intégrés à un logiciel de diagrammes de flux. Grâce à ces modèles et notamment celui du haut fourneau, on a pu déterminer les taux de remplacement du coke par trois types de biomasse (charbon de bois en blocs, charbon de bois pulvérisé, bois torréfié pulvérisé) et prédire les modifications de fonctionnement qu'entrainerait l'injection de biomasse. Les résultats de l'analyse de cycle de vie montrent que l'injection de bois, carbonisé ou torréfié, sous forme pulvérisée aux tuyères du haut fourneau serait une solution intéressante d'un point de vue environnemental : baisse des émissions de gaz à effet de serre (-15 %) et des impacts sur la santé humaine et sur les écosystèmes. A l'heure actuelle cependant, le coût économique d'une telle solution demeure excessif / High CO2 emissions from the industrial production of pig iron pipes are mainly due to the massive use of fossil carbon, coal and coke, as a fuel and/or a reducing agent in the processes. The use of biogenic carbon as a substitute for fossil carbon in order to reduce the CO2 emissions, in the case of an existing plant in Lorraine, was the starting point of our work. Different types of biomass were investigated. Local resources for wood and straw would be sufficient for a partial substitution for 20% of the coke. However, this kind of biomass should first undergo a thermal pretreatment step (drying and pyrolysis) to fit the technical requirements for the metallurgical processes (sinter plant, coke oven and blast furnace). Four scenarios of using biomass in the blast furnace or at the sinter plant were selected. To evaluate their environmental performances, we produced a comparative life cycle assessment, using a cradle-to-gate approach. An original feature of our study lies in the use of systems modeling for the determination of the life cycle inventories of the main processes, which were modeled using a flowsheeting software. From these models, particularly the model of the blast furnace, we could evaluate the replacement ratio of three biomass types (charcoal lumps, charcoal fines and torrefied wood fines) for the coke and predict the influence of biomass injection in the blast furnace on its operation. The results of the life cycle assessment show that the injection of pulverized, torrefied or carbonized, wood through the tuyeres of the blast furnace would be an attracting solution from an environmental point of view. It would reduce greenhouse gas emissions by 15%, as well as mitigate the impacts on human health and ecosystems. Yet, the costs associated to such a solution are currently too high

Les traumatismes crâniens demeurent une cause de mortalité importante et entraînent des incapacités graves. La modélisation numérique est un outil moderne pour étudier la biomécanique des chocs crâniens. L’objectif principal de cette thèse a été l’évaluation biomécanique d’un casque de cycliste issu du commerce. Des tests de caractérisation ainsi que des campagnes de chocs normatifs et tangentiels ont permis le développement d’un modèle éléments-finis du casque et sa validation. Afin d’estimer le risque lésionnel encouru lors de chocs réalistes, le modèle de casque a été couplé à un modèle de tête anatomique et différents paramètres intracrâniens ont été calculés. Les valeurs obtenues pour ces paramètres se sont révélées supérieures aux limites de tolérance. Fort de ces constats, une réflexion en profondeur sur la norme EN1078 actuelle a été menée et pour laquelle des modifications ont été proposées afin que le casque protège la tête de façon optimale vis-à-vis de critères biomécaniques. / Traumatic head injuries remain a common cause of death and severe disabilities worldwide. FE modeling of the head is a well accepted tool to study head impact biomechanics. The objective of this PhD thesis was to evaluate the head protection capability offered by a commercial bicycle helmet. Experimental characterization tests, standard and tangential impacts were performed to develop and validate the finite element helmet model. In order to estimate the injury risk sustained in case of realistic head impacts, the helmet model has been coupled to an anatomical head and intracranial parameters were computed. Calculated values were higher than published tolerance limits. An in-deep investigation of the current EN1078 European standard was then carried out and relevant modifications were proposed to assess and optimize bicycle helmets against biomechanical criteria.

La diversité biologique constitue l’un des piliers du fonctionnement des écosystèmes, etun potentiel pour l’adaptation et l’évolution de la vie dans le contexte du changement climatique. Les espèces constituant cette biodiversité sont étroitement connectées de différentes façons. Une diminution de cette biodiversité peut déclencher des effets de cascade et des conséquences largement imprévisibles, bien au delà de la seule réduction apparente du nombre ou de la distribution des espèces. La grande complexité de l’organisation écologique est très souvent un cauchemar pour la prise de décision. Les difficultés commencent avec le choix d’une mesure adéquate de la biodiversité. Une telle mesure est cependant une étape nécessaire si nous voulons prioriser nos actions de gestion de la biodiversité, afin de préserver le plus de diversité possible avec des ressources limitées. Bien que cette thèse ne prétende pas produire des réponses complètes à ces problèmes complexes, elle offre quelques points de réflexion pour la gestion de la biodiversité.Elle se compose de quatre chapitres. Le premier chapitre soulève la question de la gestion d’une biodiversité mélangée, au sein de laquelle des espèces invasives peuvent également s’inviter. Ce chapitre souligne les interconnections entre la sévérité des impacts des invasions biologiques et le contexte dans lequel cette invasion intervient. Considérant les impacts des invasions comme “ambivalents” — i.e. pouvant être positifs, négatifs, ou neutres pour le système dans lequel l’invasion s’installe — nous proposons une typologie afin d’évaluer l’ambivalence des impacts, sur la base de l’identification des sources potentielles de variabilité des impacts. Pour le second chapitre, nous nous concentrons sur la mesure de la biodiversité lorsque l’on tient compte des interactions entre espèces, de façon à produire une version de la métaphore de l’Arche de Noé (Weitzman, 1998) mieux adaptée aux problèmes de conservation in situ. Nous montrons tout d’abord que, lorsque l’on tient compte d’interactions écologiques, le problème défini par Weitzman demeure une solution extrême ; et deuxièmement, qu’un renversement de la hiérarchie des espèces préservées est possible et entièrement déterminée par la catégorie des interactions. Dans le troisième chapitre, nous utilisons le cadre de coût-bénéfice in-situ développé dans le chapitre 2 afin de comparer les résultats de priorisation de deux indices de biodiversité, Weitzman et Rao. Ces deux indices combinent différemment l’information sur les probabilités autonomes de survie des espèces, les interactions écologiques et la dissimilitude entre espèces afin de mesurer la biodiversité. Nous analysons des plans simples de protection de la biodiversité pour chaque indice, et démêlons le rôle joué par les différents éléments d’information nécessaires au calcul du ranking par l’indicateur,dans un écosystème à trois espèces. Nous montrons que chaque indice réalise un compromis qui lui est propre entre ces éléments d’information, et que l’introduction d’interactions écologiques entre plus de deux espèces mène à des conclusions plus complexes. Les interactions écologiques donnent ainsi une information additionnelle importante afin de déterminer les objectifs de conservation. Notre dernier chapitre est une adaptation du cadre d’optimisation défini précédemment. Il élabore une règle de décision myope afin de déterminer quelles invasions doivent être contrôlées en priorité, en tenant compte des coûts de gestion relatifs et les impacts trophiques en cascade. Nous discutons le gradient de la fonction d’objectif composé d’une fonction de diversité W et d’une fonction d’utilité U, afin de déterminer si nous devrions conserver plusieurs ou seulement quelques espèces sous une contrainte de budget. / Biological diversity constitutes one of the major pattern of ecosystem functioning, and a potential for adaptation and evolution of life in the context of climate change. As species are in many ways tightly interconnected, biodiversity loss can trigger large cascade effects and might lead to largely unpredictable consequences, reaching far beyond the visible reduction in the number or distribution of species. The high complexity of ecological organization is often a nightmare for decision-making, starting from accurately measuring biodiversity. This is however a necessary step to take if we want to prioritize action in biodiversity management, in order to preserve as much diversity as possible under limited resources. Though this thesis does not pretend to provide complete answers to those quite complex issues, it provides some reflection points for biodiversity management. It is composed of four chapters. The first chapter raises the issue of dealing with a mixed biodiversity, in which invasive species can be guests. It highlights the interconnections between the severity of the impacts of biological invasions and the contexts in which this invasion occurs. Considering invasion impacts as inherently ''ambivalent'' - i.e. good, bad or neutral for the system in which it arrives - we propose a typology to assess ambivalence in impact, based on the identification of potential sources of impact variability. For the second chapter, we focus on the measurement of biodiversity when accounting for species interactions, which we incorporates into the Noah's Arch problem developed by Weitzman (1998). We then derive a general model for ranking in situ conservation projects. We show firstly that, when accounting for ecological interactions, the problem defined by Weitzman is still an extreme solution, and secondly, that a ranking reversal is possible and completely defined by the interaction categories. In the third chapter, we use the in situ cost-benefit framework developed in Chapter 2 to compare the outcomes of two biodiversity indices, Weitzman's and Rao's. Those two indexes combine information about species survival probability, ecological interaction and distinctiveness in a different way to measure biodiversity; We analyze simple biodiversity protection plans for each index, and disentangle the role played by the different data requirement in the rankings, in a three species ecosystem. We show that such pieces of information will come as a trade-off when considered simultaneously in the measure, and that the introduction of ecological interactions among more than two species lead to more complex conclusions. Ecological interactions thus give important additional information to determine conservation objectives. Our last chapter is an adaptation of the previously defined optimization framework for the prioritization of invasive species management. It elaborates a myopic rule to determine which invasions must be controlled in priority, taking into account relative management costs and trophic cascades impacts. We discuss the gradient of the objective function composed of a diversity function W and a utility function U, to see whether we should retain several or only a few species for management under a budget constraint.

La recherche a porté sur l'évaluation de la durabilité des filières d'anchois (Engraulis ringens) au Pérou. Les pêcheries locales débarquent 6,5 millions de t par an, dont <2% est transformé en produits destinés à la consommation humaine directe (CHD) et 98% farine et huile de poisson (FHP), destinés à l'exportation. Plusieurs industries sont en concurrence pour les ressources d'anchois, générant des impacts locaux et mondiaux. La nécessité de comprendre ces dynamiques dans un but de recommandations de gestion et de politique de développement durable, a déterminé le développement d'un cadre d'évaluation de la durabilité: 1) caractérisation et modélisation des filières étudiées (avec l'évaluation du cycle de vie et d'autres outils) incluant l'aquaculture locale, 2) calcul d'indicateurs de durabilité (efficacité énergétique, valeur nutritive, performances socio-économiques), et 3) définition et comparaison de scénarios alternatifs d'exploitation. Les scénarios d'exploitation ont été définis en couplant un modèle écosystémique et un modèle de flux de matières: maintien du statu quo (scénario 1), augmentation de la proportion de production pour la CHD (scénario 2), et réduction radicale des captures d'anchois dans le but du rétablissement et de l'exploitation pour la CHD d'autres stocks de poissons (scénario 3). Le scénario 2 a été identifié comme étant le plus durable.Les recommandations de gestion et de politique comprennent l'amélioration: des contrôles de conformité aux mesures de gestion, des conditions sanitaires pour la CHD, des infrastructures pour le débarquement des pêcheries artisanales; le développement d'une chaîne nationale de distribution réfrigérée; et l'attribution de tolérances flexibles pour les rejets de différents processus CHD. / The research performed a sustainability assessment of supply chains of the anchoveta (Engraulis ringens) in Peru. The corresponding fisheries lands 6.5 million t per year, of which <2% is rendered into products for direct human consumption (DHC) and 98% reduced into feed ingredients (fishmeal and fish oil, FMFO), for export. Several industries compete for the anchoveta resources, generating local and global impacts. The need for understanding these dynamics, towards sustainability-improving management and policy recommendations, determined the development of a sustainability assessment framework: 1) characterisation and modelling of the systems under study (with Life Cycle Assessment and other tools) including local aquaculture, 2) calculation of sustainability indicators (i.e. energy efficiency, nutritional value, socio-economic performances), and 3) definition and comparison of alternative exploitation scenarios. Future exploitation scenarios were defined by coupling an ecosystem and a material flow models: continuation of the status quo (Scenario 1), shift towards increased proportion of DHC production (Scenario 2), and radical reduction of the anchoveta harvest in order for other fish stocks to recover and be exploited for DHC (Scenario 3). Scenario 2 was identified as the most sustainable.Management and policy recommendations include improving of: controls for compliance with management measures, sanitary conditions for DHC, landing infrastructure for small- and medium-scale (SMS) fisheries; the development of a national refrigerated distribution chain; and the assignation of flexible tolerances for discards from different DHC processes.

La gestion par éclusées des aménagements hydroélectriques (plus de 150 en France) pour la production d'énergie de pointe engendre de brusques variations de débit sur les cours d'eau et est susceptible d’altérer la composition, l’abondance et la structure des populations de poissons et d’invertébrés, sur de longues distances. Les objectifs de cette thèse ont été (1) de développer une méthode de caractérisation des éclusées au sein des hydrogrammes, ainsi qu'un indicateur synthétique du niveau de perturbation hydrologique, et (2) de progresser dans la définition des mesures de mitigation des impacts des éclusées sur les poissons. A partir de l'analyse de 97 stations et 1575 années de données de débit, les gradients des variations naturelles de débit ont tout d’abord été caractérisés sur 8 gammes entre 5% et 4 fois le débit moyen interannuel (module). Des formules représentant les variations de débit « les plus rapides possibles naturellement » ont été construites en tenant compte du type de variation (hausse ou baisse), de la taille du cours d'eau (via le module) et de la gamme de débit sur laquelle se déroule la variation, pour ensuite discriminer les éclusées des événements naturels. A partir de l'analyse de 80 stations et 491 années de données de débit influencées par les éclusées, une méthode a été mise au point pour repérer au sein des hydrogrammes les éclusées dont les caractéristiques sont au-delà de ce qui peut se rencontrer en hydrologie naturelle, à partir de 3 critères : une amplitude minimale (≥ à 10% du module et ≥ à 20% du débit de base de l’éclusées), un gradient minimal (> au gradient naturel maximal) et une limite haute sur le débit maximum (pour éliminer les événements de crues). Une grande variabilité des régimes d'éclusées du fait de la diversité des aménagements hydroélectriques et des fluctuations des apports hydrologiques et de la demande énergétique, a été constatée et illustrée […]. / Hydropeaking management of hydroelectric facilities (more than 150 in France) generates sudden changes in flow on the river and can affect the composition, the abundance and the structure of fish and invertebrates populations over long distances. The objectives of this thesis were (1) to develop a method for characterizing hydropeaks within hydrograph and a synthetic indicator of hydrological disturbance, and (2) to progress in defining mitigation measures of hydropeaking impacts on fish. From the analysis of 97 stations and 1575 years of flow data, rate of change of natural flow variations have been characterized within 8 ranges between 5% and 4 times the mean inter-annual discharge. Formulas representing the "fastest variations possible naturally" and taking into account the type of change (increase or decrease), the size of the stream (via the mean inter-annual discharge) and the flow range over which the variation takes place have been constructed and then used to discriminate hydropeaks and natural events. From the analysis of 80 stations and 491 years of flow data affected by hydropeaks, a method was developed to identify, within the hydrograph, hydropeaks whose characteristics are beyond what can occur in natural hydrology, using 3 criteria: a minimum range (≥ 10% of the mean inter-annual discharge and ≥ 20% of the hydropeak base flow), a minimal rate of change (> to the maximum natural rate of change) and an upper limit on the maximum flow rate (to remove flood events). A large variation in hydropeaking regimes, due to the diversity of hydroelectric schemes and fluctuations in incoming flow and energy demand, was observed and illustrated […]