SUMMARY Communities of epigeic beetles were studied on two water catchments with the different management in the submontaneous area of Bohemian Forest (South Bohemia, Czechia). The Mlýnský stream catchment was characteristic by high representation of unforested habitats (pastures and mowed meadows), Horský stream by higher proportion of forested habitats and non equal management (plots without management, mowed meadows). The microclimatic characteristics (average temperature, average humidity, average wind speed, average radiation) were measured. The method of pitfall trapping was used for beetle sampling. Beetles species were divided into two groups after its preferences to humidity: hygrophilous species and mesophilous species. The degree of human impact was studied by finding of frequency of species of different ecological groups. 57 species was found in the Mlýnský stream and 33 in the Horský stream. The activity of beetles was about five times higher in Mlýnský stream (511 individuals captured) than in the Horský stream (114 indivuduals found). Ubiquitous species prevail in Mlýnský stream and adaptive species in the Horský stream. Stenotopic species were found in the Mlýnský stream only. These results indicate less human impact in Horský stream than in the Mlýnský stream. Frequency of beetle species with the different requirement on the humidity in communites on studied plots indicates the dominance of mesophilous species in Mlýnský stream in comparison with Horský stream. Frequency of hygrophilous species was about three times higher in Horský stream than in Mlýnský stream. The intensity of management affected the beetle structure mainly on the less forested plot of Mlýnský stream. The structure of communites on plots with more intensive management differs from communities on plots with low management. Hygrophilous species prevail on plots with low management of the Mlýnský stream. The effect of management intensity is not documented in Horský stream with the greater proportion of trees.

Devido à intensificação das atividades industriais e agrícolas, aliada ao grande crescimento urbano e ao aumento exponencial da população no último século, a pressão sobre os recursos hídricos se intensificaram drasticamente. Sendo assim, existe a necessidade de se buscar novas fontes de abastecimento público de água. A captação de água pluvial remonta a milhares de anos, no entanto, por se tratar de uma área onde os estudos são recentes, muitas dúvidas permeiam sobre o método a ser adotado para a implantação de sistemas de captação pluvial, de forma que garanta a saúde de seus usuários. Desta forma, procurando acrescentar cientificamente e analisar novas possibilidades para sistemas de aproveitamento de água pluvial, este projeto objetivou analisar e caracterizar a qualidade da água em diversos pontos em um sistema de captação, armazenamento e utilização de água pluvial, instalado no Laboratório de Ecologia Isotópica do CENA/USP no município de Piracicaba, SP. Foi construído um sistema em escala real contendo cinco recipientes de 100 L para o descarte de primeiras águas, totalizando aproximadamente 3,3 mm de água descartada, com duas cisternas de 5 mil litros cada para armazenar a água captada. Foram coletadas amostras de água em sete pontos do sistema totalizando 36 análises por evento pluviométrico. Os parâmetros analisados foram pH, condutividade elétrica (CE), nitrogênio total (NT), carbono inorgânico dissolvido (DIC), carbono orgânico dissolvido (DOC) e oxigênio dissolvido (OD). As análises de OD foram descontinuadas após a constatação de que o OD, nas diferentes etapas do sistema, não apresentavam diferenças estatísticas devido ao esquema utilizado na montagem do sistema. O pH coletado sempre apresentou valores mais altos que os valores da precipitação, tendendo a diminuir conforme a água captada era descartada atingindo uma média de pH de 6,1 quando a água encontrava-se nas cisternas. A CE e o NT apresentaram valores mais altos que os valores encontrados na precipitação com um decaimento significativo para cada etapa de descarte, assim como apresentaram correlação com a intensidade pluviométrica e o intervalo de estiagem entre eventos pluviométricos. O desvio padrão de CE tendeu a diminuir a cada etapa de descarte, demonstrando que o sistema de descarte atuava como um homogeneizador da água coletada, independente das características pluviométricas. Os parâmetros de DIC também apresentaram valores maiores que os encontrados na água de chuva, assim como apresentaram queda significativa conforme a quantidade de água descartada. Os parâmetros de DOC não apresentaram qualquer correlação com a quantidade de água descartada ou com os parâmetros pluviométricos. Concluiu-se que o sistema de descarte de primeiras águas tem um papel fundamental na qualidade final da água captada. Assim como, que a recomendação da ABNT, de descartar os primeiros 2 mm de chuva, condiz exatamente com o ponto onde se obtêm a melhor qualidade de água com o mínimo de perda. Foi possível constatar que o intervalo de estiagem e a intensidade pluviométrica influenciaram diretamente na qualidade da água que será coletada. / Due to increasing industrial and agricultural activities, coupled with the extensive urban growth and the exponential increase in population in the last century, the pressure on water resources has intensified dramatically. Thus, there is a need to seek new sources of public water supply. The collection of rainwater goes back thousands of years, however, because it is an area where the studies are recent, many questions permeate on the method to be adopted for the implementation of rainwater harvesting systems, as well as ensure health of its users. Thus, seeking to add scientifically and analyze new possibilities for harnessing rainwater systems, this project aims to analyze and characterize water quality at various points in a system of capture, store and use rainwater, at the Laboratory of Isotope Ecology CENA / USP in Piracicaba, SP. A system has been built in real scale with five drums of 100 L for discarding of first waters, totaling approximately 3.3 mm discarted water, with two cisterns of 5000 liters each to store the collected water. Were seven sampling points totaling 36 analyzes per rainfall event. Parameters of pH, electrical conductivity (CE), total nitrogen (TN), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and dissolved oxygen (OD) were analyzed. Analyses of OD were discontinued after the realization that the OD, in the different stages of the system, showed no statistical differences due to the layout of the system. The analyzed pH always showed a higher values than the precipitation and has tended to decrease as the collected water was discarded. Showing an average pH of 6.1 when the water reaches the cistern. The values of EC and NT were higher than the values found in precipitation and tended to decrease gradually in each stage of disposal system of the first water, as also showed a correlated pattern with the rainfall intensity and with the interval between rainfall events. The CE standard deviation tend to decrease at each step of the disposal system of the first water, demonstrating that the disposal system of the first water serves as a homogenizer of water captured, regardless of the rainfall characteristics. The parameters of DIC also showed higher values than those found in rain water, and showed a gradual decrease in each stage of disposal system of the first water. The parameters of DOC showed no correlation with the amount of discarted water or with the rainfall parameters. It was concluded that the disposal system of the first waters has a key role in the final quality of water abstracted. As well as the recommendation of ABNT, of discarding the first 2 mm of rain, matches exactly the point where you can get the best quality water with minimal loss. It was found that the drought period and the rainfall intensity directly influence the quality of water that will be collected.

To guarantee protection of our drinking water, water catchment protections are established. These are divided into three different zones and in the first zone it is most likely that an activity, such as agriculture, will contaminate the water resource. Hence the activities are strongly regulated or banned. The EU communion is working towards a sustained water quality through several directives; Nitrate Directive, Waterframwork directives and Sustainable use of pesticide directive. The main purpose is to regulate the diffuse pollution from agriculture.This thesis is about how Denmark, Germany and France are working towards a sustainable agriculture within water protection areas. Sweden is also discussed but mainly about two different methods applied in Linköpings and Ljungbys municipalties.How the different countries work is mainly the same due to the directives. However, there are some interesting water management methods to observe such as voluntary agreements between water companies and farmers. Moreover, the sustainability perspective is approached in a larger scale where you and I as consumers also contribute via consumer-pays-principle. Therefore, we are, by our demand for water, the problem but also the solution and together we can contribute with good social, economic and ecological conditions for ourselves and the farmer.

Orientador: Marina Sangoi de Oliveira Ilha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-22T06:32:12Z (GMT). No. of bitstreams: 1 Teixeira_PauladeCastro_M.pdf: 3875486 bytes, checksum: b87c55ad6441bb98356e298937ec59f1 (MD5) Previous issue date: 2013 / Resumo: O objetivo principal desta pesquisa é avaliar a qualidade da água drenada por coberturas verdes comparativamente à água escoada por uma cobertura convencional e à água coletada diretamente da atmosfera. Para tanto, foram efetuadas sete coletas de amostras da água drenada por oito coberturas verdes e por uma cobertura cerâmica, todas instaladas em células-teste. Para a análise dos dados, foi empregado o método não paramétrico de Mann-Whitney, com grau de significância de 0,05. Quando analisadas as diferentes coberturas verdes entre si, verifica-se que não existiram diferenças significativas entre os parâmetros físicos e químicos investigados. Além disso, dentre os parâmetros de qualidade de água constantes na normalização brasileira, apenas os valores do pH e da turbidez resultaram inferiores aos valores limites estabelecidos nessa documentação. No caso da cobertura convencional, apenas a cor aparente e os parâmetros microbiológicos não atenderam aos limites estabelecidos. Assim, a água drenada de coberturas verdes deve sofrer tratamento antes do seu uso, porém, verifica-se que não há necessidades diferenciadas de tratamento em relação à água coletada pela cobertura convencional, considerando-se as exigências para a água não potável dos documentos consultados. Em geral, houve melhoria dos parâmetros de qualidade com a idade das coberturas verdes e, a partir disso, propõe-se que o aproveitamento da água ocorra após um período de tempo desde a sua instalação. Por fim, é feita uma proposta de alteração dos parâmetros de qualidade constantes na normalização, de forma a também contemplar a análise da água drenada por coberturas verdes / Abstract: The main objective of this research is to assess the quality of water drained by green roofs compared to water drained by a conventional roof and also water collected directly from the atmosphere. Thus, seven samples were collected from water drained by eight different green roofs and a ceramic cover, all installed in test cells. For data analysis, the method used was the nonparametric Mann-Whitney test, at significance level of 0.05. When the different green roofs were assessed from each other, it seems there were no significant differences among the physical and chemical parameters investigated. Moreover, among the parameters listed in Brazilian standards, only pH and turbidity values resulted lower than the limit values established in this documentation. In the case of conventional roof, only the apparent color and microbiological parameters did not meet the established limits. Thus, water drained from green roofs must undergo treatment before use; however, it does not appear to need different treatment of the water collected from conventional coverage, given the requirements for non-potable water documents consulted. In a general way, there was improvement of water quality parameters as green roofs age, and from this, it is proposed that the use of water occurs after a period of time since its installation. Finally, there is a proposal to amend the quality parameters listed in standardization, in order to also include the analysis of water drained by green roofs / Mestrado / Arquitetura e Construção / Mestra em Engenharia Civil

Alors que les législations françaises et européennes fixent des objectifs ambitieux de protection de la qualité des eaux, les problèmes de pollution par les nitrates et les pesticides utilisés en agriculture persistent en France. Dans ce contexte, l’agriculture biologique qui n’utilise ni produits phytosanitaires ni engrais de synthèse, apparait de plus en plus comme une solution possible pour gérer ces problèmes « à la source ». Un objectif de développement de l’agriculture biologique dans les aires d’alimentation des captages en eau potable a ainsi été inscrit dans la loi Grenelle 1 en 2009. Cette thèse analyse pourquoi et comment l’agriculture biologique s’est trouvée convoquée pour répondre aux problèmes de pollution de l’eau. Elle repose sur une analyse multiniveaux des changements en cours, du niveau global de la conception des politiques publiques jusqu’à celui des agriculteurs, cible principale de cette politique en passant par le niveau territorial de mise en oeuvre de projets associant développement de l’agriculture biologique et protection de la qualité de l’eau. Dans un premier temps, l’évolution des politiques de l’eau et de l’agriculture et des référentiels sectoriels qui les sous-tendent est retracée afin de comprendre comment cette mise en relation entre « agriculture biologique et qualité de l’eau » a pu apparaitre dans l’action publique. Dans un second temps, une analyse de quatre projets territoriaux permet d’étudier comment les acteurs locaux se saisissent de cette convocation et s’engagent dans l’action. Une attention particulière est portée à l’analyse des réseaux d’acteurs impliqués et à celle de la diversité des échelles spatiales auxquelles les projets sont mis en oeuvre. Dans un troisième temps, ce sont les représentations qu’ont les agriculteurs de l’enjeu eau et de l’objectif de développement de l’agriculture biologique qui lui est associé qui sont étudiées. Notre discussion est consacrée aux apports des concepts et des méthodes de la géographie à la compréhension des dynamiques de développement territorialisé de l’agriculture biologique. Enfin, nous ouvrons des perspectives de recherche en termes d’analyse des transitions écologiques de l’agriculture, thématique qui a jusqu’ici été peu investie par les géographes. / The conservation of water resources is a major issue in France because of the increasing problem of water pollution by nitrates and pesticides used in agriculture. In this context, organic farming is seen as a promising solution to this problem because of its Regulation that prohibits the use of chemical fertilisers and pesticides. In 2009, the Grenelle Law stated that priority should be given to organic farming in water catchment areas. This research aims at analysing why and how organic farming has been called in to tackle water pollution problems. It is based on a multi-level analysis. Firstly, the evolution over time of water and agriculture policies (as well as the sectorial paradigms that underly them) is analysed in order to understand how « organic farming » and « the protection of water ressources » came to be associated in public policies. Secondly, a case study is carried out to analyse how local stakeholders take up this idea in setting up projects aimed at developing organic farming toprotect water quality. Particular attention is paid to investigating the stakeholder networks andthe geographical scales at which the projects are implemented. Thirdly, social representations that farmers have of the water question and of organic farming are studied. To conclude, this work examines the contribution of geography to the understanding of an emerging feature: the place-based development of organic farming to tackle environmental problems. It creates new research perspectives related to the analysis of ecological transitions of agriculture, a topic that was so far largely ignored by geographers.

It is my contention that through activating participatory design and community engagement strategies, in conjunction with innovative construction methods that address issues of resource scarcity, the standard of living and level of accessibility to critical resources in impoverished portions of Honduras can be drastically improved. The newly provided model of construction can be done it such a way that it is cost effective in its building method, and provides highly sought after scarce critical resources. This allows participants to allocate more of their finances towards other necessary resources they normally would not be able to acquire. A new community center designed to address the issues of resource scarcity and job opportunities will stand as a first built model with the intent that the methods of construction and innovations employed will be replicated in further applications. The center will be innovative in its construction in such a way that it recognizes local building practices, and brings some new ideas to them allowing for a method of construction that is both improved and more affordable. The center will also take a fresh look at ways the community can address issues of food and water through architectural innovations. The intent is that the success of the center’s combined interventions will encourage local people to replicate the design ideas in their own residential applications. This will improve the quantity of resources available in the community and also start to build a new job market for installing the newly desirable systems. Resource scarcity has wreaked havoc on the typical Honduran villages’ sense of community. Hondurans are in constant competition with their neighbors for scarce critical resources required to sustain life. These resources include, food, water, shelter, and employment opportunities. Violent conflict often arises within communities as individuals compete with their neighbors for the basic necessities required to sustain life. While architecture alone cannot solve all the issues that contribute to the problem of violence, a new center with a program that builds community and provides needed resources stands to potentially curb neighborhood conflict and begin the community healing process. The center stands as not only a replicable model, but also as an immediate community element to bring neighbors back together physically in daily interactions and emotionally in the new resources being provided.

The problem facing the Tlokwe Local Municipality is that it is Constitutional and legislatively obliged to avoid and/or mitigate the impact of potential disasters within its boundaries, through the effective management of potential disaster risks and disasters. The lack of effective risk management tools is especially concerning in the context of the water catchment management of the Mooi River, which is the main water supply of the Tlokwe local Municipality. The Mooi River is exposed to many potential catchment related hazards that could affect the municipality of which the origins are both anthropogenic and natural. Although, many of the impacts on the catchment arise beyond the boundaries and the control of the municipality, this does not relieve the municipality from the responsibility to develop tools to manage the risks. The aim of the study is to assist in addressing the above stated problem through establishing the requirements for a conceptual model for an effective spatial information system that will assist the municipality in effectively managing the potential disaster risks and disasters that may arise in the Mooi River Catchment area that could impact on the Tlokwe Local Municiaplity. The aim gives rise to three-research questions that are formulated as research objectives that are used to identify the conceptual model requirements. The first is to identify and conceptualise the constitutional and legislative obligations in respect of disaster risk management in general and specifically those governing the disaster disk management in the water catchment area for the Mooi River. The study of this objective not only highlight the constitutional and legal obligations that the local municipality is subject to, but provides legislatives remedies that the local municipality can utilise to assist with disaster risks reduction. The second is to identify and conceptualise the generic hazards that are related to water catchment areas (including the related groundwater compartments) and those specific in the Mooi River catchment area. In this section, potential anthropogenic and natural hazards are listed, a methodology for risk and vulnerability analyses is provided, and a concise study of quaternary catchment C23D is provided. The third is to identify and conceptualize the requirements for an effective conceptual model of GIS for Disaster Risk Management in the Tlokwe Local Municipality. An overview of a GIS is provided. The essential components of a generic information system namely, people, software, hardware, procedures and processes, data and telecommunications or networks are discussed. The information and system requirements cumulating from the analyses of the three research questions, serve as the drivers of the goal, outcomes and transformation process of the system as well as the requirements for the conceptual model. In this section: a comparison of the Systems Development Life Cycle (SDLC), Framework for Applied Systems Thinking (FAST), problem solving and the phases addressed in this study; the identification of the conceptual model requirements; and a concise systems conceptualisation of an effective GIS is provided. As the, mini-dissertation focuses on the needs for a conceptual model, the additional activities required before the system can be implemented are identified and formulated as recommendation that provide the opportunity for future research. / M Development and Management, North-West University, Potchefstroom Campus, 2014

The problem facing the Tlokwe Local Municipality is that it is Constitutional and legislatively obliged to avoid and/or mitigate the impact of potential disasters within its boundaries, through the effective management of potential disaster risks and disasters. The lack of effective risk management tools is especially concerning in the context of the water catchment management of the Mooi River, which is the main water supply of the Tlokwe local Municipality. The Mooi River is exposed to many potential catchment related hazards that could affect the municipality of which the origins are both anthropogenic and natural. Although, many of the impacts on the catchment arise beyond the boundaries and the control of the municipality, this does not relieve the municipality from the responsibility to develop tools to manage the risks. The aim of the study is to assist in addressing the above stated problem through establishing the requirements for a conceptual model for an effective spatial information system that will assist the municipality in effectively managing the potential disaster risks and disasters that may arise in the Mooi River Catchment area that could impact on the Tlokwe Local Municiaplity. The aim gives rise to three-research questions that are formulated as research objectives that are used to identify the conceptual model requirements. The first is to identify and conceptualise the constitutional and legislative obligations in respect of disaster risk management in general and specifically those governing the disaster disk management in the water catchment area for the Mooi River. The study of this objective not only highlight the constitutional and legal obligations that the local municipality is subject to, but provides legislatives remedies that the local municipality can utilise to assist with disaster risks reduction. The second is to identify and conceptualise the generic hazards that are related to water catchment areas (including the related groundwater compartments) and those specific in the Mooi River catchment area. In this section, potential anthropogenic and natural hazards are listed, a methodology for risk and vulnerability analyses is provided, and a concise study of quaternary catchment C23D is provided. The third is to identify and conceptualize the requirements for an effective conceptual model of GIS for Disaster Risk Management in the Tlokwe Local Municipality. An overview of a GIS is provided. The essential components of a generic information system namely, people, software, hardware, procedures and processes, data and telecommunications or networks are discussed. The information and system requirements cumulating from the analyses of the three research questions, serve as the drivers of the goal, outcomes and transformation process of the system as well as the requirements for the conceptual model. In this section: a comparison of the Systems Development Life Cycle (SDLC), Framework for Applied Systems Thinking (FAST), problem solving and the phases addressed in this study; the identification of the conceptual model requirements; and a concise systems conceptualisation of an effective GIS is provided. As the, mini-dissertation focuses on the needs for a conceptual model, the additional activities required before the system can be implemented are identified and formulated as recommendation that provide the opportunity for future research. / M Development and Management, North-West University, Potchefstroom Campus, 2014

En réponse aux réglementations environnementales récentes incitant à une gestion préventive de la qualité de l'eau, l'agriculture biologique (AB) constitue une des solutions globales préconisée pour cette gestion préventive. L'objectif de cette thèse est d'étudier les transitions des exploitations agricoles vers l'AB dans les territoires, en prenant les aires d'alimentation de captages (AAC) en Île-de-France comme cas d'étude. En nous inscrivant en agronomie des territoires, nous développons une interface disciplinaire avec la géographie et analysons ces transitions sous l'angle des interactions entre systèmes techniques et de commercialisation à différentes échelles territoriales. Des enquêtes ont été réalisées auprès d'agriculteurs franciliens en systèmes de grandes cultures et de maraîchage et auprès d'opérateurs des filières agricoles. Des « études AAC » en cours ont également été étudiées. Nous avons abordé dans un premier temps les potentialités et les modalités de transition des exploitations vers l'AB en développant des méthodes pour évaluer leur proximité technique à l'AB et l'ampleur des sauts techniques et commerciaux qu'elles auraient à réaliser dans une situation de conversion. Parallèlement, l'analyse des stratégies techniques et commerciales des exploitations biologiques a permis d'aboutir à différents modèles biologiques. Nous avons ensuite montré que les opportunités territoriales de commercialisation jouent sur les possibilités d'évolution des exploitations vers l'AB. Enfin, la pertinence de l'échelle AAC pour engager un développement territorialisé de l'AB a été remise en cause. La complexité de mise en oeuvre de cet objectif a été montrée en lien avec la superposition de territoires de différentes natures. Ce travail contribue à la compréhension des obstacles à l'insertion effective de l'AB dans les territoires à enjeu eau potable. / Organic farming is one of the global solutions recommended in response to recent environmental regulations for preventive management of water quality. The aim of this thesis is to study the transition of farms towards organic farming in specific territories, based on the case of water catchment areas in Ile-de-France. From an agronomy of territories perspective, I develop a disciplinary interface with geography, and analyze these transitions from the viewpoint of interactions between technical and commercialization systems on various territorial scales. My research has included surveys on large-scale farmers and market gardeners in the Ile-de-France region, and on operators of agricultural supply chains. I have also examined "water catchment areas studies" under way. I first consider the potentialities and modalities of farms' transition to organic farming, by developing methods to evaluate their technical proximity to organic farming and the size of the technical and commercial leaps that they would have to make in a situation of conversion. In parallel, an analysis of the technical and commercial strategies of organic farms enables me to produce various biological models. I then show that the territorial opportunities of commercialization impact on organic farms' possibilities to evolve. Finally, the relevance of the water catchment area scale for engaging in territorialized development of organic farming is called into question. The complexity of the implementation of this objective is shown in relation to the superposition of territories of different natures. This work contributes to the understanding of obstacles to the effective introduction of organic farming in territories where drinking water is an issue.

Face à la pollution généralisée des masses d’eau souterraines par les nitrates et les pesticides, l’agriculture biologique (AB) est présentée comme un outil pertinent pour la reconquête de la qualité des eaux sur les aires d’alimentation de captage (AAC). Ce travail vise à mieux définir l’opportunité d’un développement de l’AB sur des zones à enjeu eau. L’objectif de la thèse est d’évaluer conjointement la faisabilité des conversions sur les exploitations de l’AAC et l’efficacité de ces conversions par rapport aux enjeux de reconquête de la qualité de l’eau.Etudier l’opportunité d’un développement de l’AB à l’échelle territoriale suppose d’instruire la diversité des exploitations et des profils d’agriculteurs sur la zone à enjeu eau. Pour être en mesure de tester l’opportunité des conversions, une méthode typologique permettant d’analyser conjointement la variabilité actuelle des pressions sur les zones à enjeu eau et la propension des agriculteurs conventionnels à la conversion est nécessaire.Pour produire cette typologie, nous avons développé une méthode innovante d’analyse compréhensive des pratiques, centrée sur les principes d’action à l’origine des systèmes de culture. Les principes d’action correspondent à des méta-raisonnements à l’origine de l’organisation concrète des pratiques agricoles sur le territoire d’exploitation. Par l’analyse conjointe du discours des agriculteurs et de la variabilité des règles de décision, nous avons élaboré des typologies basées sur les postures techniques des agriculteurs pour i) identifier des principes d’action associés aux pratiques à risque et ii) dégager des proximités éventuelles entre agriculteurs biologiques et agriculteurs conventionnels. La méthode a été testée sur deux territoires à enjeu eau en Rhône-Alpes, sur lesquels des entretiens semi-directifs ont été réalisés auprès d’exploitants conventionnels et biologiques.Cinq principes d’action génériques à l’origine de l’organisation de l’assolement et cinq principes d’action génériques à l’origine des pratiques culturales ont été dégagés. A partir des différents principes d’action, des typologies des postures techniques ont été produites sur les deux terrains. Les pressions à l’origine de la lixiviation des nitrates et des pesticides ont été évaluées et spatialisées via le recours à des indicateurs agro-environnementaux. Nous avons démontré que la variabilité forte des indicateurs et leur distribution spatiale sur les AAC étaient liées à la diversité des postures techniques entre agriculteurs.Nous avons comparé les principes d’action mobilisés par les agriculteurs conventionnels et les agriculteurs biologiques « références » présents sur les zones à enjeu eau. Par l’étude des spécificités des postures techniques en AB, trois critères de propension à la conversion ont été identifiés. Plusieurs degrés de propension à la conversion ont été dégagés parmi les agriculteurs conventionnels des deux territoires.L’analyse croisée des degrés de propension à la conversion et des différentiels de pressions entre systèmes conventionnels et biologiques nous a permis d’évaluer l’opportunité d’un développement de l’AB sur les deux territoires. Nos résultats ont mis en évidence des niveaux de pression limités quant à la lixiviation des nitrates sur les systèmes biologiques : un développement exhaustif de l’AB à l’échelle des deux AAC entrainerait potentiellement une réduction forte de la lixiviation des nitrates. Néanmoins, l’opportunité d’un tel développement doit être relativisée. Les agriculteurs présentant une propension réelle ou forte à la conversion sont minoritaires sur les AAC. Ensuite, le différentiel des pressions entre systèmes conventionnels et systèmes biologiques diminue à mesure que la propension à la conversion augmente. Pour envisager une diminution forte des pressions sur les zones à enjeu eau, la conversion devrait concerner des exploitants pour lesquels cette conversion est difficilement envisageable à moyen terme. / Many problems with nitrate and pesticide contamination from agriculture exist in European drinking water catchments. In France, a new mitigation approach aims at preventing water quality degradation in explicitly targeting agricultural non-point source pollutions associated with leaching of nitrates and pesticides. This work aims at assessing the opportunity to develop organic farming in water catchment areas in order to reduce nitrate and pesticide leaching from root zone. The objective was to analyze both i) feasibility of conversions to organic farming on farms concerned by water preservation and ii) the potential impacts of these conversions in terms of nitrate and pesticide leaching reduction.To explore the potential contribution of organic farming in water catchment areas, we develop an innovative typology approach to characterize farmers’ conceptions and strategies related to cropping systems’ organization on the farm territory. Our method was tested in two French water catchment areas characterized by diversified production systems, where semi-structured interviews were carried out with conventional and organic farmers. Resulting typologies of farmers were used to assess leaching risks variability related with current cropping systems and to identify potential similarities between conventional and organic farmers’ conceptions. Nitrate and pesticide leaching risks for cropping systems were assessed and spatialized by using four agro-environmental indicators. Our results show major variations for all indicators at both study sites, for example N-surpluses which range from -105 to 192 kg N ha-1 year-1. These variations are deeply related with diversity of farmers’ conceptions summarized in typologies. To assess proximity of conventional farmers to organic farming, we used typologies to compare conceptions related to organization of cropping systems between conventional and organic farmers. By analyzing specificities of organic farmers’ conceptions, we determined three main criteria of proximity to organic farming; these criteria were then used to identify various degrees of proximity to organic farming among conventional farmers in the catchment areas.To assess potential contribution of organic farming to water preservation in catchment areas, we firstly compared nitrate leaching risks between conventional and organic cropping systems. Our results reveal low leaching risks from organic systems, characterized by reduced N-surpluses and lower bare soils frequencies in autumn. According to these results, massive development of organic farming should decrease nitrate leaching in our two water catchment areas. However, analysis of similarities between conventional and organic farmers’ conceptions shows that a majority of farmers are characterized by a low level of proximity to organic farming. Moreover, the farmers who show strongest similarities with organic farmers’ conceptions are already those with low leaching risks cropping systems. To significantly lower nitrate leaching risks, conversions should concern conventional farmers with low degree of proximity to organic farming.