1,007 research outputs found

    Urban Climate Design:

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    This thesis presents research into the possibilities for climate adaptation in Dutch urban areas. We want to know how cities can best prepare for extreme rainfall, droughts, and heat waves in future climates. These events are likely to become more frequent and more extreme. The focus is on heat resistance as this has been a neglected concept in Dutch urban planning. The aim of this study is to extend our knowledge of the effects of climate-adaptation measures and to stimulate the implementation of such measures in the design of public space. Anticipating on the effects of climate change, the research was guided by the question: Which urban design principles can be applied in specific Dutch neighbourhoods to respond to the effects of climate change, especially in terms of outdoor thermal comfort and water management? The three stages of the project are:  A literature review of existing knowledge on climate adaptation and knowledge gaps Research into the specific field of urban climatology Applied research on the broader field of urban planning The urban climate and adaptation measures In the evaluation of measures for climate robust urban areas it is important to gauge the extent of the effects of such measures. These effects are generally expressed in terms of air temperature. However, the comparison of results of measures from various studies is not a simple matter: there are significant differences in spatial, climatological and methodological variations adopted in these studies. Bringing results together from very specific studies may give an impression of the potential of certain measures. For example, most studies support the idea that greening has the highest effect on thermal comfort as it provides both shade and active cooling due to ‘evapotranspiration’1. Nevertheless, vegetation can also retain heat, as we can feel after sundown. Other measures that were investigated for their effects are water, urban morphology, materials and colour. Simulations and measurements Contextual aspects and combinations of measures can seriously influence the effects of measures. To get a grip on such effects and their co-occurrence (interrelations), possible adaptations to an existing rural configuration were modelled and their effects on the microclimate were simulated using the numerical program ENVI-met. It is demonstrated that, for instance, trees combined with highly reflective façades do often not provide cooling, whereas trees combined with moderate façade colouring does. To assess the effects of a single measure, independent of its context, single parameter simulations of thermal comfort (PET) were performed. This is the first time that such a comparative study was undertaken in The Netherlands. The complexity of the situations was increased gradually from an empty field with only pavement or only grass, to pavement with grass and a single building, moving up to a building with a few trees to many trees, multiple buildings and built forms.  During this study it became clear that airflow has a significant influence on the comfort temperature. However, cooling by means of creating drafts on a mesoscale is difficult to manage and control. The low wind speed, which is typical for Dutch heat waves, provides ventilation through thermal stratification. Airflow between warm and cool spaces only occurs with sufficient temperature differences and low wind speed. This principle was investigated on the side towards new measures because little is known about the effects of generating airflow as a result of façade colour. Measurements were performed first in a small-scale experiment in a controlled area and when results seemed promising this was extended to a full-scale situation on an average Summer’s day.  Research design In current practice, urban design pays little or no attention to the urban microclimate and urban-heat stress. Designers indicate that they have insufficient knowledge and evaluation instruments. The design study discussed in the third part of this thesis provides examples of climate adaptive applications and suggestions for design strategies. Using urban typologies makes it possible to integrate the microclimate in the design without needing urban microclimate expertise. By analysing specific neighbourhood typologies applying a variety of microclimate indicators three simple distinctive parameters emerge:  balance between pavement and natural surfaces; building height; built form. Design solutions were applied to reveal spatial implications for most of the neighbourhoods in the analysis and serve as examples and a source of inspiration. Promising and neighbourhood-specific measures were selected per neighbourhood type to support the design process. To demonstrate how microclimates can be managed with design choices, a design case was developed in more detail for three cities. Prioritizing measures at the design stage depends on many external and intrinsic factors. The three designs in this thesis follow the same path: analysis > maximisation > optimisation > integration. When maximization focuses on thermal comfort only design measures concerning this aspect are applied. Prioritization can be applied in a three-step strategy of: warming prevention, passive cooling and active cooling. The design process is an iterative process in which promising combinations may be found in the optimization and this may require additional analysis. This thesis hopes to build bridges between knowledge and science and the practice of the design of public space. That goal is approached with a product that unfolds from the three parts of the study:  Factsheets to simply check and evaluate mechanisms and affordances of measures; Guidelines for the further development of knowledge of and design with urban microclimates; A categorized set of measures to be able to select the right measure for the right neighbourhood typology. The study is part of a consortium of complementary research projects and stakeholders with the aim to generate knowledge through research as input for councils and other stakeholders. In addition, three participating municipal councils have gained further insight into cases that were proposed by them. &nbsp

    Urban and regional heat island adaptation measures in the Netherlands

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    The urban planner´s role should be adapted to the current globalised and overspecialised economic and environmental context, envisioning a balance at the regional scale, apprehending not only new technologies, but also new mapping principles, that allow obtaining multidisciplinary integral overviews since the preliminary stages of the design process. The urban heat Island (UHI) is one of the main phenomena affecting the urban climate. In the Netherlands, during the heat wave of 2006, more than 1,000 extra deaths were registered. UHI-related parameters are an example of new elements that should be taken into consideration since the early phases of the design process. PROBLEM STATEMENT Thus, the development of urban design guidelines to reduce the heat islands in Dutch cities and regions requires first an overall reflection on the heat island phenomenom (relevance of the large scale assessment, existing tools, instruments) and proposal of integrative and catalysing mapping strategies and then a specific assessment of the phenomenom at the selected locations in The Netherlands (testing those principles). MAIN RESEARCH QUESTION Could the use of satellite imagery help analyse the UHI in the Netherlands and contribute to suggest catalysing mitigation acions actions implementable in the existing urban context of the cities, regions and provinces assessed? METHOD The development of urban design principles that aim at reaching a physical balance at the regional scale is critical to ensure a reduction of the UHI effect. Landsat and Modis satellite imagery can be analysed and processed using ATCOR 2/3, ENVI 4.7 and GIS, allowing not only a neighbourhood, city and regional scale assessment, but also generating holistic catalysing mapping typologies: game-board, rhizome, layering and drift, which are critical to ensure the integration of all parameters. The scientific inputs need to be combined not only with other disciplines but often also with existing urban plans. The connection between scientific research and existing agreed visions is critical to ensure the integration of new aspects into the plans. RESULTS At the neighbourhood level the areas that have a greater heat concentration in the cities of Delft, Leiden, Gouda, Utrecht and Den Bosch are the city centres characterised by their red ceramic roof tiles, brick street paving, and canals. Several mitigation strategies could be implemented to improve the UHI effect in those areas; however, since the city centres are consolidated and listed urban areas, the mitigation measures that would be easier to implement would consist in improving the roof albedo. A consistent implementation of albedo improvement measures (improving the thermal behaviour not only of flat roofs, but also of tiled pitched roofs) of all roofs included in the identified hotspots (with an average storage heat flux greater than 90 W/m2) would help reduce the temperatures between 1.4°C and 3°C. Pre-war and post-war compact and ground-based neighbourhoods present similar thermal behaviour of the surface cover, and green neighbourhoods and small urban centres also present similar thermal behaviour. At the city scale the analysis of 21 medium-size cities in the province of North Brabant, which belongs to the South region of the county -in relative terms the most affected by the UHI phenomenon during the heat wave of 2006-, reveals that albedo and normalised difference vegetation index (NDVI) are the most relevant parameters influencing the average nightime land surface temperature (LST). Thus, imperviousness, distance to the nearest town and the area of the cities do not seem to play a significant role in the LST night values for the medium-size cities analysed in the region of North Brabant, which do not exceed 7,700 ha in any case. The future growth of most medium-size cities of the regions will not per se aggravate the UHI phenomenon; in turn it will be the design of the new neighbourhoods that will impact the formation of urban heat in the province. The average day LST of provincial parks in South Holland varies depending on the land use. The analysis of the average night LST varies depending of the land use of the patches. The following surfaces are arranged from the lowest to the highest temperatures: water surfaces, forests, cropland, and greenhouse areas. For each of these land uses, NDVI, imperviousness and landscape shape index (LSI) shape index influence the thermal behaviour of the patches differently. NDVI is inversely correlated to day LST for all categories, imperviousness is correlated to day LST for all areas which do not comprise a significant presence of greenhouses (grassland and built patches) and inversely correlated to LST for areas with a high presence of greenhouses (cropland and warehouses). Greenhouse surfaces have highly reflective roofs, which contribute to the reduction of day LST. Finally, landscape shape index varies depending on the nature of the surrounding patches, especially for small patches (built areas, forests and greenhouse areas). When the patches analysed are surrounded by warmer land uses, slender and scattered patches are warmer, more compact and large ones are cooler. In turn, when they are surrounded by cooler patches it is the opposite: slenderer and scattered patches are cooler and more compact and larger ones are warmer. In Midden-Delfland (1 of the 6 South Holland provincial parks), most of the hotspots surrounding the park are adjacent to grassland patches. The measure to increase the cooling capacity of those patches would consist in a change of land use and/or an increase of NDVI of the existing grassland patches. CONCLUSIONS Satellite imagery can be used not only to analyse the heat island phenomenom in Dutch neighbourhoods, cities and regions (identify neighbourhoods with highest surface temperature, identify impact of city size and morphology in surface temperature, calcuate average surface temperature for different land uses…), but also to suggest mitigation actions for the areas assessed. Moreover, satellite imagery is here used to generate catalysing mapping typologies: game-board, rhizome, layering and drift, ensuring that the measures proposed remain accurate enough to actualy be efficient and open enough to be compatible with the rest of urban planning priorities

    Urban and regional heat island adaptation measures in the Netherlands

    Get PDF
    The urban planner´s role should be adapted to the current globalised and overspecialised economic and environmental context, envisioning a balance at the regional scale, apprehending not only new technologies, but also new mapping principles, that allow obtaining multidisciplinary integral overviews since the preliminary stages of the design process. The urban heat Island (UHI) is one of the main phenomena affecting the urban climate. In the Netherlands, during the heat wave of 2006, more than 1,000 extra deaths were registered. UHI-related parameters are an example of new elements that should be taken into consideration since the early phases of the design process. Problem statement Thus, the development of urban design guidelines to reduce the heat islands in Dutch cities and regions requires first an overall reflection on the heat island phenomenom (relevance of the large scale assessment, existing tools, instruments) and proposal of integrative and catalysing mapping strategies and then a specific assessment of the phenomenom at the selected locations in The Netherlands (testing those principles). Main research question Could the use of satellite imagery help analyse the UHI in the Netherlands and contribute to suggest catalysing mitigation acions actions implementable in the existing urban context of the cities, regions and provinces assessed? Method The development of urban design principles that aim at reaching a physical balance at the regional scale is critical to ensure a reduction of the UHI effect. Landsat and Modis satellite imagery can be analysed and processed using ATCOR 2/3, ENVI 4.7 and GIS, allowing not only a neighbourhood, city and regional scale assessment, but also generating holistic catalysing mapping typologies: game-board, rhizome, layering and drift, which are critical to ensure the integration of all parameters. The scientific inputs need to be combined not only with other disciplines but often also with existing urban plans. The connection between scientific research and existing agreed visions is critical to ensure the integration of new aspects into the plans. Results At the neighbourhood level the areas that have a greater heat concentration in the cities of Delft, Leiden, Gouda, Utrecht and Den Bosch are the city centres characterised by their red ceramic roof tiles, brick street paving, and canals. Several mitigation strategies could be implemented to improve the UHI effect in those areas; however, since the city centres are consolidated and listed urban areas, the mitigation measures that would be easier to implement would consist in improving the roof albedo. A consistent implementation of albedo improvement measures (improving the thermal behaviour not only of flat roofs, but also of tiled pitched roofs) of all roofs included in the identified hotspots (with an average storage heat flux greater than 90 W/m2) would help reduce the temperatures between 1.4°C and 3°C. Pre-war and post-war compact and ground-based neighbourhoods present similar thermal behaviour of the surface cover, and green neighbourhoods and small urban centres also present similar thermal behaviour. At the city scale the analysis of 21 medium-size cities in the province of North Brabant, which belongs to the South region of the county -in relative terms the most affected by the UHI phenomenon during the heat wave of 2006-, reveals that albedo and normalised difference vegetation index (NDVI) are the most relevant parameters influencing the average nightime land surface temperature (LST). Thus, imperviousness, distance to the nearest town and the area of the cities do not seem to play a significant role in the LST night values for the medium-size cities analysed in the region of North Brabant, which do not exceed 7,700 ha in any case. The future growth of most medium-size cities of the regions will not per se aggravate the UHI phenomenon; in turn it will be the design of the new neighbourhoods that will impact the formation of urban heat in the province. The average day LST of provincial parks in South Holland varies depending on the land use. The analysis of the average night LST varies depending of the land use of the patches. The following surfaces are arranged from the lowest to the highest temperatures: water surfaces, forests, cropland, and greenhouse areas. For each of these land uses, NDVI, imperviousness and landscape shape index (LSI) shape index influence the thermal behaviour of the patches differently. NDVI is inversely correlated to day LST for all categories, imperviousness is correlated to day LST for all areas which do not comprise a significant presence of greenhouses (grassland and built patches) and inversely correlated to LST for areas with a high presence of greenhouses (cropland and warehouses). Greenhouse surfaces have highly reflective roofs, which contribute to the reduction of day LST. Finally, landscape shape index varies depending on the nature of the surrounding patches, especially for small patches (built areas, forests and greenhouse areas). When the patches analysed are surrounded by warmer land uses, slender and scattered patches are warmer, more compact and large ones are cooler. In turn, when they are surrounded by cooler patches it is the opposite: slenderer and scattered patches are cooler and more compact and larger ones are warmer. In Midden-Delfland (1 of the 6 South Holland provincial parks), most of the hotspots surrounding the park are adjacent to grassland patches. The measure to increase the cooling capacity of those patches would consist in a change of land use and/or an increase of NDVI of the existing grassland patches. Conclusions Satellite imagery can be used not only to analyse the heat island phenomenom in Dutch neighbourhoods, cities and regions (identify neighbourhoods with highest surface temperature, identify impact of city size and morphology in surface temperature, calcuate average surface temperature for different land uses…), but also to suggest mitigation actions for the areas assessed. Moreover, satellite imagery is here used to generate catalysing mapping typologies: game-board, rhizome, layering and drift, ensuring that the measures proposed remain accurate enough to actualy be efficient and open enough to be compatible with the rest of urban planning priorities

    Technology-Driven Transition in Urban Food Production Practices : A Case Study of Shanghai

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    The continuing decline of arable land per person and global human population growth are raising concerns about food security. Recent advances in horticultural technology (i.e., growing using light-emitting diode (LED) lighting, hydroponics, vertical farming, and controlled environments) have changed the ways in which vegetables can be produced and supplied. The emerging technology makes it possible to produce more food using fewer resources, independent of the weather and the need for land. They allow bringing agricultural practices inside urban built up spaces and making horticultural production an integrated part of the daily life of urban residents. However, the process and consequences of this technology-driven transition on urban planning and development are hardly understood. This paper uses the theory of multi-level perspective (MLP) on sustainability transitions and actor\u2013network theory (ANT) to explore this technology-driven transition and its adoption in urban planning and development. The high-tech horticulture zone development in Shanghai was used as a case study. The results show the importance of both social (i.e., policymakers and planners) and material (i.e., technologies and policy documents) actants in the transition of the sociotechnical regime. Furthermore, the transition toward sustainable urban horticulture practices requires the simultaneous preparation of supportive and compatible spatial development, agricultural and sustainable development policies, and adequate policy implementation and evaluation tools to increase the competitive strength of innovative practices

    The Socio-spatial transition of Beijing, in between communal space and associative space

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    Abstract In this research, based on socio-spatiality as the starting point, it has conducted extensive city space analysis to advance a new urban social space theory. Resting upon the basis of traditional continent philosophy, this social space theory has adopted the structuration methods, at the same time trying to build certain combination between theoretical frame work establishment and empirical observations. Therefore, the socio-spatial transition study is neither a macro theory of traditional structuralism nor a typology of urban planning theory, or a positivism social geography, but an operative theory on practical purpose. Firstly, what’s distinct from the traditional structuralism is that this study examines the endless transiting structural relations, not macroscopic narrations of absolute definition and structure. In fact, any city and space are always co-existed in their structurational transiting relationship, thus research in transition has become the main body of this study. And case study is a must for research in transition, as part of efforts to apply the structuration concept into practice reason. Secondly, this study first establishes the fundamental structuration concept of socio-spatial transition, which, as an operative tool, is applied to conduct transition analysis on specific case about the City of Beijing. Therefore, as a social space theory, referring to as science, remains criticism of traditional continent philosophy. However, this criticism did not working on the level of ideology or conceptions, but on transiting under structural relations, keeping it from incompetent ideology criticism of continental critical theory. Unfortunately contemporary urban and space development have now gone extremely unbalanced under a background of globalization; yet traditional macro theories are incapable of either producing significant impact on practice or helping people identify practical problems. While facing general issues, particularly the Chinese urban issue category established on a meta-structured city mode, the micro-case study has plunged into dilemma for unknowing either to ask questions or to answer questions. Therefore, this study is set to identify dilemma and find direction for future relevant research. In this dissertation, Beijing is used as a model, and structuration methods as tools. It has extensively analyzed the social-spatial transition of the city space of Beijing, acquiring brand-new knowledge of its urban space development. It is helpful to an in-depth understanding of the city space development not only in Beijing, but also in many other cities that were influenced by the capital model of Beijing. Since the start of reform and opening-up, China has created a unique development mode of the new-styled metropolitan and urbanization in history. This research is expected to analyze or decode what China’s urban development in between communal space and associative space

    The Socio-spatial transition of Beijing, in between communal space and associative space

    Get PDF
    Abstract In this research, based on socio-spatiality as the starting point, it has conducted extensive city space analysis to advance a new urban social space theory. Resting upon the basis of traditional continent philosophy, this social space theory has adopted the structuration methods, at the same time trying to build certain combination between theoretical frame work establishment and empirical observations. Therefore, the socio-spatial transition study is neither a macro theory of traditional structuralism nor a typology of urban planning theory, or a positivism social geography, but an operative theory on practical purpose. Firstly, what’s distinct from the traditional structuralism is that this study examines the endless transiting structural relations, not macroscopic narrations of absolute definition and structure. In fact, any city and space are always co-existed in their structurational transiting relationship, thus research in transition has become the main body of this study. And case study is a must for research in transition, as part of efforts to apply the structuration concept into practice reason. Secondly, this study first establishes the fundamental structuration concept of socio-spatial transition, which, as an operative tool, is applied to conduct transition analysis on specific case about the City of Beijing. Therefore, as a social space theory, referring to as science, remains criticism of traditional continent philosophy. However, this criticism did not working on the level of ideology or conceptions, but on transiting under structural relations, keeping it from incompetent ideology criticism of continental critical theory. Unfortunately contemporary urban and space development have now gone extremely unbalanced under a background of globalization; yet traditional macro theories are incapable of either producing significant impact on practice or helping people identify practical problems. While facing general issues, particularly the Chinese urban issue category established on a meta-structured city mode, the micro-case study has plunged into dilemma for unknowing either to ask questions or to answer questions. Therefore, this study is set to identify dilemma and find direction for future relevant research. In this dissertation, Beijing is used as a model, and structuration methods as tools. It has extensively analyzed the social-spatial transition of the city space of Beijing, acquiring brand-new knowledge of its urban space development. It is helpful to an in-depth understanding of the city space development not only in Beijing, but also in many other cities that were influenced by the capital model of Beijing. Since the start of reform and opening-up, China has created a unique development mode of the new-styled metropolitan and urbanization in history. This research is expected to analyze or decode what China’s urban development in between communal space and associative space
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