Urban Form Research Articles

Review: The City in Time: Contemporary Art and Urban Form in Vietnam and Cambodia, by Pamela N. Corey

Review: <i>The City in Time: Contemporary Art and Urban Form in Vietnam and Cambodia</i>, by Pamela N. Corey

Defining Integration of Climate Adaptation Strategies into Slum Upgrading: A Literature Review.

Under the Sustainable Development Goals (SDGs) no.11: make cities and human settlements inclusive, safe, resilient, and sustainable; the slum is the main target for this effort. All around the world, slums are becoming the only option for low-income communities to settle within city boundaries. This paper presents a literature review aimed to provide a more detailed understanding of knowledge related to the literature on two things, namely slum upgrading and climate change adaptation of Low-Income Communities (LIC), and also on its interrelations. The literature review uses a semi-systematic methodology, using the web of science search engines combined with google scholar. We use keywords such as slum upgrading, climate adaptation, and participatory. The search engine proposed 482 papers, 75 as data and 66 public access journal articles. Out of these numbers, we narrow down the perimeters of research scope to 71 linked to SDGs. However, only 11 are relevant to urbanized areas. This finding shows that not much literature regarding these interrelations is produced. This review explains assumed interrelationships that influence each other and exist between slum upgrading on urban riversides and forms of adaptation to climate change in urban areas. The definition of slum upgrading is an integrated and comprehensive intervention aimed to improve the physical characteristics of the environment and its inhabitants quality of life, divided into in-situ and ex-situ efforts. Climate adaptation is a process rather than a program or pattern of action by the LIC in dealing with climate change impacts comprehensively and substantially within the context of social and environmental. Their interrelations of the two themes are the physical and non-physical efforts, but also on the participatory levels. Participation determines the level of climate resiliency for the LIC. Based on the descriptions of theories related to the theme of this research, there are propositions for the field study as follows. (1) slum upgrading with adaptation sensitivity to climate change will ultimately increase the resilience of low-income communities to be more prepared to face climate change. (2) The specificity of land ownership status and cultural strength can enrich locality and social closeness. (3) The level of community participation in slum upgrading affects the climate resiliency level of the LIC.

Study on the structural characteristics of China's high-speed railway network and its coordination with economic growth based on Fractal theory

As one of the modern transportation modes, the high-speed railway network system has been a robust part of the comprehensive transportation system in China. An important topic emerges the exploration and optimization of its structural organization and coordinated relationship with the regional development, including urban form, land use, and economy. Therefore, supported by the integration of geographical information system (GIS) and fractal theory, this paper aims to carry out an investigation and discussion on the structural characteristics, including intensity (density), complexity, nonstationarity, and heterogeneity of the high-speed railway network in China (HSRNC) from the perspective of the whole country and specific regions, i.e., urban agglomerations. Moreover, based on the time-series data of network mileage expansion and economic output analysis, this study aims to evaluate and characterize the coordinated relationships between network development and economic growth in the context of the nationwide area and urban agglomerations. This study aims to explore and promote the spatial structural organization and morphology of the high-speed railway network in China, thus improving the coordinated development with the regional economic growth, for giving a new perspective to the future planning and evolution of the high-speed railway network in China.

Rise of Work from Home &amp; Post-pandemic Urban Form in Global Cities

Rise of Work from Home &amp; Post-pandemic Urban Form in Global Cities

The influence of the built environment on active school travel in the Netherlands: A mode choice analysis

Studies indicate that the amount of active travel among children is decreasing worldwide. The circumstances around travel modes and routes of children and young adolescents are less known if compared to adults’ walking or cycling. There is a growing interest in mobility patterns of children to school, especially. Active School Travel (AST) is decreasing in developed nations. This study explored which structural elements in the built environment of home and school locations influence AST of Dutch students. We used multinomial logistic regressions to study the effects of built environments on walking and cycling by students in the Netherlands. Findings about the design of environments around homes and schools suggest that variations in personal characteristics, temperature, destination proximity, traffic safety conditions, and urban form can influence AST. Safety conditions seem to play a spurious role in the relationship between built environments and AST, reflecting counterintuitive results if compared to adult travel research. Findings were mixed regarding directionality and significance levels between transport modes and variables, which highlights the importance of considering target groups, modes and locations of students and schools when planning for effective interventions. The findings can be valuable for both academia and policymakers, supporting strategies that could be adopted by municipalities and encouraged by parents or schools.

Assessment of urban form resilience: a review of literature in the context of the Global South

Assessment of urban form resilience: a review of literature in the context of the Global South

An XGBoost-SHAP approach to quantifying morphological impact on urban flooding susceptibility

Urban flooding risks, often overlooked by conventional methods, can be profoundly affected by city configurations. However, explainable Artificial Intelligence could provide insights into how urban configurations affected urban flooding. This study, taking entered on Shenzhen City, deploys an XGBoost, integrating SHapley Additive exPlanation and Partial Dependency Plots, to assess how urban morphology influences urban flooding susceptibility. The models and strategies presented in this study aimed to adapt to extreme storms from the perspective of city spatial configuration planning. The findings underscore the varying impact of disaster variables on urban flooding, with morphological attributes becoming highly significant during severe inundations. In the analysis, mean building volume emerged as a pivotal parameter, with a mean SHAP value of 0.0107 m and a contribution ratio of 9.70 %. The study indicates that building configurations should be optimized to minimize urban flooding risks. It is recommended that the Mean Building Volume (MBV) be maintained within the range of 1.25 km3 to 2.5 km3, and the Standard Deviation of Building Volume (SDBV) be kept below 2.814 km3. By harnessing explainable Artificial Intelligence algorithms, this study offers insights into the intricate relationship between urban forms and flood risk, thereby informing the development of effective urban flooding adaptation strategies.

Exploring the Relationships Between Urban Form, Transportation Infrastructure, and Travel Behaviour: A Cross-City Comparison of Singapore, Beijing, Shanghai, Mumbai, Delhi, and Tokyo

This paper combines traffic statistics of six typical Asian cities, including population density, GDP per capita, mode share, etc., and provides an in-depth analysis of the cities traffic situation. We summarized relationships between income, population density, transportation infrastructure, transportation policies in each city, and the mode of transportation in each area. We find that the population density in a town dramatically impacts the public transit systems, and there are significant relationships between the local travel policies and the mode share. In addition to the conclusions, we summarized the existing problems in this paper and made suggestions for future research in the field.

Examining temporally varying nonlinear effects of urban form on urban heat island using explainable machine learning: A case of Seoul

Many empirical studies have examined the relationship between urban form and canopy layer urban heat island (CUHI). However, these studies mostly have used small sample sizes and statistical methods that assume CUHI responds linearly to urban form features. Additionally, the differences in the effect of urban form on CUHI at different time instances during the diurnal cycle have not received sufficient attention. To address these issues, this study employs a relatively large sample of 1,058 microclimate sensors in Seoul, Korea, and analyzes CUHI at 9 a.m., 3 p.m., and 9 p.m. on a typical summer day. Gradient boosting decision tree (GBDT) based regression model and linear regression model and their variants with spatial information were constructed and compared for each time instance. Results show that spatially explicit GBDT models had the highest accuracy. Feature importance analysis shows that built form factors such as mean building height were more important during the afternoon, while surface fractions such as road surface fraction had greater influences during the morning and nighttime. Partial dependence plots (PDPs) show that urban form features influence CUHI in a complex nonlinear manner that varies for each time instance. PDPs were further scrutinized based on their activation and threshold effects. GBDT model findings directionally aligned with linear regression, but they provided nuanced insights into the form-CUHI relationship. These findings help planners to better understand the complexity of urban climate and intervention required to reduce CUHI magnitude across the diurnal cycle.

Tracing the informal fringe: A large-scale study of 20th century ‘wild’ settlements in Vienna, Austria

Informal urbanization in the global North is an emerging field of research. Likewise, the need to expand existing morphological analysis into informal settlements is well established but lacks material. As our long-term study is able to show, Vienna was one of the European ‘capitals’ of informal urbanization in the 20th century. Drawing on both historical and present-day geodata and surveys, we trace the emergence and transformation of ‘wild’ settlements over the course of a century. City-wide GIS-reconstructions help us to localize and quantify Vienna's informal fringe. We discuss situational and site factors, the spatial patterns of clearance and legalization.Our research documents the remarkable scale and persistence of Vienna's ‘wild’ settlements. By the mid-1900s, the self-made “city of settlers and gardeners” had transformed more than 43 km2 of peri-urban terrain. Formalization and infrastructural retrofitting were a piecemeal process that lasted until the early 2000s, in some cases even until the present. It resulted in a patchwork of both legal status and urban tissues. The informal ‘facts on the ground’ not only came to structure and shape the residential suburbs of today's agglomeration, but also fed back on the planning instruments and the authorities that tried to enforce them.Informal urbanization in Vienna, as is often the case in the Global South nowadays, was a mode of production of space driven by desires for a better life, for autonomous nutrition and affordable housing. Tracing Vienna's ‘wild’ fringe, we conclude, helps to further demythologize the notion of “Northern formality” and contributes to a small, but growing number of long-term studies on informal (sub)urbanization. Moreover, our study shows that there are ways to reconstruct the settlement patterns of the urban poor even for the pre-google-earth era, provided there is the necessary source material and technical capabilities. Thus, it contributes to the methodological array in urban studies and the study of urban form in general.

From a Grassland to a Bush Capital: A Historic Review of Canberra’s Green Infrastructure Development

Canberra was built in harmony with its landscape setting, creating a legacy of urban form well-connected to the natural environment. Its urban design and planning not only amplified the surrounding natural landscape such as forested hills and mountains but also created a human-made green urban character. However, plans for future development as a compact city pose a challenge to conserving the city’s green spaces. A green infrastructure plan is necessary to consider the city’s green space design heritage and the linked socio-ecological values while minimising the urban footprint. The paper employs a historical literature review to understand the factors and characteristics that shaped Canberra’s green character and the socio-ecological values of its green spaces. The research found the influence of historical and modern design and planning concepts in consolidating green infrastructure and creating ecological corridors and social infrastructure. One of the essential conditions for maintaining the unique character of Canberra is the preservation of the socio-ecological values of its existing green spaces. A trade-off study must be conducted to balance green infrastructure planning while considering these values, in light of development changes.

Evaluation of vertically resolved longwave radiation in SPARTACUS-Urban 0.7.3 and the sensitivity to urban surface temperatures

Abstract. Cities' materials and urban form impact radiative exchanges and surface and air temperatures. Here, the SPARTACUS (Speedy Algorithm for Radiative Transfer through Cloud Sides) multi-layer approach to modelling longwave radiation in urban areas (SPARTACUS-Urban) is evaluated using the explicit DART (Discrete Anisotropic Radiative Transfer) model. SPARTACUS-Urban describes realistic 3D urban geometry statistically rather than assuming an infinite street canyon. Longwave flux profiles are compared across an August day for a 2 km × 2 km domain in central London. Simulations are conducted with multiple temperature configurations, including realistic temperature profiles derived from thermal camera observations. The SPARTACUS-Urban model performs well (cf. DART, 2022) when all facets are prescribed a single temperature, with normalised bias errors (nBEs) &lt;2.5 % for downwelling fluxes, and &lt;0.5 % for top-of-canopy upwelling fluxes. Errors are larger (nBE &lt;8 %) for net longwave fluxes from walls and roofs. Using more realistic surface temperatures, varying depending on surface shading, the nBE in upwelling longwave increases to ∼2 %. Errors in roof and wall net longwave fluxes increase through the day, but nBEs are still 8 %–11 %. This increase in nBE occurs because SPARTACUS-Urban represents vertical but not horizontal surface temperature variation within a domain. Additionally, SPARTACUS-Urban outperforms the Harman single-layer canyon approach, particularly in the longwave interception by roofs. We conclude that SPARTACUS-Urban accurately predicts longwave fluxes, requiring less computational time (cf. DART, 2022) but with larger errors when surface temperatures vary due to shading. SPARTACUS-Urban could enhance multi-layer urban energy balance scheme prediction of within-canopy temperatures and fluxes.

Quantifying urban three-dimensional building form effects on land surface temperature: a case study of Beijing, China

Quantifying urban three-dimensional building form effects on land surface temperature: a case study of Beijing, China

Assessing the influence of neighborhood urban form on outdoor thermal conditions in the hot dry city of Biskra, Algeria

The quality of the thermal urban environment plays a vital role in outdoor human activities and the overall quality of life in residential neighborhoods. This study investigated the influence of two urban form variables, the height to width ratio (H/W) and sky view factor (SVF), on three outdoor thermal environmental parameters (OTEP), direct solar radiation (DSR), mean radiant temperature (MRT), and air temperature (AT) in three neighborhoods in the hot and dry city of Biskra, Algeria. The research followed a three-step process: Three neighborhoods with varying urban form variables were selected, and field measurements of thermal parameters were conducted at various locations during the hottest period of the year. Numerical modeling, simulation, and validation using Envi-met were then performed to gather the remaining outdoor thermal environmental parameters (OTEP; DSR and MRT). Statistical modeling and regression analysis were conducted to investigate the interaction between urban form variables and OTEP. The results showed that increasing the H/W ratio by 1 reduces MRT and AT by 11.79 °C and 1.49 °C, respectively, while decreasing the SVF by 0.1 reduces MRT and AT by 4.173 °C and 0.479 °C, respectively.

Quantifying the impact of urban ventilation corridors on thermal environment in Chinese megacities

In the context of global warming and rapid urbanization, urban wind-heat environment has become increasingly prominent. Although the identification of ventilation corridors has been well investigated, the impact of ventilation corridors on thermal environment remains unclear. Here, we use the single-window algorithm and circuit theory method to analyze the characteristics of land surface temperature (LST) and ventilation corridors in four megacities of China, so as to quantify the effect of ventilation corridors on thermal environment. Results show that circuit theory works well for identifying ventilation corridors. Moreover, we find that spatial distribution of ventilation corridors in one city is remarkably different from another. Interestingly, ventilation corridors, which consist of green spaces, waters, and roads, have a remarkable mitigation effect on thermal environment. LST of each city is mitigated by 2.39 ℃, 3.22 ℃, 2.11 ℃ and 2.60 ℃, respectively, and the cooling intensity in summer is better than that in winter. Thus, it is of great significance to arrange urban form and ventilation corridors to alleviate the impact of high temperature on urban residents.

Does cropland threaten urban land use efficiency in the peri-urban area? Evidence from metropolitan areas in China

In recent decades, cropland policies have been recognized as crucial tools for ensuring food security and managing urban growth. However, whether cropland conservation undermines urban land use efficiency (ULUE) in peri-urban areas has not been adequately studied. This study investigated the impact of cropland on ULUE in the peri-urban areas of 36 rapidly urbanizing metropolitan areas in China. Multiple open-source datasets were used, including land use, land cover, three-dimensional building structure, and nighttime light (NTL) data. Urban construction land patterns (infilling, edge, outlying) were categorized to examine the intermediate role of urban form in the correlation between cropland and ULUE. The findings indicated that: (1) high proportion of cropland area within the peri-urban areas significantly undermined ULUE; (2) although the conservation of cropland is conducive to compact urban growth, the infilling expansion pattern that compelled by cropland conservation would not sustain intensive human activity; and (3) reducing the spatial separation between conserved cropland and urban construction land was conducive to the dual objectives of protecting cropland and promoting ULUE. This study contributed to the development of a nuanced understanding of cropland protection policies that balance national food security and urbanization efficiency.

Study of Urban Thermal Environment and Local Circulations of Guangdong‐Hong Kong‐Macao Greater Bay Area Using WRF and Local Climate Zones

AbstractThe Guangdong‐Hong Kong‐Macao Greater Bay Area (GBA), a cluster of world‐class cities, is undergoing rapid urbanization. However, the heterogeneity of the urban thermal environment resulting from the diversity of urban forms is not yet fully understood. This paper assesses the heterogeneity of the urban heat island (UHI) effect in the GBA using the coupled Weather Research and Forecasting (WRF) model/multi‐layer urban canopy and building energy model (BEP/BEM), with high‐resolution local climate zone (LCZ) map as urban land use/land cover data. The average UHI intensity is found to peak at 1.8 ± 0.4°C in the evening, when the average UHI intensity of LCZ 2 can reach a maximum of 2.4 ± 0.58°C. Properly setting air‐conditioning temperatures can effectively prevent the enhancement of the UHI phenomenon at night by the anthropogenic heat (AH) released from air‐conditioning. The UHI‐induced local circulations and enhanced surface roughness inhibit the penetration of sea breezes inland, and surface wind speed decreases in all LCZs, with a maximum change of more than 0.8 m s−1. However, the increased thermal difference between land and sea leads to enhanced sea breezes offshore, especially in the Pearl River estuary. In addition, a series of sensitivity experiments have been conducted in this paper on initial and boundary conditions, building drag coefficients and urban fractions, which paves the way for further analyzing urban climate in GBA using WRF model and LCZs.

Modelling the impact of urban form on daily mobility energy consumption using archetypal cities

Urban form is regularly identified as a potential key factor for reducing road traffic and the resulting energy consumption, but the nature of the link between mobility and urban form has been subject to considerable debate. This paper employs quantitative research methods to investigate the influence of urban form on daily mobility energy consumption. First, we used archetypal cities, representative of French large-sized cities, which allow us to isolate the impact of urban form and to have more generalised results. Second, we simulated daily mobility in those archetypal cities by using an individual-based daily mobility simulation model, Mobisim-Soft and then calculated the resulting energy consumptions. Our results confirm that the periurban city is the most energy consuming compare to the axialized and the polycentric cities, but it appears that the global structure of an agglomeration is a second-order factor compared to the inner arrangement of its neighbourhoods.

A spatial projection pursuit model for identifying comprehensive urban vitality on blocks using multisource geospatial data

The vitality of city blocks is a crucial indicator of urban development, influenced by human activity, the built environment, and their interconnections. Urban vitality often exhibits agglomeration effects, whereas blocks nearby tend to exhibit similar vitality values. However, existing evaluation methods struggle to effectively account for the spatial correlations among block vitality while simultaneously assessing comprehensive vitality from multiple perspectives. Using Chongqing as a study case, we use multisource geospatial big data to explore the spatial pattern of city block vitality by using a multiobjective optimization spatial projection pursuit model (MOO-SPP). Five dimensions of vitality were conducted and projected into a comprehensive vitality. The results show that (1) the city proper of Chongqing exhibited a "multicenter and multigroup" vitality pattern in terms of comprehensive vitality, and new areas foster several peaks of urban vitality; (2) the spatial distribution of the single-dimensional vitality varies, and enhancing transportation accessibility in the new areas is of utmost importance; (3) there are spatial variation in urban vitality among the districts and blocks, which are influenced by urban form and city polices. This study can provide insights to stakeholders in better understanding the spatial patterns and factors influencing multidimensional block vitality.

The spatial distribution of carbon footprints and engagement in pro-climate behaviors – Trends across urban-rural gradients in the nordics

Climate change mitigation to the 1.5 °C calls for significant and extensive climate actions. Nordic countries are showing high engagement to climate change mitigation while the consumption and lifestyle-based carbon footprints are among the global highest. Majority of global greenhouse gas (GHG) emissions are connected to household consumption where various behavioral changes have been presented in order to reduce the personal carbon footprints. Previous research has shown how behaviors are connected to the living environment and urban structure, which have shown having an impact in forming variations in our lifestyles and behavioral patterns. In this study, with a survey dataset of ∼8000 respondents across the five Nordic countries, the engagement of respondents to different climate and carbon mitigation actions were analyzed and linked to their calculated carbon footprints. Three types of behavioral clusters were found among the respondents, one presenting conscious pro-climate behavior, one relating to frugality behavior, and one cluster related to self-sufficient behavior. The pro-climate behavioral intentions were present more in urbanized areas together with high climate motivation, whereas frugality behavior was level across the urban gradient, and finally respondents from less urbanized areas emphasized self-sufficient behavior. The stated behavioral intentions of the respondents were in contrast to their carbon footprints. Carbon footprints related to leisure consumption were highest in the urban regions and everyday consumption related footprints in the rural regions. Interestingly, only frugality behavior was associated with lower carbon footprints both in everyday and leisure consumption categories, whereas climate conscious behavior was positively related to leisure consumption footprint but negatively related to everyday consumption. The findings emphasize the variation of lifestyles based on different actions in different urban forms where the engagement to climate change mitigation presents differently. The results underline the importance of understanding the role that the built environment plays in being linked to the behavioral patterns and the need to increase the knowledge of the climate impacts of behavioral choices.