Cities within California are beginning to incorporate urban agriculture into their land use designations. Prompted by residents and local organizations, cities are hoping to capture the benefits that urban agriculture provides. Research has shown that urban agriculture renews and beautifies neighborhoods, provides healthy food choices, increases public health, has the potential to help with stormwater runoff, creates jobs, and fosters community. In the last few years, several California cities have made headlines as they have adopted new zoning codes that include urban agriculture. In reviewing these new zoning codes and exploring the topic of urban agriculture, it became evident that just because an urban farm was small, organic and provided certain benefits that it was not free from impacting its surroundings. As more urban agricultural ventures are established within cities, planners have to carefully consider their effect. One such impact could be stormwater pollution. There is insufficient research to determine whether there is a relationship between urban agriculture and stormwater, however, studies on conventional agriculture and urban landscaping (mainly urban lawns) show that each of these areas pollute the local water bodies with sediment, chemicals, and nutrients. Is urban agriculture different? This thesis utilizes two case studies within California, the City of Oakland and the City of San Diego, to examine the similarities and differences between each city’s urban agriculture ordinances and evaluate whether or not the cities have adjusted stormwater requirements in parallel with these ordinances. Interview responses and site visits in each city were analyzed and compared to expound upon the approaches each city engaged. Using the collected data and analysis as a base, a set of guidelines was created for managing stormwater runoff from urban agriculture.

La recherche qui suit porte sur l’expérience du jardinage communautaire à Montréal à partir de l’exemple de l’un des arrondissements. Au cours des dernières années, à l’échelle globale, la popularité des jardins communautaires est allée en grandissant. Comment interpréter cela à partir du point de vue des participants? Quelle est l’expérience vécue par les jardiniers communautaires et quelle signification accordent-ils à ces pratiques sociales? Afin de répondre à ces questions, j’ai fait appel à une démarche qualitative, combinant l’observation et entretiens en profondeur avec des participants. Les résultats de l’étude découlent de 30 entretiens semi-directifs. Des participants avec des profils sociaux divers ont été recrutés. En faisant appel à la théorie ancrée, la recherche met en lumière des contextes spécifiques à partir desquels les jardiniers communautaires fournissent des significations à leur engagement dans ce type de jardinage. Considérée à partir de trois dimensions – économique, sociale et culturelle – cette étude met en lumière le fait que les significations que les acteurs accordent à leurs pratiques dépendent du contexte, mais découlent aussi de leur subjectivité. Ressort aussi l’importance de la dimension émotionnelle. Le jardinage communautaire est décrit sous l’angle d’une pratique transformatrice – en convergence avec d’autres formes d’action collective – qui permet aux citoyens en tant que jardiniers de mieux faire face aux défis de la vie quotidienne, que ce soit sur le plan financier, social, culturel ou environnemental. Par le biais du jardinage, les participants soutiennent qu’ils approfondissent leur identité personnelle, tout en construisant de nouvelles relations avec les autres ainsi qu’avec la nature. La recherche confirme qu’en ce qui concerne l’expérience subjective de jardinage, les participants parlent de retombées positives. / The present research addresses the subjectivity of the community gardening experience in the case of a Montreal borough. Community gardens have regained popularity worldwide. How to interpret this phenomenon from the perspective of participants? And how do they experience (community) gardening and make sense of their social practices? To answer these questions, this study takes a qualitative approach that combines observations and in-depth interviews. The findings drawn from this study are based mainly on 30 semi-structured interviews. Participants from diverse social strata were recruited. Guided by grounded theory, this research stresses the specific contexts under which community gardeners generate meanings from their community gardening experience. Examined from three dimensions – economic, social, and cultural – this study reveals that meanings and significance are context-sensitive, personalized, and fluid. The emotional dimension emerges as of particular importance. Community gardening is viewed as a transformative practice – converging with diverse forms of collective action – that allows citizen gardeners to address everyday life challenges, whether financial, social, cultural, or environmental. Through gardening, participants claim that they are reconnecting with themselves, with other people, and with nature. This research confirms that with respect to the subjective experience of gardening, participants generally claim positive outcomes.

RESUME :<p>Comme la plupart des villes africaines, Yaoundé, capitale du Cameroun, est confrontée aux phénomènes d’urbanisation croissante. Cette urbanisation rapide n’est pas accompagnée d’une croissance économique. En fait, le pouvoir d’achat extrêmement bas, le chômage, le sous-emploi, la pauvreté, voire la misère, ont amené une frange importante de la population à inventer de nouvelles solutions pour s’assurer un revenu. C’est alors qu’apparaît le phénomène d’agriculture urbaine et périurbaine. La caractérisation de cette agriculture a mis en évidence une interaction entre les catégories d’acteurs, les types d’espaces, les types de cultures, les produits obtenus et les revenus moyens générés. Il ressort de l’analyse des résultats que cette forme d’agriculture emploie près de 2000 personnes, pour la plupart des jeunes et, surtout, des femmes, dont la moyenne d’âge est de 35 ans. C’est une activité basée principalement dans les bas-fonds marécageux, le bas des pentes, les abords des routes avec une forte pression sur l’espace. Les cultures sont diversifiées et sont à dominance maraîchère, vivrière et floricole. Elles varient en fonction des trois espaces étudiés, à savoir l’auréole urbaine, la zone périurbaine et l’hinterland rural. <p>L’analyse du système de commercialisation a mis en évidence trois types de circuits à travers lesquels les produits transitent des producteurs aux consommateurs. Ce sont notamment les circuits longs, les circuits courts et les circuits directs. Dans ces circuits de commercialisation, la régulation du marché se réalise au niveau de tous les intervenants. Cela signifie que les prix des produits ne sont pas fixés d’avance, mais varient en fonction de la demande. En ce qui concerne la rentabilité, l’analyse sur les comptes d’exploitation des cultures de céleri, de ndolé et de morelle noire indique que cette agriculture est rentable avec un gain moyen journalier de près de trois euros pour les producteurs. C’est la raison pour laquelle certains maraîchers estiment qu’à la place d’un travail salarial de près de 75euros / mois, ils préfèrent rester dans leur jardin. <p><p>Cependant, aucun cadre juridique et réglementaire lié à l’exercice de cette activité n’est disponible. Aucun article de loi ne l’autorise. Nous avons noté également de nombreuses autres contraintes liées à l’organisation des producteurs, aux pratiques, à la structuration et la mise en marché des produits. Ces résultats ont alors d’importantes implications quant à la compréhension des interactions entre les agriculteurs en ville et le monde politique de Yaoundé. Les fonctions multiples de cette activité tel que l’emploi pour les jeunes, les revenus substantiels pour les couches des populations les plus vulnérables, la gestion des déchets urbains et la beauté du paysage étant autant d’attraits qui concourent à son encouragement. <p>Les stratégies qui visent à susciter l’implication des producteurs urbains dans le développement de la ville de Yaoundé ont été mises en œuvre à travers la CAUPA (Coalition pour la promotion de l’agriculture urbaine et périurbaine en Afrique). L’intégration de ces stratégies dans les schémas directeurs d’aménagements urbains, pourrait contribuer à concilier les défis d'une amélioration du bien-être des populations en quête de survie. Cette thèse met en évidence la nécessité d’une médiation entre les différentes catégories d’acteurs pour une agriculture urbaine et périurbaine de qualité. Les résultats pourront permettre aux décideurs et administrateurs des villes de disposer d‘informations utiles sur l’importance de cette forme d’agriculture qui est, non seulement montante, mais aussi controversée. <p>SUMMARY:<p>As in most African cities, Yaounde, the capital city of Cameroon, is faced with the phenomenon of urbanization. This leads to socio-economic problems especially in food supply and acquisition of basic necessities. The extremely low purchasing power, unemployment, underemployment, poverty - say misery, brought a significant proportion of the population to invent new solutions to ensure basic income through urban and peri-urban agriculture. The characterization of this agricultural system highlights the interaction between various stakeholders, types of spaces and crops, productivity and average revenue generated. Results show that this agricultural system has generated employment for about 2000 people, mainly youths and especially women, with 35 years average age. The activity is based mainly in lowland floody zones, low slope, landscaping roads with increase land pressure. Vegetables, gardening and flowers are dominant diversified crops noticed in the area. These crops vary from urban, peri-urban and rural areas, three landscape which were studied. <p><p>The analysis of the marketing chain show three main types of distribution chains through which products pass from producers to consumers. These include long distribution, short distribution and direct channel. In these channels, the regulation of the market is achieved at the level of all stakeholders. This means that the prices of the products are therefore fixed in advance, and also are functions of demand. Regarding profitability, the analysis on the farmer’s accounts of Celery, Bitter leaf and Black nightshade indicates that this agriculture is profitable with an average daily gain of almost 3 euro per producers. That's why some gardeners believes that instead of a salary of almost 75 euro per month, they prefer to stay in their farm. <p><p>However, no legal and regulatory framework related to this activity is available in the case of Yaounde. Also, there are many other constraints related to the organization of producers, practices, structuring and implementation of products in the markets. These results have important implications to the understanding of the interaction between farmers and policy makers. The multiple functions of this activity such as youth employment, income for substantial segments of the most vulnerable populations, urban waste management and the beautification of the landscape is as much attraction that contribute to its promotion. <p><p>A strategy to encourage the implication of urban producers in the development of the city of Yaounde has been implemented through CAUPA. The integration of these strategies in urban planners, could help for the challenges of improving people’s welfare. Subsequently, this thesis brings forth the need for a mediation between different stakeholders and contributes to good quality of peri-urban agriculture. The results can therefore enable decision-makers and policy to provide useful information on the importance of this form of agriculture which is not only rising, but also controversial.<p><p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished

Wetlands are fragile ecosystems that deliver a wide range of environmental and ecosystem services that contribute to human well-being. This fragility has seen a number of wetlands succumb to degradations and loss arising from different causes. The positive contribution of wetlands to various ecosystems and the increasing rate of their degradation and loss has been a cause for concern to different stakeholders for a long time. One of the landmark indications of this concern is the constitution of the Ramsar Convention that was held in Iran in 1971 with the objective of addressing concerns regarding to wetland degradation and loss. Among the competing land uses resulting in wetlands loss and degradation could be listed urban agriculture, industrial development and housing. The research sought to assess the extent of wetland degradation with respect to housing developments in Harare, Zimbabwe. The dilemma as to why and how wetlands were being degraded was an issue of concern. The research sought to determine whether abatement or mitigation measures were in place to address the challenges Associated with wetlands loss and degradation. The subsequent growth of developments, their associated activities and possible intervention measures had to be thoroughly assessed. The administration of questionnaires and conducting of interviews was done to solicit data from the respondents. Collected data was analyzed through the Statistical Package for Social Scientists. Further to this, Google satellite imagery was used in the mapping of the Belvedere North and Epworth suburbs. Disturbed and undisturbed portions of the wetlands were analyzed by Geographical Information System software. Direct observation of the wetland area was used to examine existing natural features. To determine extent of pollution, water samples were collected in the wetlands and submitted to the laboratory for analysis. Analysis of selected chemical and physical parameters was carried out in the laboratory using selected methods. The research made two important and broad findings. First, both the Belvedere North and Epworth wetlands have been severely degraded by anthropogenic activities with housing developments and urban agriculture as the major contributors of this degradation. The development of residential properties in the wetlands is a result of a high demand for residential space in Harare. Whereas housing developments in Belvedere are formal and planned, developments in Epworth were informal and haphazard. With no formal planning, the Epworth wetlands have been severely impacted by water and sand extraction as well as contamination of underground water by pit-latrines that are common in these informal settlements. Second, the research also found that wetland degradation was closely associated with the lack of clear wetland policies both at national and local levels. The laboratory results showed that the water in Epworth was more polluted than the water in Belvedere. The measure of pollutants in Epworth was higher due to the activities being carried out as compared to Belvedere. Measures of Dissolved Oxygen, Total Dissolved Substances and conductivity increased from October to March in Epworth. Of note is the measure of Dissolved Oxygen that increased between October and March with a mean of 7.9 and 2.5 respectively. Total nitrogen and total phosphate also increased significantly in midstream and downstream sections. In essence, averages of 0.01 in October and 0.04 in March were recorded respectively for total nitrogen. The study concludes that an integrated land use approach has the potential of minimizing wetland loss and degradation. This is possible through the formulation and implementation of a comprehensive policy involving all relevant stakeholders. This will ensure a coherent decision making process. In as much as integrated land use planning and policy formulation are potential approaches to wetland sustainability, the drive to implement policy by policy makers concerning wetlands has to be explored. As ignorance concerning the ecological importance of wetlands exists in some cases, it is critical to consider wetland benefits above other competing developments such as housing and urban agriculture. This can be achieved through merging interrelated disciplines with the idea of integrating wetland information. For instance, deriving engineering solutions could promote development yet preserving wetlands. It is also suggested that environmental impact assessments, as planning tools should be carried out simultaneously with the town planning aspect. If given to proper planning, wetlands have a huge chance of survival. / Environmental Sciences / M.Sc. (Environmental Management)

Thesis (MPhil)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Stellenbosch University was approached to assist with developing a techno-financial model for an urban freshwater aquaculture system in Philippi, Cape Town. Rapidly growing urban areas are predominantly becoming concentrated zones for malnutrition and poverty which require attention. Having enough food to eat does not mean that a family is food secure, the problem is usually associated with the lack of access to nutritious food. Fish is seen as an extremely healthy food which has the potential to effectively support food security and alleviate malnutrition. Aquaculture is identified as a largely underdeveloped sector in South Africa. It is currently undergoing rapid transition, being promoted by government as an industry that has potential to develop and create jobs, provide food security and grow the South African economy. Aquaponics- a method to integrate aquaculture with growing crops in a symbiotic system is a highly resource efficient closed-integrated food producing technology which has the potential to benefit from South African biosecurity regulations and climate-geographic characteristics. It is viewed as an effective food production alternative to deal with the challenges of declining high quality freshwater resources and available arable land. Training and capacity building is important for the development of aquaponic technology. This study explores and identifies the advantages aquaponic technology development would have in South Africa. The study has reviewed and assessed the fundamental principles for aquaculture production and management required for aquaponic systems development and management. A practical case study identifies the daily challenges and design parameters of aquaponic systems. The study is concluded with a techno-financial project proposal which shows how aquaponic systems can be planned. / AFRIKAANSE OPSOMMING: Universiteit Stellenbosch was genader om 'n tegno-finansiele model to ontwikkel vir 'n stedelike akwakultuur plaas in Philippi, Kaapstad. The tempo waarteen die stedelike areas groei ontwikkel kommerwekkende uitdagings soos wanvoeding en armoede. In hierdie studie is vis geindentifiseer as 'n uiters voedsame aanvulling in die dieet van Suid Afrikaners. Akwakultuur is grootliks agter in terme van ontwikkeling. Dit word beskou as 'n sektor wat groot potensiaal inhou vir Suid Afrika se eknomiese groei, werkskepping en voedselsekuriteit. Akwaponika is die hersirkulerende integrasie van akwakultuur en hidroponika. Akwaponika hou groot voordele in terme van Suid Afrika se biosekuriteit regulasies and geografiese eienskappe en is 'n effektiewe manier om gebruikte akwakultuur te suiwer. Opleiding en beplanning word gesien as 'n fundamentele benadering tot suskesvolle akwaponika ontwikkeling. Hierdie studie bestudeer die Suid Afrikaanse omgewing en potensiaal vir akwaponika ontwikkeling. Die fundamentele beginsels van akwakultuur en hidroponika bestuur en produksie is saamgesit wat beskou word as die aanbevele manier om akwaponika te bestuur. 'n Praktiese gevallestudie toon die daaglikse uitdagings aan en gee raad oor daaglikse bestuur van akwaponika stelsels. Die studie word afgesluit met 'n tegno-finansiele model wat wys hoe om 'n akwaponika sisteem te beplan.

Wirtschaftliche Prozesse sind in Zeiten der Globalisierung zunehmend komplexer. Immer mehr Akteure sind an der Erstellung eines Produktes von der Konzeption bis zur Konsumption durch die Verbraucher beteiligt. Innovationen im Bereich von I&K-Technologien oder im Verkehr, sinkende Transport- und Transaktionskosten sowie organisatorische Neuerungen ermöglichen eine räumliche Trennung einzelner Produktionsschritte der Wertschöpfungskette. Es entstehen Unternehmensnetzwerke, die nicht auf räumlicher, sondern organisatorischer Nähe basieren. Die Verflechtungen zwischen den Akteuren können in Wertschöpfungsketten abgebildet werden. Allgemeine Betrachtungen zu Wertschöpfungsketten, Modelle zu Warenketten und zum politisch-ökonomischen Zusammenhang in der Nahrungsmittelproduktion bilden die theoretische Grundlage dieser Arbeit. In Kuba haben sich die Produktions- und Warenketten vor dem Hintergrund der binnen- und außenwirtschaftlichen Krise in den Jahren 1989/90 stark verändert. In der vorliegenden Arbeit werden ausgehend von den Entwicklungen in der Lebensmittelwirtschaft Kubas, die Verflechtungen zwischen den Akteuren des Agrarsektors, der Lebensmittelindustrie und des Einzelhandels untersucht. Die empirische Analyse umfasste darüber hinaus Betrachtungen zu den Transport- und Distributionsvorgänge innerhalb der Warenketten, den Macht- und Kontrolleinflüssen einzelner Akteure und zu den räumlichen Strukturen. Durch die qualitative Untersuchung konnten im Ergebnis fünf verschiedene Typen von Produktions- und Warenketten festgestellt werden. Die erste Gruppe repräsentiert industrielle Warenketten, die für den rationierten Einzelhandel produzieren. Die zweite Gruppe umfasst die industriellen Warenketten, die auf das Devisensegment orientiert sind. Die dritte Gruppe bildet jene Warenketten ab, bei denen das Segment der industriellen Produktion fehlt. Sie sind auf die direkte Versorgung der Bevölkerung mit frischen Agrarprodukten ausgerichtet. Gerade die Produktions- und Warenketten der dritten Gruppe stellen eine besondere Form dar. Wefen der ökonomischen Krise und den Transportschwierigkeiten in Kuba haben sich seit 1994 lokale Wirtschaftskreisläufe herausgebildet. Sie stellen die kürzesten Produktions- und Warenketten der Insel dar. / In times of globalisation economic processes become increasingly complex. More and more actors are involved in the production - starting at the design and ending at the consumption - of a product. Innovation in Information and Communication Technology or transport, decreasing transportation and transaction costs as well as process innovations facilitate a spatial separation of individual production steps of the value-added chains in different locations. Therefore new business networks develop which are not based spatial, but organisational proximity. Connections between the different actors can be shown in value-added chains. The theoretical frame for this dissertation are general approaches on value-added chains, models for commodity chains and political-economic relations in food industry. In Cuba commodity chains have changed radically due to the interior and exterior economic crisis in 1989/90. This work, based on the development of the Cuban food industry, studies the material and immaterial connections between the actors of the agricultural sector, food industry and retail trade. The empirical analysis also includes observations on transport and distribution processes within commodity chains, power and control impact by specific economic and institutional actors and spatial structures of commodity chains. Through the qualitative analysis, using the example of the tomato, five different types of commodity chains were identified. The first group represents industrial commodity chains, which produce for the state rationed retail trade. The second group includes industrial commodity chains, which focus on the currency segment. The third group sums up those commodity chains which lack the industrial segment. They focus on the population’s direct supply with fresh agricultural products. Especially the third group’s commodity chains represent a special type. Due to the economic crisis and the connected transportation problems, local economic cycles evolved in Cuba since 1994. Opposite to the industrial commodity chains they represent the shortest commodity chains on the island and therefore differ from the first and second group of commodity chains.

Wetlands are fragile ecosystems that deliver a wide range of environmental and ecosystem services that contribute to human well-being. This fragility has seen a number of wetlands succumb to degradations and loss arising from different causes. The positive contribution of wetlands to various ecosystems and the increasing rate of their degradation and loss has been a cause for concern to different stakeholders for a long time. One of the landmark indications of this concern is the constitution of the Ramsar Convention that was held in Iran in 1971 with the objective of addressing concerns regarding to wetland degradation and loss. Among the competing land uses resulting in wetlands loss and degradation could be listed urban agriculture, industrial development and housing. The research sought to assess the extent of wetland degradation with respect to housing developments in Harare, Zimbabwe. The dilemma as to why and how wetlands were being degraded was an issue of concern. The research sought to determine whether abatement or mitigation measures were in place to address the challenges Associated with wetlands loss and degradation. The subsequent growth of developments, their associated activities and possible intervention measures had to be thoroughly assessed. The administration of questionnaires and conducting of interviews was done to solicit data from the respondents. Collected data was analyzed through the Statistical Package for Social Scientists. Further to this, Google satellite imagery was used in the mapping of the Belvedere North and Epworth suburbs. Disturbed and undisturbed portions of the wetlands were analyzed by Geographical Information System software. Direct observation of the wetland area was used to examine existing natural features. To determine extent of pollution, water samples were collected in the wetlands and submitted to the laboratory for analysis. Analysis of selected chemical and physical parameters was carried out in the laboratory using selected methods. The research made two important and broad findings. First, both the Belvedere North and Epworth wetlands have been severely degraded by anthropogenic activities with housing developments and urban agriculture as the major contributors of this degradation. The development of residential properties in the wetlands is a result of a high demand for residential space in Harare. Whereas housing developments in Belvedere are formal and planned, developments in Epworth were informal and haphazard. With no formal planning, the Epworth wetlands have been severely impacted by water and sand extraction as well as contamination of underground water by pit-latrines that are common in these informal settlements. Second, the research also found that wetland degradation was closely associated with the lack of clear wetland policies both at national and local levels. The laboratory results showed that the water in Epworth was more polluted than the water in Belvedere. The measure of pollutants in Epworth was higher due to the activities being carried out as compared to Belvedere. Measures of Dissolved Oxygen, Total Dissolved Substances and conductivity increased from October to March in Epworth. Of note is the measure of Dissolved Oxygen that increased between October and March with a mean of 7.9 and 2.5 respectively. Total nitrogen and total phosphate also increased significantly in midstream and downstream sections. In essence, averages of 0.01 in October and 0.04 in March were recorded respectively for total nitrogen. The study concludes that an integrated land use approach has the potential of minimizing wetland loss and degradation. This is possible through the formulation and implementation of a comprehensive policy involving all relevant stakeholders. This will ensure a coherent decision making process. In as much as integrated land use planning and policy formulation are potential approaches to wetland sustainability, the drive to implement policy by policy makers concerning wetlands has to be explored. As ignorance concerning the ecological importance of wetlands exists in some cases, it is critical to consider wetland benefits above other competing developments such as housing and urban agriculture. This can be achieved through merging interrelated disciplines with the idea of integrating wetland information. For instance, deriving engineering solutions could promote development yet preserving wetlands. It is also suggested that environmental impact assessments, as planning tools should be carried out simultaneously with the town planning aspect. If given to proper planning, wetlands have a huge chance of survival. / Environmental Sciences / M. Sc. (Environmental Management)

Different challenges arising from increasingly uncertain and unpredictable environmental and economicconditions have been shifting the focus of public governance and socio-economic development. Morerecently, empirical studies have demonstrated a transitional epoch in which humanity is currently in: TheAnthropocene, as well as its harmful effects that degrade the biosphere, and thus our economic, political,social well-being. The casual dynamics of climate change and its impacts on life-supporting ecosystemshas increasingly been recognized by a resilient approach which incorporates adaptive processes andschemes, allowing public governance to embrace the changes rather than control uncertainty. Thisresearch introduces the interwoven concepts of adaptive capacity, adaptive governance, and resiliencewithin a social and environmental framework. It provides a review of how these concepts support aparadigm shift to mitigating current and future challenges—understood through a multidisciplinaryapproach, and how scholars have sought to develop a blueprint to improve the need to foster and mobilizeadaptive capacity within the governance of the commons. In Sweden, key governmental and businessleaders have shown the ability to foster environmental governance that is capable of developing analternative form of planning, implementing, and managing public policy. Moreover, Sweden’s concertedmultilevel governance and public policy efforts have promoted an all-encompassing generational, mainlythrough: coordinated environmental policies and private, public, and civil society partnerships. Theseinitiatives have led to innovative technologies and projects (e.g. urban vertical farming technology) as wellas cross collaboration and integration of companies and industries in order to achieve economic, social,and environmentally symbiosis.

Around the globe, towns and cities are growing rapidly in developing countries due to migration. The rate of urban growth outweighs job creation and the ability of most governments to provide basic services and infrastructure. The process of migration often precipitates into high levels of poverty and hunger, leading many urban dwellers to engage in agricultural activities to help themselves in satisfying their food need. The context of the research area is the NMBM townships where urban agriculture projects are taking place. There are three urban agriculture projects that were selected for this study and these are located in three different townships within the NMBM. Two of these projects are located in the Port Elizabeth area, which are the Emmanuel Haven Hydroponics Project, which is located in Motherwell Township, and the Walmer Hydroponics Co-operative that is in Walmer Township. The third project is located in the Uitenhage area near Kwa Nobuhle Township and that is the Tinarha Agriculture Tourism Initiative (TATI). The discussion in this research focuses on the NMBM poverty alleviation projects in the form of urban agriculture as a key driver of LED. The discussion also focuses on different factors that are required for urban agriculture projects to be effective and sustainable in the NMBM. Five project participants from each project responded to a structured questionnaire. Two municipal officials, the Agricultural Technician and the Urban Agriculture Director were interviewed and responded to a separate structured questionnaire. The third official, Assistant Director for Economic Development and Recreational Services was not interviewed but completed a questionnaire. The aim of the interviews was to determine the following from the project participants: (i) The impact of the projects in their livelihood; (ii) The role of the projects in creating employment; (iii) The views of the project participants regarding the sustainability of the projects. vi The aim of the interviews was to determine the following from the municipal managers: (i) The approach of the NMBM to urban agriculture initiatives as a LED strategy; (ii) The role of NMBM to ensure sustainability of the urban agriculture projects. The theoretical base that underpins this research hinges on four theoretical approaches: the basic needs approach, the people-centred development approach, the participation approach and the sustainable development approach. The research method that was chosen for this study is qualitative method included the following data collection instruments a literature review, a documentary analysis, a survey using questionnaires and interviews with project participants and municipal officials responsible for urban agriculture in the NMBM. The literature review formed the conceptual basis against which the information gained from documentary analysis, interviews and questionnaires were analysed. The projects that participated in the study were formed, amongst others, to alleviate poverty, thereby serving one of the basic needs which is food. Food is one of the basic needs in terms of Maslow‟s Hierarchy of Needs. The data collected in this study revealed that the three projects helped the project participants a great deal in meeting their basic needs, especially the food need. Therefore, there is a direct connection between the Basic Needs theory and the rationale behind the formation of these projects. In conclusion, the researcher has been able to draw a link between the theoretical underpinnings of the study and the practice as represented by experiences of the group sample. The researcher has also been able to demonstrate how the aims and the objectives of the study have been met.

Des particules ultrafines y compris nanométriques, enrichies en métaux (PM) sont émises dans l'atmosphère en zones industrielles et urbaines, puis sont transférées vers les écosystèmes terrestres et aquatiques, avec des conséquences sur la qualité des plantes et la santé humaine. Dans un contexte socio-scientifique mondial où la réglementation sur l’impact (éco)toxicologique des substances et les pressions de l'espace public se renforcent, des études d'impacts environnement-santé sur tout le cycle de vie des PM sont indispensables. La thèse visait tout d'abord l’étude du devenir et de l’impact des métaux des PM: leur cinétique de transfert, les mécanismes de phytodisponibilité, phytotoxicité, et les risques pour la santé humaine lors de l’ingestion de végétaux pollués. Ensuite, à travers le cas de potagers urbains en Chine, une étude socio-scientifique a été réalisée afin de proposer des moyens de gestion durable des risques environnement-santé. Les légumes peuvent accumuler des quantités importantes de métaux par absorption foliaire lorsque des PM pénètrent par les stomates. Des PM de PbO et des nano-CuO induisent une forte phytotoxicité (réduction de la biomasse et des échanges gazeux, nécroses). La phytotoxicité n’est pas simplement régie par la concentration totale en métaux car des bio-transformations se produisent et modifient les formes chimiques des métaux. L’analyse par résonance paramagnétique électronique (EPR) a mis en évidence un changement de spéciation du cuivre dans les tissus des feuilles. Par ailleurs, une influence significative de la nature du métal, de l’espèce végétale et du type d’exposition (foliaire/racinaire) sur la bioaccessibilité gastro-intestinale des éléments a été démontrée. A proximité d’un incinérateur de déchets ou d’une autoroute, l’absorption foliaire des PM induit des concentrations élevée en métaux dans les plantes, en plus du transfert sol-plante. Une bioaccessibilité humaine relativement élevée (60-79%) a été mesurée, suggérant un risque potentiel pour la santé en cas de consommation régulière. Les jardins potagers étudiés présentent un risque sanitaire faible (cas de l’incinérateur) ou modéré (cas de l’autoroute) à l'égard de la consommation humaine des légumes étudiés. Mais, une exposition à différents polluants organiques en plus des métaux est souvent possible. Cette thèse souligne l'importance de prendre en compte l'influence de l'atmosphère en plus de la qualité du sol pour estimer la qualité des plantes consommées cultivées en zones anthropisées (fermes et jardins urbains), pour la gestion durable des agricultures urbaines / Ultrafine particles including nanosized enriched with metal(loid)s (PM) are emitted into the atmosphere of industrial or urban areas, these PM can transfer into soil and water ecosystems and have consequences on plant quality and human health. In a global socio-scientific context that regulation on (eco)toxicity of chemicals and public space pressures are recently increased, studies of environmental and health impacts throughout the life cycle of PM are of crucial sanitary concern. The PhD aims first to study metal(loid)s present in the PM: their transfer kinetic and mechanism of phytoavailability, phytotoxicity, and human health risks-ingestion bioaccessibility. Then, through the case of vegetable gardens near an incinerator and a highway in China, a socio-scientific study was performed in order to give suggestions for sustainable environmental and health risk management for these sites. Vegetables can significantly accumulate metal(loid)s by foliar uptake when PM directly enter into leaves through stomata apertures. Ultrafine PbO and nano-CuO particles caused serious phytotoxicity (reduced biomass and gaseous exchange, and necrosis) after interaction with leaf surface. Phytotoxicity of metal(loid)s is not simply governed by their total concentration, but also depended on the potential bio-transformation. Electron paramagnetic resonance (EPR) analysis clearly evidenced copper speciation change in leaf tissues. Moreover, a significant influence of the nature of metal, plant species and the exposure pathways (foliar/root) on gastro-bioaccessibility of metal(loid)s had been demonstrated. For a social-scientific study near waste incinerator and roadside, we found that atmosphere PM fallouts can induce significant metal foliar uptake in addition to soil-plant transfer. The relatively high human bioaccessibility of metal (60-79%) was measured, suggesting a potential health risk in the case of regular consumption of polluted vegetables. Vegetable gardens present a low (waste incinerator) or moderate (highway) health risk with respect to human consumption quantity of the investigated vegetables, but exposure to different organic pollutants in addition to metals is often possible. Our studies highlight the importance of taking atmosphere and soil quality into account for estimating the quality of consumed plants grown in anthropic areas (farms and kitchen gardens), and for sustainable management of urban agricultures.