Thesis (MPhil)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The particular global context that is fundamentally altering the world is one in which the combined resource requirements of cities are unprecedented. This thesis communicates the thoughts, ideas and research observations on contemporary urbanisation dynamics through a synthesis of various perspectives. This conceptual fusion, as an attempt to provide a holistic overview of contemporary urban dynamics, forms the basis for developing a framework from which the multiple dimensions of cities can be addressed. This theoretical framework, which includes empirical analyses on the state of cities, is then applied to Johannesburg as a case study for deepening the understanding of urban dynamics and to assess implementation of the theoretical framework in reality. Despite being guided by the general aims of investigating current urban growth trends and the conceptual frameworks with which urban systems could be better understood, the complexity of the task at hand defied a static and linear research process. The ideas that emerged through the research journey, as opposed to a process, were synthesised using a literature review from which the framework of managing complex social-ecological systems was developed. Central to this framework is the metaphor of resilience, which through the idea of systemic adaptability, prioritises the need for both social and ecological opportunity to be enhanced. This is critical in the face of cross-cutting global challenges and in terms of cities as archetypical complex social-ecological systems. In reviewing literature on contemporary urbanisation dynamics, it was found that the socio-economic, spatial and ecological tensions characterising developing country cities, require strategies to enhance urban resilience rooted in local social and ecological capabilities that differ from developed nations’ contexts. These practical concerns were the catalyst for suggesting green infrastructure as a framework in which the joint social and ecological values of green assets are valued equally. This in line with the logic of enhancing a system’s overall systemic adaptability. The theoretical frameworks included in the literature review, therefore, emerged through the weaving back and forth of thoughts, debates and practical concerns about creating resilience between people and nature in the urban landscapes of developing countries The methodological implications of a green infrastructure framework resulted in the need to determine the total economic value of ecosystem services, as the benefits that society accrues through ecosystem functioning. Valuing both the social and ecological benefits of such ecosystem derivatives, not only relates to the concept of mutual resilience building, but makes the economic case for investment in natural assets. Through experience with this methodology, it emerged that valuation exercises of ecosystem services require primary research that connects physical data on ecosystem functioning to tangible economic values. In the chosen case study, however, this original research is yet to take place and methodologies for valuing Johannesburg’s green assets had to unfold based on data availability. The development of a methodology within a methodology is a major feature of this paper, which is guided by the logic that for overall systemic resilience to be sustained, investment in natural assets needs to explicitly account for the total economic values of ecosystem services. The conclusions suggest that Johannesburg is nevertheless in a unique position to capitalise on the concept of green infrastructure, from which social and ecological opportunity can be mutually enhanced. In a paradoxical way, the city’s tree-planting boom that resulted in the construction of the world’s largest urban forest in natural savannah grassland, has created inventories of ecological and social resilience that represent the multifunctional value of green assets, if valued explicitly. Recognition of these values shows that ecological assets extend beyond publicly delineated open space and that Johannesburg’s culture of greening is potentially playing a significant role in sustaining the resilience between its people and nature. However, until the detailed base research is conducted on the connections between Johannesburg’s green assets and their associated social and ecological dividends, these assets remain potential inventories of resilience whose values are yet to be fully determined. The recommendations of this thesis are therefore largely to strengthen the research and data bases on Johannesburg’s green assets. Original research is needed so that precise valuation exercises of Johannesburg’s ecosystem services can take place. This research is also the foundation from which a more robust and empirically sound case can be made for motivating investment in Johannesburg’s strategically unique green infrastructure, in the context of social-ecological challenges and the global movement towards green economies, jobs and cities. / AFRIKAANSE OPSOMMING: Die spesifieke globale konteks wat die wêreld ten diepste verander, is ’n konteks waarin die gekombineerde behoeftes van stede ongekend is. Deur ’n samevatting van verskeie perspektiewe bied hierdie tesis gedagtes, idees en navorsingswaarnemings oor die hedendaagse stadsdinamika. Hierdie samevoeging van konsepte, as ’n poging om ’n holistiese oorsig van hedendaagse stadsdinamika te bied, vorm die grondslag vir die ontwikkeling van ’n raamwerk van waaruit die veelvuldige dimensies van stede benader kan word. Hierdie teoretiese raamwerk, wat empiriese analises van die stand van stede insluit, word dan toegepas op Johannesburg as ’n gevallestudie om die stadsdinamika beter te verstaan en die gebruik van die teoretiese raamwerk in die praktyk te evalueer. Die gedagtes wat uit die navorsing voortgespruit het, word saamgevat deur ’n oorsig te gee van literatuur waaruit die raamwerk vir die bestuur van komplekse sosio-ekologiese sisteme ontwikkel is. Die kern van hierdie raamwerk is die metafoor van weerstandsvermoë (“resilience”) wat, deur die gebruik van die konsep sistemiese aanpasbaarheid, die behoefte aan sowel meer sosiale as ekologiese geleenthede as die belangrikste prioriteite identifiseer. Dit is deurslaggewend in die lig van deursnee- globale uitdagings en in terme van stede as argetipiese komplekse sosio-ekologiese sisteme. In die oorsig van literatuur oor die hedendaagse stadsdinamika is daar gevind dat die sosio-ekonomiese, ruimtelike en ekologiese spanning wat stede in ontwikkelende lande kenmerk, strategieë vereis wat stadsweerstand, wat uit plaaslike sosiale en ekologiese vermoëns spruit, sal verhoog. Hierdie praktiese kwessies was die katalisator om ’n groen infrastruktuur voor te stel as die raamwerk waarbinne die gesamentlike sosiale en ekologiese waardes van groen bates ewe veel waarde dra, wat in pas is met die logiese gedagte om ’n sisteem se algehele sistemiese aanpasbaarheid te verhoog. Die teoretiese raamwerk wat ingesluit is in die literatuur wat bestudeer is, het dus na vore gekom deur die uitruil van gedagtes, debatte en praktiese benaderings tot hoe weerstandigheid geskep kan word tussen mens en natuur in die stedelike landskappe van ontwikkelende lande. Die metodologiese implikasies van ’n groen infrastruktuur-raamwerk het dit noodsaaklik gemaak om die totale ekonomiese waarde van ekosisteemdienste, as die voordele wat die samelewing deur ekosisteme ontvang, te bepaal. Die belangrikste navorsing om letterlike inligting oor Johannesburg se ekosisteemdienste aan tasbare ekonomiese waardes te verbind, moet egter nog gedoen word, en metodologieë om die stad se groen bates te evalueer moet ontwikkel word afhangende van die beskikbaarheid van inligting. Die ontwikkeling van ’n metodologie binne ’n metodologie is ’n belangrike kenmerk van hierdie tesis, wat gelei word deur die logiese gedagte dat belegging in natuurlike bates baie duidelik die totale ekonomiese waarde van ekosisteemdienste moet bepaal as algehele sistemiese weerstandsvermoë gehandhaaf wil word. Die gevolgtrekkings dui daarop dat Johannesburg nietemin in ’n unieke posisie is om finansiële voordeel uit die konsep van ’n groen infrastruktuur te trek. Op ’n teenstrydige manier het die stad se grootskaalse poging om bome aan te plant, wat gelei het tot die wêreld se grootste stedelike woud in ’n natuurlike grasvlakte, inligting gebied oor ekologiese en sosiale weerstandigheid, en dit verteenwoordig die multifunksionele waarde van groen bates as daar uitdruklik waarde daaraan geheg word. ’n Erkenning van hierdie waarde wys dat ekologiese bates verder strek as ’n openbare afgebakende oop ruimte en dat Johannesburg se groen kultuur moontlik ’n deurslaggewende rol speel om die weerstandsvermoë tussen sy mense en die natuur volhoubaar te maak. Voordat noukeurige grondnavorsing oor die verband tussen Johannesburg se groen bates en hulle gepaardgaande sosiale en ekologiese voordele egter nie uitgevoer is nie, bly hierdie bates potensiële beskrywings van weerstandsvermoë waarvan die waarde nog nie ten volle bepaal is nie. Die aanbevelings van hierdie tesis is daarom hoofsaaklik dat navorsing voortgesit word, en dat die kennisgrondslag van Johannesburg se groen bates verbreed word sodat ’n presiese evaluering van ekosisteemdienste gedoen kan word as die grondslag van sterker en empiries gestaafde redes om in die stad se groen infrastruktuur te belê.

Thesis (MPhil)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: In the 21st century, cities play a vital role in social, economic and environmental changes. They are the largest places of human settlement and it is expected that more than 80 percent of the world’s population will live in cities by 2050 (UNEP, 2012). At the same time, as the role of cities significantly increases, it also contributes to negative outcomes on the planet. In particular, the current cities’ demand for materials and energy consumption accounts for almost 80 percent of the world’s consumption and it leads to serious environmental problems. The main problems are climate change, biodiversity loss, desertification, and ecosystem degradation. In response to these urban issues, sustainable cities have emerged as an alternative way of urban life. Since cities consume a massive amount of energy, an efficient resource management system has to be established for the sustainable urban future. In addition, finding ways to reconcile economic growth, social well-being and the sustainable use of resources is imperative in urban sustainability. Since people’s lifestyle and their material footprint are dependent on the urban design, construction and operation of urban infrastructures, ways to make an urban infrastructural system more sustainable will contribute to the transition towards sustainable cities. In this study, the thesis applies Material Flow Analysis (MFA) to one of the sustainable cities, Songdo, South Korea. Before delving into the analysis, it explores the overview of the New Songdo City (NSC) project and describes its sustainable urban infrastructures. Then it examines the material flow of inputs and outputs of the city in order to reveal their sustainability and suggests a guideline for the realisation of sustainable cities. Quantitative and qualitative methodologies are used to assess and compare the material and energy flow trends for this city. The results indicate that the general material consumption in Songdo is higher than the average in South Korea. It reflects the high-income households’ consumption patterns in Songdo. In addition, one could see that the sustainable networks have merely contributed to the overall consumption. The findings from this study can be used to formulate sustainable development policies and strategies in terms of increasing the efficiency of resource and energy use in urban areas. Furthermore, this research is expected to provide a platform for realisation of sustainable cities by highlighting the important role of urban infrastructures and their material resource flow. / AFRIKAANSE OPSOMMING: In die 21ste eeu speel stede 'n belangrike rol in die sosiale, ekonomiese en omgewingskwessies veranderinge. Stede is die grootste vorm van menslike nedersetting en daar word verwag dat meer as 80 persent van die wêreld se bevolking in stede sal woon teen 2050 (UNEP, 2012). Op dieselfde tyd, namate die rol van stede aansienlik verhoog, dra dit ook by tot negatiewe uitkomste op die planeet. Veral huidige stede se vraag na materiaal en energie reken vir byna 80 persent van die wêreld se verbruik, en dit lei tot ernstige omgewingsprobleme. Die grootste probleme is klimaatsverandering, biodiversiteit verlies, verwoestyning en die agteruitgang van ekostelsels. In reaksie op hierdie stedelike kwessies het volhoubare stede na vore gekom as 'n alternatiewe vorm van stadsbewoning. Aangesien stede 'n massiewe hoeveelheid energie gebruik, moet 'n doeltreffende hulpbronbestuur stelsel vasgestel word. Daarbenewens, is dit noodsaaklik om maniere te vind om ekonomiese groei te integreer met sosiale welsyn en die volhoubare gebruik van hulpbronne. Aangesien mense se lewenstyl en hul impak op die omgewing afhanklik is van die stedelike infrastruktuur, sal maniere om hierdie infrastruktuurstelsel meer volhoubaar te maak bydra tot die oorgang na volhoubare stede. In hierde studie word, stedelike materiaalvloeiontleding toegepas op een van die volhoubare stede, Songdo, Suid-Korea. Voor die analise, sal 'n oorsig van die nuwe Songdo stad projek en die stad se volhoubare infrastruktuur gegee word. Dan word die vloei van materiaal in-en uitgange van die stad ondersoek om hul volhoubaarheid te illustreer, en stel dit 'n riglyn voor vir die verwesenliking van volhoubare stede. Kwantitatiewe en kwalitatiewe metodologie word gebruik om die materiaal en energie vloei tendense vir hierdie stad te bepaal en vergelyk. Die resultate dui daarop dat die algemene materiaal verbruik in Songdo hoër is as die gemiddelde in Korea. Dit weerspieël die hoë-inkomste huishoudings se verbruikspatrone in Songdo. Daarbenewens kan 'n mens sien dat die volhoubare netwerke slegs bygedra het tot die algehele verbruik. Die bevindinge van hierdie studie kan gebruik word om die volhoubare ontwikkeling van beleid en strategieë te formuleer in terme van die verhoging van die doeltreffendheid van die hulpbron-en energie gebruik in stedelike gebiede. Verder word verwag dat hierdie navorsing 'n platvorm in terme van die realisering van volhoubare stede sal voorsien deur die belangrike rol van stedelike infrastruktuur, en die materiaal hulpbron vloei te beklemtoon.

In the United States, the foundational myths of Nature are wilderness and pastoral arcadia. This dissertation examines a different kind of nature that emerges as habitats in urban wastelands and margins. This cosmopolitan community is a hybrid nature that is the unintended product of human activity and nature's unflagging opportunism, which I call marginal nature. Marginal nature is neither pristine nor pastoral, but rather a nature whose ecological and cultural significance requires a reassessment of our narratives of nature. The wastelands are unique sounding boards for measuring perceptions of nature, since these places provoke ambiguous responses of attraction and repulsion. I explore perceptions of wasteland habitat from the perspectives of urban space, urban ecology, and literature about urban nature. The primary methodology of this dissertation is hermeneutical inquiry which reveals the layers of environmental discourse concealing marginal nature beneath language that asks it to be something that it is not. This environmental hermeneutics focuses on key issues of the geography of nature: nonhuman agency, place, and nature/society hybrids. I argue that comprehending the lifeworld of the wastelands requires a reassessment of the concept of place as a coproduction of humans and nonhumans, that is, an ecology of place. / text

The importance of public place in the United States of America as an environment for communication, the transmission of cultural values and for the enhancement of society and community, using a comprehensive notion of entertainment as a catalyst.creative projectThis project intends to develop a catalogue of design implications for the design of a public place that successfully serves the community enhancement and the cultural transmission. This catalogue of design implications will be the result of the extensive research on the American culture, on the elements of cultural expression with emphasis on the use of entertainment as a catalyst, on the elements of urban history and the urban environment as well as on the social and commercial success of public place.contextThe context of this research is the number of issues American urban environments are facing. Most of the problems in their combination are the source of numerous urban issues. Some of the key issues that have developed on this basis are e.g. the loss of human scale or e.g. the need for a collective vision, community and cultural identity. These issues are strongly interrelated with another.issueThese are some of the deficiencies that lead to the key issue of this project: the loss of community manifested by urban isolation and fragmentation and problems relating to the humane environments and settings. Nevertheless community and cultural enhancement can help to create a greater awareness for the prerequisites for a healthy living environment. Community and cultural enhancement help to stimulate greater self-sufficiency helping to address the previously mentioned issues at their sources. The premise is that community is an essential ingredient in cohesive urban and suburban neighborhoods and is part of the positive image of a well designed and maintained city fabric.positionThe focus of this work is the community, the public place and the cultural expression with emphasis on entertainment. In the same order they represent the issue, the place and the catalyst. This work claims that entertainment can be used to design an environment enhancing community and communication. The assumption related with entertainment is that social interaction and collective well being are essential parts of community structure and therefore activities related to entertainment help to foster a collective vision.methodThe first step to prove this position is to identify the issues concerning urban settlements in the United States of America. The urban context has to be defined. The second step is to define the cultural context and to analyze the notion of entertainment as a means of cultural expression and its potential to serve as a catalyst. The third step is to identify the elements of social and commercial success of a public environment using at least two models defining those elements. Each of the three steps concludes in a set of architectural values and design elements. The fourth step is to deduce a catalogue of design implications from the information collected. This last step proposes the practical application of this research. The anticipated results of this project should be regarded as a suggestion for the practical application of this research based on the observation of and reflections on the research results, hopefully resulting in the identification of additional questions for further research. / Department of Architecture

Les milieux aquatiques en zone urbaine sont reconnus comme des îlots de biodiversité qui offrent de nombreux services écologiques. Dans cette étude, nous avons utilisé les macroinvertébrés comme bioindicateurs de la qualité écologique des étangs, petits lacs et marais de l’Île de Montréal. Les macroinvertébrés ont été récoltés durant l’été 2011 dans la zone littorale de 20 sites variant par leur urbanisation et leurs caractéristiques limnologiques. Nous avons évalué la variation dans la richesse en taxa, les indices de diversité et plusieurs métriques basées sur la composition taxonomique ou les traits fonctionnels. Nous avons déterminé la réponse des métriques aux changements dans l’urbanisation, l’aménagement et les conditions des plans d’eau. Notre étude montre que les étangs, marécages et petits lacs constituent des réserves importantes de biodiversité en zone urbaine. Les marécages naturels et les étangs et lacs permaments avaient une meilleure qualité écologique et supportaient des communautés de macroinvertébrés plus diverses et abondantes que les petits étangs temporaires aménagés. Le couvert de végétation aquatique, l’enrichissement en nutriments et en matière organique ainsi que la biomasse des algues expliquaient le plus de variation dans les macroinvertébrés. Les aménagements, la densité urbaine et la permanence de l’eau avaient aussi une bonne influence. Les métriques univariées avaient moins de potentiel que les métriques multivariées. Nous avons discuté les implications de notre étude pour le suivi environnemental de la biodiversité et la qualité écologique des milieux aquatiques en zone urbaine. / Aquatic ecosystems in urban landscapes are now recognized as good islets of biodiversity and valuable environments providing ecological services. However, more knowledge is needed to assess their ecological quality. Benthic macroinvertebrates are widely used as bioindicators, but rarely for urban ecosystems. In this study, we used macroinvertebrates to evaluate the ecological quality of urban ponds and lakes in the island of Montreal. We collected macroinvertebrates during summer 2011 in the littoral zone of 20 waterbodies varying in urban and limnological characteristics. We evaluated spatio-temporal variation in several diversity and biotic indices and multiple metrics based on taxonomic composition and functional traits. We investigated if macroinvertebrate metrics responded to variation in urban land-use, pond management and limnological conditions. Our study showed that small waterbodies, as ponds, lakes and marshes are important resources for sustaining aquatic biodiversity in urban landscapes. Natural wetlands and artifical permanent ponds had higher ecological quality and supported more diverse and abundant macroinvertebrates than artificial managed temporary ponds in municipal parks. Vegetation cover, nutrient and organic contents, and algal biomass were the most important factors explaining spatial variation in macroinvertebrate metrics. Pond management, urban density, and water permanence were also influencial factors. Univariate metrics had less potential than multivariable metrics to assess the responses of macroinvertebrates to environmental features. We discussed the implications of our study for management and quality assessment of urban ponds.

Derrière l’apparent consensus de l’application du registre de la durabilité à la ville, notre recherche contribue à analyser, dans une perspective critique, ce que recouvre la locution de ville durable dans le champ de l’urbanisme. Nos investigations reposent tout d’abord sur l’étude des modalités d’émergence de l’expression, conjuguée à l’examen du traitement dont la notion fait l’objet dans la littérature scientifique et professionnelle. Nourrie du rapport dressé entre méditerranéité et pensée complexe (MORIN 1999), l’approche est ensuite incarnée au sein d’une ville méditerranéenne : Marseille. Elle se fonde alors sur l’analyse des représentations que les acteurs en charge de la fabrique urbaine se font de la ville durable, éclairant ainsi ce qui fonde leurs actions dans ce domaine. L’enjeu réside enfin dans la mise en regard de l’ensemble avec les conséquences matérielles, socio-spatiales et vécues des productions effectives. Celle-ci s'opère à travers un cheminement exploratoire sensible ponctué d’observations et de récits d’habitants, au sein d’un secteur dont les principes de réalisation sont rattachés à l’idée de ville durable. Notre parcours de thèse montre ainsi comment, exogène aux sphères de l’urbanisme, la notion de ville durable ne constitue pas un cadre suffisamment émancipateur et robuste pour permettre aux acteurs du champ de parvenir à un renouvellement des savoirs ni de s’affranchir des contraintes et tendances lourdes qui pèsent sur la fabrique urbaine. Il propose, ce faisant, une démarche écologique permettant d’explorer ce/ceux sur quoi/qui pourraient reposer la ou plutôt les durabilités urbaines et comment. / Whilst there seems to be a consensus on the feasibility of applying sustainability thinking to town and city development, our research contributes to the critical understanding of the notion of a sustainable city within the field of urban planning. We will begin with a study of the modalities of the emergence of this term, combining it with an analysis of the ways in which the notion is used in professional and scientific literature. Following on from the correspondence drawn between "méditerranéité" and complex thinking (MORIN 1999), our approach will then be embodied in the heart of a Mediterranean city : Marseille. Considering the mental pictures conjured up by the notion of sustainable city, we thus analyse the ways in which the elements of meaning previously highlighted are being used or not, interpreted, or even diverted, and how they influence decisions and actions. As the object of our work is the relationship between these and their material, socio-spatial and experiential impact, we then go on to conduct a sensitive exploration using observations and stories told by local residents within a sector in which actualisation principles are relating to the idea of sustainable city. This research shows, in the end, how the notion of sustainable city, which is exogenous to the domain of urban planning, does not offer a sufficiently emancipating or robust framework to allow the development of new “knowledge and know-how” or to outweigh the constraints and forceful trends that hinder the development of the town. This leads us to propose an "ecological" approach to explore what and whose contributions urban sustainability or rather sustainabilities might be built upon.

A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Engineering and the Built Environment, University of Witwatersrand, 2016 / This thesis is concerned with the relationship between informal settlements and green infrastructure. It uses the concept of just sustainability to explore the ways green infrastructure can contribute to more just and sustainable informal settlement interventions. The study draws on a case study design, with three low-income areas in Johannesburg serving as case studies. The first, Kya Sands, is an informal settlement that has not experienced substantive intervention. The second, Ruimsig, is an informal settlement that has experienced in situ intervention through reblocking. The third, Cosmo City, is a green-field housing development where households from informal settlements were relocated. The thesis utilised qualitative methods (semistructured interviews, transect walks, focus group discussion) for data collection across the case studies. These were supplemented by a quantitative component for data collection in an individual case and in-depth interviews with purposively selected key informants. The three cases reveal how the low-income residents in these areas derive a range of ecosystem services from natural ecosystems. A range of ecosystem disservices also came to the fore. In Ruimsig settlement, reblocking involved spatial reconfiguration that created opportunities for greening. Co-producing the in situ intervention involved some processes and outcomes related to equity and inclusion but also included situations that were exclusionary. Relocation from informal settlements into a new housing environment in Cosmo City formally created spatial opportunities for greening and reduced dependency on the natural ecosystem for certain basic resources. However, the course of events leading up to relocation and postoccupancy trajectory of green spaces reveal shortfalls in relation to justice and incognisance on socio-ecological and socio-economic realities at the planning stage. Juxtaposition between the cases of Ruismig and Cosmo City shows that in situ intervention can fulfill more principles of just sustainability in comparison with relocation. This thesis argues that careful assessment of the relationship between poor households living in informal settlements and green infrastructure — their interaction with natural ecosystems should influence the approach to informal settlement interventions. The cases reveal that achieving just sustainability in relation to green infrastructure in informal settlement intervention is not straight-forward, but not impossible. Progress towards just sustainability in the form of improvement in quality of life and in the environment requires navigating (with foresight rather than hindsight) the intricacies and dynamics obtainable in contexts into which informal settlements are embedded. / MT2017

A constituição da idéia de meio ambiente urbano é aqui avaliada sob a perspectiva das concepções que, historicamente, tentam enquadrar as cidades em categorias biológicas, tais como “corpo", “organismo" e, contemporaneamente, “(ecos)sistema". Essa tendência de naturalização ou biologização das cidades é característica do pensamento social pelo menos desde o século XIX: seus antecedentes são certamente ainda mais remotos, mas as origens de seus aspectos contemporâneos mais característicos podem ser encontradas em meados do século XVIII. Este trabalho visa resgatar alguns dos aspectos mais importantes dessa história, pondo em questão a validade de tais categorias para compreensão e intervenção sobre a cidade real. Para tanto, o trabalho dedica-se a investigar os sentidos atribuídos à idéia de natureza e a conseqüente apreciação da agência humana, e da cidade em particular, feita por essas concepções. Qualifica-se o processo de naturalização como parte de um esforço mais amplo de negação ou disciplinamento do artifício (a ação humana) e do acaso (a ausência de causalidade ou finalidade) na constituição do mundo – negação esta que resultaria em um conjunto de categorias de estase para interpretação da realidade e, afinal, em apologia do status quo. Desde o sanitarismo do século XIX até a Ecologia do pós-2ª. Guerra Mundial, passando pelo caso particularmente controverso da Eugenia, as tentativas de biologização das cidades, tanto por parte das ciências biomédicas quanto do próprio Urbanismo em constituição, apontam para uma tendência de dominação pelo conhecimento técnico que permeia de forma recorrente a modernidade capitalista. Nela, tanto a “natureza" quanto os seres humanos comuns (não “escolhidos") são concebidos como recursos naturalmente passivos e sujeitados, incapazes de criar, cabendo-lhes apenas o papel de “resistir" ou “reagir", ou ainda serem “protegidos". Esse “paradigma da dominação" é que requer reconhecimento e enfrentamento, indicando a necessidade de politizar e historicizar a questão ambiental, principalmente em relação às cidades. / In this dissertation the formulation of a concept of ‘urban environment’ is based on the perspective of ideas which have historically attempted to understand cites in biological terms, such as “body", “organism" or more recently “eco-system". This tendency to ‘naturalize’ or conceive cities in biological terms has been a characteristic of social thinking especially since the 19th century. The roots of this tendency are certainly much more remote but this perspective did receive an important impulse from the mid-18th century ideas of the enlightenment. The following dissertation attempts to recuperate some of the more important aspects of this history, questioning the validity of this tendency for the comprehension of and intervention in contemporary cities. Because of this, the study is dedicated to the investigation of the various understandings attributed to the idea of nature with their peculiar appreciation of human agency and of the city. Qualifying this process of naturalization is seen as part of a wider preoccupation of negating or disciplining notions of ‘the artificial’ seen as the product of human agency, and of ‘chance’ when seen as the absence of causality or finality, in our constitution and interpretation of the world which in very many cases becomes an apology in favor of the ‘status quo’. Since the influence of ideas based on hygiene and sanitary conditions in the 19th century and the Darwinian twin conceptions of ecology and the controversial idea of eugenics (up to the mid 20th century) urban history has accepted the expanding role of biological metaphors. This has been expressive both in the biomedical sciences and also in the evolving science of urbanism. In many senses this has been part of the wider tendency towards domination by technical knowledge which is a recurrent feature of capitalist modernity. In this interpretation the dissertation attempts to show that ‘nature’, just as much as ordinary common people are conceived as resources, ‘naturally’ passive, without any capacity to create and with a mere capacity to ‘resist’, to ‘react’ or to ‘conform’ to their eventual ‘protection’. It is this academic paradigm of domination which needs to be recognized and confronted. In this sense the dissertation is an attempt to historically politicize the environmental question, especially in its urban dimension.

Green infrastructure development is desired in many municipalities because of its potential to address pressing environmental and social issues. However, despite technical optimism, institutional challenges create significant barriers to effective green infrastructure design, implementation, and maintenance. Institutional challenges stem from the disparate scales and facility types that make up the concept of green infrastructure, which span from large-scale natural areas to small engineered bioswales. Across these disparate facilities 1) different performance metrics are used, 2) different institutions have jurisdiction, and, 3) facility types are differentially classified as assets, producing epistemological and ontological variegation across the spectrum of green infrastructure that must be negotiated within and across municipal institutions. This has led to knowledge challenges that constrain and shape facility design, implementation, maintenance, and--ultimately--performance on-the-ground. Here, the eco-techno spectrum is developed to highlight the different degree to which biological entities (e.g. plants, microbes) are incorporated as infrastructural components in facilities; this inclusion presents a major knowledge challenge to green infrastructure, namely it brings biological and ecological knowledge into traditionally engineering-dominated decision-making spaces where it does not easily fit procedures for defining, measuring, or valuing existing facility component types. Therefore, municipal institutions have created and vetted new practices, protocols, and institutional structures to appropriately implement and manage green infrastructure. The institutionalization of green infrastructure is examined in this dissertation using knowledge systems analysis in two comparative case studies conducted in Portland and Baltimore. Discourse analysis provides 'thick' description of knowledge systems dynamics within and between different municipal departments in each city; a follow-up Q-method survey is used to further examine these qualitative results and explore the subjectivities that underlie the various ways of 'knowing' green infrastructure in the city.

The Earth's climate is changing and cities are facing a warmer future. As the locus of economic activity and concentrated populations on the planet, cities are both a primary driver of greenhouse gas emissions and places where the human health impacts of climate change are directly felt. Cities increase local temperatures through the conversion of natural land covers to urban uses, and exposures to elevated temperatures represent a serious and growing health threat for urban residents. This work is concerned with understanding the interactions of global trends in climate with local influences tied to urban land covers. First, it examines temperatures during an extended period of extreme heat and asks whether changes in land surface temperatures during a heat wave are consistent in space and time across all land cover types. Second, the influences of land covers on temperatures are considered for normal and extreme summer weather to find out which characteristics of the built environment most influence temperatures during periods of extreme heat. Finally, the distribution of health vulnerabilities related to extreme heat in cities are described and examined for spatial patterns. These topics are investigated using meteorology from the summer of 2006 to identify extremely hot days in the cities of Atlanta, Chicago, Philadelphia, and Phoenix and their surrounding metropolitan regions. Remotely sensed temperature data were examined with physical and social characteristics of the urban environment to answer the questions posed above. The findings confirm that urban land covers consistently exhibit higher temperatures than surrounding rural areas and are much more likely to be among the hottest in the region, during a heat wave specifically. In some cities urban thermal anomalies grew between the beginning and end of a heat wave. The importance of previously recognized built environment thermal influences (impervious cover and tree canopy) were present, and in some cases, emphasized during extreme summer weather. Extreme heat health health vulnerability related to environmental factors coincided spatially with risks related to social status. This finding suggests that populations with fewer resources for coping with extreme heat tend to reside in built environments that increase temperatures, and thus they may be experiencing increased thermal exposures. Physical interventions and policies related to the built environment can help to reduce urban temperatures, especially during periods of extremely hot weather which are predicted to become more frequent with global climate change. In portions of the city where populations with limited adaptive capacity are concentrated, modification of the urban landscape to decrease near surface longwave radiation can reduce the chances of adverse health effects related to extreme heat. The specific programs, policies, and design strategies pursued by cities and regions must be tailored with respect to scale, location, and cultural context. This work concludes with suggestions for such strategies.