As a result of widespread urban development over the past two decades, global wetlands are disappearing at an alarming rate. This thesis develops a series of strategies for protecting wetland ecosystems from the ecological consequences that cascade through an ecosystem as a result of such development. This thesis is based on the paired assumptions that ecosystems represent networks of linked processes that operate across both local and global scales, and that the ecological integrity of any ecosystem can be maintained (a) only if the physical integrity of an ecosystem’s constituent processes is maintained, and (b) only if damage occurring at one ecological scale is prevented from affecting processes occurring at another. Thus, the strategies proposed here are multi-scalar and implemented at both the scale of the site and at the broader watershed scale. The strategies developed in this thesis focus on maintaining the physical integrity of the local wetlands as a means of protecting the processes that occur within the broader wetland ecosystem. The thesis proposes that wetland sites might be best protected from the effects of urban development by implementing a series of landscape interventions that provide the ecosystem with the means to reorient itself in new ecological relationships. Instead of attempting to recreate and control a complex set of conditions by imposing a deterministic architectural solution on the site, this strategy seeds new processes and new structural relationships such that the ecosystem reorganizes itself according to its own structural logic and grows into new stable relationships according to conditions that arise out of those processes. Because this approach generates a series of self-sustaining processes, human intervention is minimized beyond the initial stages. The stategies proposed here will be explored in the context of proposals recently announced by oil companies to develop ecologically sensitive wetland sites located on the Athabasca River in north-eastern Alberta.

This thesis examines how Tibetan residents of different social backgrounds use and experience the space of the city of Lhasa. I mainly concentrate on young Tibetan rural migrants and document a number of similarities and differences between their spatial practices and those of young Tibetans from urban backgrounds. This thesis shows that my rural migrant informants generally gravitate towards the old quarter of the city, where they practise at religious sites, attend informal private schools, and reside in heavily religious and traditionalist domestic spaces. These spatial practices largely distinguish them from young Tibetans from wealthier families (particularly those of government workers) and who have previously lived in inland China: most often these youths frequent sinicised parts of the city, inhabit domestic spaces lacking religious objects, and are either less interested in or banned from engaging in religious practice. Despite these different orientations, however, the ethnography ultimately shows that a clear-cut distinction between villagers and urbanites cannot be drawn. By looking at both the city of Lhasa and nearby rural villages, the thesis shows that neither the former nor the latter are univocally traditionalist or modernising. Furthermore, informants’ practices both persist and change over time and while throughout the fieldwork some young migrant informants continued in their largely traditionalist engagements within Lhasa’s space, others changed their attitudes and started paying less attention to religion and traditionalist pursuits. To do justice to the changing orientations of my informants, I apply a dynamic theoretical model drawn from practice theory whereby practices and predispositions are shown to be resilient, but not fixed. Ultimately, this thesis proposes that, despite the presence of often-distinct orientations between villagers and urbanites in contemporary Lhasa, all young Tibetans in the city share a common socio-political terrain. In Lhasa, traditionalist predispositions persist, but social mobility, government control, and urbanisation also often lead to the development of more practical, secular, and sinicised attitudes.

No description available.

Esta tese de doutorado tem como tema o estudo do urbanismo nas caracterizações que lhe foram dadas pelo movimento moderno e sua hipótese fundamental se refere à possibilidade de considerar como aquele movimento desenvolveu, indiretamente, um rapto do direito à cidade que passa a constituir uma categoria epistemológica na análise de planos urbanos desenvolvidos sob a sua inspiração. Para tanto e como estratégia metodológica de pesquisa foram utilizados planos urbanos modernos em confronto com a cidade enquanto realidade empírica e em processo constante de mudança. Concluiu-se que um dos fatores que podem levar muitos planos urbanos modernistas a se frustrarem está na condição com que eles conseguem (ainda que muitas vezes não perceptivelmente) raptar a cidade real existente. De modo que se propõe uma empiricização do plano no tempo e no espaço do vivido; portanto no cotidiano como signo potencial para se fazer e rever o plano urbano. Daí decorrem desdobramentos que o atual desenvolvimento dos meios tecnológicos podem oferecer para o plano urbano, visto que estes meios atuam como parte daquele cotidiano. / The subject-matter of this PhD thesis is the study of urbanism according to the characterizations it was given by the modern movement and its fundamental hypothesis refers to the possibility of considering the way in which this movement developed, indirectly, an abduction of the right to the city, which comes to constitute an epistemological category in the analysis of urban plans developed under the inspiration of this movement. In order to do this and as a methodological research strategy, we used modern urban plans confronting them with the city as an empiric reality and involved in a constant process of changes. We came to the conclusion that one of the factors that can lead many modernist urban plans to frustration resides in the condition through which they manage (even if it is not very often perceived) to abduct the real existing city. Therefore we propose an empiricization of the plan in the time and in the space of lived experience, hence, in daily life as a potential sign in order to make and revise the urban plan. As a result of this there are interpreting signs which the present development of technological means can offer to the urban plan, since these means act as a part of this daily life.

This thesis takes the typical one-to-one relationship between a tower and a lobby and asks what if a three-layer base that produces a higher density and a scale exceeding the physical boundary of a single office tower replaces the lobby. Combing retail, conference facilities and recreation the base at once consolidates the programmatic needs of office workers and thickens the singular exchange of lobby-office-lobby to one of recreation-lobby-retail-office-lobby. Spanning the length of a ten-acre site in London, the base establishes a large horizontal floor plate and introduces big-box retail and an economy privileging lower prices onto a site surrounded by boutiques and mom-and-pop stores. Instead of planar adjacencies, retail and towers overlay in section. Vertical, horizontal and transverse circulations intersect, turn and unite, forming new programmatic possibilities and proliferating the cultural, economic and social life of a tower onto the city.

The absolute polarization of contextual and tabula rasa urban models has long been advanced, even blatantly promoted, within the discipline. Taken for granted as foils, the exclusive championing and application of context or tabula rasa has only served to undermine the agency of the contemporary city. Producing an ineffectual and one-dimensional duality, cities have been reduced to futilely choose between the old and the new. A city of contradictory extremes, the clash between these concepts is embodied in the urbanism of Shanghai. With the impetus of China’s “Economic Miracle,” a previously unheard of scale and speed of urbanization has been achieved throughout the country with the creation of “instant cities.” Embraced as testing grounds for contemporary urbanism, the characteristics and conditions of the instant cities have been enthusiastically and almost universally adopted, leading to a primacy of tabula rasa and vertical development. Partially transformed by this model of erasure, Shanghai’s urbanism is defined by confrontation as the urban models of the past and present collide. The duality manifest by this conflict compels an examination of the seemingly agonistic roles of context and erasure in the city. The ambition of this thesis is to eliminate such distinctions; the choice between contextual and tabula rasa approaches does not work. This false choice produces either a conservative preservationist tourist attraction or a generic and totalizing vertical city. The shallow tendencies of both approaches threaten the city as a multiple and collective space of possibility. By adopting a broader view of context and collapsing present dualities, this project seeks to create complexity and new confrontations through an urban morphology shaped by architecture. Moving beyond contextual preservation and tabula rasa, this thesis seeks to engage and create another reality using that juxtaposition to open new relationships within the city.

The Houston Constellation is a type of architectural urbanism situated at the intersection of urban revision and projections for cultures yet unknown. The intent is to provide a template for refiguring new lines of sight and interaction within the contemporary city, between contingent forces, institutions, and a public in flux. The Houston Superdistrict: a heterogeneous collection of 20th Century urban paradigms packed loosely underneath a thick canopy. Institutions in medicine, the arts, education, and recreation make it a major hub for local and global populations. The area is undergoing a transformation, yet in contrast to its ambitious visions, current plans project investment that may drop more single objects into this static field. This project proposes an alternative. A constellation of form that slides across cold boundaries and catalyzes a new spatial consciousness to produce a newly legible environment. Encouraging creativity- the very hope for the district in the first place- begins with architectural performance and contextual interaction. Techniques and tactics of planametric alignment, visual continuity, and material cohesion provide the system a relational fitness, while establishing a larger counterform against context’s existing linear boulevards, axes, and grids. Four forms (R,G,B,O) based on site-specific conditions, constitute programmatic points with distinct characters. A complementary duality, the figures in the park (O & B) engage the spatial and airy quality of the city. While the institutional figures (R & G) embed themselves within the local form of their respective campuses. Producing new linkages between fabric and institution: the Museum of Fine Arts Houston and Rice University link through a new space for the arts in the public realm. Hermann Park’s City Beautiful design is reawoken with a new spine and periphery.

SURFcity reorganizes, redistributes, and recentralizes the peripheral urban environment of diffuse and urbanized architectures into condensed architectural form. Through surface elaboration and densification techniques, it produces a new model for a contemporary city and community. Bringing together differences otherwise experienced at a regional scale to the human scale, it produces hybrid programs, new interior public space, and allows the surounding exterior area to return to nature.

In examining the Canadian residential fabric, this thesis advocates for the design of urban dwellings which respond directly to a number of contemporary urban challenges. A number of these challenges stem from the largely suburban nature of North American cities; there are major concerns about the relative isolation and automobile dependence of contemporary suburbs, their spread into conurbations, and their environmental impacts. On the other hand, there are challenges with many typical urban infill developments as well; they are often developed for a limited range of households, lack much in the way of connections to the outdoors, and, in contrast to some of the key arguments for intensification, often perform below the level of energy efficiency we might reasonably expect in a compact, contemporary, and sustainable urban form. All of these challenges are further discussed and evaluated in chapter three of the thesis. In attempting to address these challenges in a holistic manner, this thesis makes a case for conscientiously increasing the density of the many existing low-density areas within our urban fabric, in a form which incorporates varied outdoor spaces, varied uses, varied unit types and sizes, within a relatively energy efficient form and skin. Chapter four looks at design principles, strategies, and precedents, as well as schematic designs which attempt to integrate and synthesize these objectives. In order to illustrate the application of these principles and schematic designs to an existing low density urban area, chapter five proposes a more detailed design on a large site in Westboro, Ottawa, an evolving semi-suburban area whose development dates largely from early and mid 20th century.

As distance from a house to retail sites decreases the price of a house should increase, ceteris paribus, because of increased shopping convenience. On the other hand, as distance decreases price should also decrease because the house is exposed to increased spillover of disamenities noise, light, traffic, etc. from the retail use. The study uses Computer Assisted Mass Appraisal data and a parcel level Geographic Information system map from King County (Seattle) Washington. An hedonic process is used to estimate the price effects of both the expected positive and negative price effects. Travel distance is a proxy for convenience and Euclidian distance is a proxy for negative spillovers. Standard hedonic housing price variables are used for control along with distance to other classes of non-residential uses and indexes of neighborhood street layout and connectivity. In traditional gridiron neighborhood, both convenience and negative spillovers have the expected effect on housing price. The net effect is a price effect curve with a net decrease in price at very short distances between houses and retail sites. But, beyond a short distance to the extent of convenient walking distance (about mile) the net effect is positive. In a non-traditional edge city type neighborhood, there is no effect, either positive or negative. This is due to the much greater distances between residential uses and retail uses in this type neighborhood that result from zoning that segregates land uses and long travel distance resulting from curvilinear street layout.