Urban Form Measures Research Articles

Insurance Coverage and Flood Exposure in the Gulf of Mexico: Scale, Social Vulnerability, Urban Form, and Risk Measures

Increasing flood losses in the Gulf of Mexico related to development patterns and climate hazards pose serious threats to resilience and insurability. The purpose of this study is to understand how scale, social vulnerability, risk, and urban form relate to National Flood Insurance Program (NFIP) policy coverage and flood exposure. Our multilevel models identify that flooding is significantly clustered by region and counties, especially shoreline counties. Our measures of risk suggest that the Federal Emergency Management Agency (FEMA) special flood hazard area (SFHA) underestimates risk and exposure when compared with the Flood Factor and that there is some compensation in terms of insurance coverage, suggesting a pattern of adverse selection. Older housing stock appears both less insured and less exposed, raising questions of whether current growth patterns are increasing risk independent of environmental change. Our models suggest that census tracts with higher percentages of black residents are less insured and more exposed, and a similar pattern exists for rural areas. Our results highlight the need to seek common solutions across the Gulf of Mexico, concentrating on the most flood-exposed counties, and that specific resilience strategies may be necessary to protect areas with socially vulnerable populations, especially in rural areas. Underlying challenges exist due to the spatial relationship between exposure and social vulnerability and the potential for adverse selection in insurance markets due to different measures of risk.

Mapping urban form into local climate zones for the continental US from 1986–2020

Urbanization has altered land surface properties driving changes in micro-climates. Urban form influences people’s activities, environmental exposures, and health. Developing detailed and unified longitudinal measures of urban form is essential to quantify these relationships. Local Climate Zones [LCZ] are a culturally-neutral urban form classification scheme. To date, longitudinal LCZ maps at large scales (i.e., national, continental, or global) are not available. We developed an approach to map LCZs for the continental US from 1986 to 2020 at 100 m spatial resolution. We developed lightweight contextual random forest models using a hybrid model development pipeline that leveraged crowdsourced and expert labeling and cloud-enabled modeling – an approach that could be generalized to other countries and continents. Our model achieved good performance: 0.76 overall accuracy (0.55–0.96 class-wise F1 scores). To our knowledge, this is the first high-resolution, longitudinal LCZ map for the continental US. Our work may be useful for a variety of fields including earth system science, urban planning, and public health.

National Empirical Models of Air Pollution Using Microscale Measures of the Urban Environment.

National-scale empirical models of air pollution (e.g., Land Use Regression) rely on predictor variables (e.g., population density, land cover) at different geographic scales. These models typically lack microscale variables (e.g., street level), which may improve prediction with fine-spatial gradients. We developed microscale variables of the urban environment including Point of Interest (POI) data, Google Street View (GSV) imagery, and satellite-based measures of urban form. We developed United States national models for six criteria pollutants (NO2, PM2.5, O3, CO, PM10, SO2) using various modeling approaches: Stepwise Regression + kriging (SW-K), Partial Least Squares + kriging (PLS-K), and Machine Learning + kriging (ML-K). We compared predictor variables (e.g., traditional vs microscale) and emerging modeling approaches (ML-K) to well-established approaches (i.e., traditional variables in a PLS-K or SW-K framework). We found that combined predictor variables (traditional + microscale) in the ML-K models outperformed the well-established approaches (10-fold spatial cross-validation (CV) R2 increased 0.02-0.42 [average: 0.19] among six criteria pollutants). Comparing all model types using microscale variables to models with traditional variables, the performance is similar (average difference of 10-fold spatial CV R2 = 0.05) suggesting microscale variables are a suitable substitute for traditional variables. ML-K and microscale variables show promise for improving national empirical models.

Walkability measures to predict the likelihood of walking in a place: A classification and regression tree analysis.

Walkability is a popular and ubiquitous term at the intersection of urban planning and public health. As the number of potential walkability measures grows in the literature, there is a need to compare their relative importance for specific research objectives. This study demonstrates a classification and regression tree (CART) model to compare five familiar measures of walkability from the literature for their relative ability to predict whether or not walking occurs in a dataset of objectively measured locations. When analyzed together, the measures had moderate-to-high accuracy (87.8% agreement: 65.6% of true walking GPS-measured points classified as walking and 93.4% of non-walking points as non-walking). On its own, the most well-known composite measure, Walk Score, performed only slightly better than measures of the built environment composed of a single variable (transit ridership, employment density, and residential density).Thus there may be contexts where transparent and longitudinally available measures of urban form are worth a marginal tradeoff in prediction accuracy. This comparison of walkability measures using CART highlights the importance for public health and urban design researchers to think carefully about how and why particular walkability measures are used.

Expanding in the mountains: spatial patterns of urban form in a rapidly urbanising small city of Vietnam

ABSTRACT Measuring urban form is particularly important in rapidly urbanising countries as it can help assess problems caused by inefficient planning. Despite this, there is a dearth of research on fine-scale measures of urban form in Asia and Vietnam. In this paper, we aim to identify spatial patterns of urban form measured at the intra-urban level in Lào Cai, a provincial capital city in northern Vietnam that has been transformed dramatically since its integration in the Greater Mekong Subregion. We compute 15 indicators of urban form divided into four groups: shapes of built areas, street connectivity, density of services and population, and accessibility. A spatial clustering of the indicators allows to identify five urban form types and their spatial patterns, showing that this small city is experiencing an extensive and fragmented urban growth. We question urbanisation policy underlying such urban form and suggest avenues for a more sustainable urban planning.

The Relationship of Urban Form on Children and Adolescent Health Outcomes: A Scoping Review of Canadian Evidence.

Urban form can have an impact on health outcomes in children, and the synthesis of findings can identify gaps in the literature and regional reviews may help guide policymakers. This study aims to complete a scoping review of the research relating urban form to health outcomes in children and adolescents from urban Canadian settings. Thirteen online databases were searched to identify studies that had objective measures of urban form and health outcomes. Two research assistants independently reviewed 27,444 titles and abstracts, and 176 full-text articles, returning 32 unique studies with youth-specific data. The majority of the included studies were cross-sectional or ecological (n = 26). Six studies used Canada-wide data and the rest were from Ontario (n = 11), Alberta (n = 6), and Quebec (n = 6). Urban form characteristics included neighbourhood food environment (n = 11), parks/natural space/greenness (n = 10), road or intersection characteristics (n = 7), and aggregated urban form measures (n = 7). Studies examined a variety of health outcomes: the majority considered weight status (n = 16) and injury (n = 10). Although there is over-reliance on mainly cross-sectional study designs, there is evidence suggesting that urban form is associated with health outcomes in Canadian youth, with parks/greenspace, road connectivity, and road characteristics most consistently associated with health outcomes in youth.

Urban Form as a Technological Driver of Carbon Dioxide Emission: A Structural Human Ecology Analysis of Onroad and Residential Sectors in the Conterminous U.S.

This study investigates the role of urban form as a technological driver of U.S. CO2 emissions for the onroad and residential sectors. The STIRPAT (Stochastic Impacts by Region on Population, Affluence, and Technology) human structural ecology framework is extended by drawing from science and technology studies (STS) to theorize urban form as a sociotechnical system involving practices and knowledge that contribute to urban land use as a material artifact on the landscape influencing emissions. Questions addressed are: (1) “What is the influence of urban form on total sector CO2 emissions?” and (2) “How does the influence of urban form on CO2 emissions differ for metropolitan versus non-metropolitan status?” Spatial error regression models were estimated using county-level CO2 emissions data from Project Vulcan. The National Land Cover Dataset (NLCD) was used to quantify measures of urban form. Other independent variables were derived from U.S. Census data. Results demonstrate carbon reduction benefits achievable through a developed land use mix containing a greater proportion of high intensity relative to low intensity use. Urban form matters, but it matters differently in terms of sign, significance, and interpretation depending on emission sector and metro versus non-metro status. A focus on urban form provides policymakers potential leverage for carbon mitigation efforts that focus on total emissions as opposed to per capita emission. A feature of the research is its integration of concepts and theory from structural human ecology, STS, land change science, and GIScience.

An analysis of urban form factors driving Urban Heat Island: the case of Izmir

The Urban Heat Island (UHI) effect is a common phenomenon in many cities across the world that has significant socioeconomic and environmental ramifications. Recognizing the significance of taking measures to mitigate the UHI effect, a vast body of research has been published, over the past few decades, on this topic. Existing research covers various climatic contexts and has significantly improved our understanding of the dynamics of the UHI. However, there is a lack of research on the potential linkages between the physical form of urban streets and the UHI effect. The results of such research can be used to develop planning and design strategies for achieving climate-resilient urban development. As a step toward filling this gap, in this study, we use a mixed-methods approach, involving graph theory and spatial statistics to examine the relationship between the UHI effect and selected urban form measures such as street network connectivity, street network centrality, and land-use in Izmir, Turkey. Results show that the UHI effect is more intense in areas with higher levels of street network centrality. On the contrary, higher connectivity of the urban street network is associated with lower levels of the UHI effect.

Towards an Integrated Methodology for Model and Variable Selection Using Count Data: An Application to Micro-Retail Distribution in Urban Studies

Over the last two decades, a growing number of works in urban studies have revealed how micro-retail distribution is significantly related to specific properties of the urban built environment. While a wide variety of urban form measures have been investigated using sophisticated analytical approaches, the same attention has not equally been found in statistical procedures. Several essential features of micro-retail statistical distribution and modelling assumptions are frequently overlooked, compromising the statistical robustness of outcomes. In this work we focus on four main aspects: (i) the discrete, non-negative and highly skewed nature of store distribution; (ii) its zero-inflation; (iii) assessment of the contextual effect; and (iv) the multicollinearity generated by the inclusion of highly related urban descriptors. To overcome these limitations, we propose an integrated methodological framework for both modelling and variable selection assessment based on generalized linear models (GLMs) and elastic-net (Enet) penalized regression (PR), respectively. The procedure is tested via a real case study of the French Riviera, which is described using a large dataset of 105 street-based urban form measures. The outcomes of this procedure show the superiority of the zero-inflate negative binomial count regression approach. A restricted number of urban form properties are found to be related to the micro-retail distribution depending on the specific scale and morphological context under analysis.

Urban Form and Productivity in México 1995-2015

Worldwide, urban policies are encouraging more compact development in cities arguing environmental sustainability and higher economic productivity. However, there is limited evidence for the relationship between urban form and economic productivity outside high-income countries. While we know that workers in larger cities are more productive, existing empirical evidence on the relationship between compactness and productivity is only from high-income countries, with a productive service sector. Given that the economic base of many cities in Mexico consists of land-intensive manufacturing activities, policies promoting urban compactness have potential negative impacts on economic growth by restraining expansion.
 In this paper we explore the relationship in time between urban form/spatial structure and economic productivity in Mexico, by testing the hypothesis that growing in a compact way is positively associated with labor productivity. That hypothesis is not completely rejected because several measures of urban form are positively correlated with higher levels of productivity, and other measures are negatively correlated. As the principal findings are counterintuitive, they raise questions about what is the accepted knowledge of urban growth.
 Keywords: Urban Form; urban structure; productivity; manufacturing; México.

Understanding the role of urban form in explaining transportation and recreational walking among children in a logistic GWR model: A spatial analysis in Istanbul, Turkey

This study aims to examine associations between urban form factors generally, and street network configuration in particular, and walking for different purposes among children in Istanbul, Turkey. Parents of randomly selected students (ages 12–16) at 20 middle schools (N = 917) completed questionnaires about their socio-economic characteristics and the frequency of their children's walking for recreational and for transportation purposes in their neighbourhood during a typical day. The environment around 400 m of participants' homes was evaluated through GIS-based parcel-level land-use data and segment-based street connectivity measures calculated using space syntax techniques. Logistic geographically weighted regression models were estimated to measure the desired associations while adjusting for socio-economic characteristics. Results demonstrate a marginal association between urban form measures and walking behaviour but only in certain peripheral parts of the city. More importantly, increased directional accessibility, which identifies the extent to which more street length is accessible within few direction changes, is associated with higher odds of recreational walking in particular areas where a strong differentiation between scales of street connectivity structure is evident such as a supergrid of primary roads with inserted organic local streets. In addition, children residing in neighbourhoods with reduced residential density and increased commercial and recreational activities are more likely to walk for transportation purposes. The findings of this study demonstrate that the one-size-fits-all approach may not effectively encourage walking. Urban areas tend to have varying qualities that need to be handled uniquely, and therefore targeted rather than blanket interventions regarding the design of neighbourhoods around schools and homes may be beneficial in supporting walking behaviour of children.

Urban performance and density: Generative study on interdependencies of urban form and environmental measures

Majority of the world population live in urban settlements where for the city dwellers, the quality of life is directly influenced by the environmental conditions as a result of the built environment. The environmental conditions on the public realm and in the buildings, shape how people use outdoor and indoor spaces in their daily life. Correspondingly, the present study implements a generative approach to link urban physical density to performative urban design to investigate the environmental impacts of urban morphology. This approach could be beneficial to implement performance-based planning (PBP), as a method for climate change adaptation and environmental resilience, to improve citizens’ wellbeing. Selected performance measures for this study are: nocturnal Urban Heat Island effect, outdoor solar access (for winter and summer) and indoor daylight availability. The results are analyzed based on the mathematical correlations between building form factors and environmental qualities, within varying range of generated building densities. The study shows that, in the case of buildings with square foot print, maximum potential UHI is highly dependent on height of the urban canyon and optimum outdoor solar access during summer is achievable with intermediate canyon width. Daylight variations mainly depend on window to wall ratio (WWR). In addition, with high WWR values (0.7), canyon height and building geometry sequentially have the highest influence on indoor daylight availability.

Urban form, infrastructure and spatial organisation in the Roman Empire

Abstract

From city networks to network economies: Revisiting the effects of urban form in the knowledge-based economy

ABSTRACT The aim of this article is to investigate the relationship between urban form and knowledge–based economies through an example of how the spatial ordering of London’s 19th–century and early 20th–century furniture industry took place. Archival research, quantitative measures of urban form, and geographic information system–based business analytics were combined to test this proposition in 2 areas of London: Shoreditch and Fitzrovia. We hypothesize that the contrast between the spatial structures of the 2 districts contributed to the divergent path development of the furniture industry in these places. Analysis of the social networking of firms is performed and their spatial implications are assessed to determine what kinds of knowledge economies developed over time. In addition, qualitative data, captured through business invoices, are assessed, highlighting the implications on urban policy. This article contributes to the current debate within the field on the opportunities of integrating spatial networks and their use in policy.

Towards Sustainable Urban Spatial Structure: Does Decentralization Reduce Commuting Times?

This paper contributes to the existing debate on the co-location hypothesis, by devising a proximity measure and controlling for a set of other urban form measures. Utilizing the LEHD (Longitudinal Employer–Household Dynamics) Origin-Destination Employment Statistics (LODES) data that provide the number of jobs by a finer geography, this paper measured the degree of centralization, proximity, and job–housing mismatch. Multiple regression analysis revealed that the job–worker proximity leads to a shorter commuting time. In addition, the results focusing on suburban areas revealed that the impact of the job–worker imbalance and the impact of job–worker mismatch on the commuting time are greater in the suburb in comparison with the city center.

From walking buffers to active places: An activity-based approach to measure human-scale urban form

Urban form measures have been increasingly used in multidisciplinary research, yet few studies have conceptualized different meanings of human-scale urban form for various population groups. This study proposes an activity-based approach that builds direct links between urban form measures and travel-activity patterns of various population groups. With a case study on older adults' walking activity in Toronto, this study maps potential activity spaces for each population group, and measures the potential of social interaction at a land-parcel level. Based on a population-representative survey data and an open source routing algorithm, this study provides an exploratory method to conceptualize and measure human-scale urban form for different population groups. Further, this method helps to understand the non-linear relationships between conventional urban form measures and travel-activity patterns, and to inform planning interventions on urban form features that are particularly important for a specific population group.

Understanding the context of neighborhood parks: a method for public space classification

ABSTRACTNeighborhood parks are recognized as key urban public spaces that serve the social, economic, and environmental needs of adjacent neighborhoods. However, relevant studies primarily focus on the contribution of neighborhood parks as discrete spaces, instead of neighborhood parks as built spaces within an urban context. This research provides a better understanding of the inter-relationships between various urban form measures and an alternative way of constructing public space typology based on the surrounding urban form. The research employs factor and cluster analysis to develop a typology of 150 neighborhood park contexts in the City of Chicago, Illinois. 150-neighborhood park surroundings are classified into six categories based on an understanding of the dimensional structure of urban form elements; however, the Chicago Park District currently classifies them into one broad category. The study also provides guidelines for urban design and physical planning strategies for neighborhood park development.

Location Affordability and Regional Economic Resilience: Evidence from the U.S. Foreclosure Crisis

The form and function of cities is in large part defined by the interrelationship between land development and transportation systems. This relationship has important implications for households, including how it shapes economic costs for housing and transportation. Understanding these cost burdens is relevant for transportation agencies that are developing policies, plans, and programs with the intent of improving affordability. This paper presents an analysis of the relationship between high housing cost burdens, high levels of vehicle ownership, demographic characteristics, and mortgage foreclosure. Using data from before the recent U.S. economic crisis, the analysis estimates the effects of pre-crisis characteristics of census tracts and metropolitan regions on foreclosure rates. Multi-dimensional measures of urban form are included to evaluate the effect of metro-level characteristics. The models indicate high shares of Black homeowners, high shares of Hispanic homeowners, and lower income levels are associated with increased foreclosure. Also important is the share of households with high housing cost burdens. High shares of households with high vehicle ownership levels are significantly and positively associated with default and foreclosure. This suggests the costs associated with the ownership of multiple vehicles contributed to households’ economic vulnerability, a vulnerability revealed by mortgage foreclosures. The results for the urban form factors are mixed. Although increased compactness of jobs and housing has a negative effect on foreclosure, increased development intensity across the entire metro region has a positive effect. These differential effects challenge broad-brush assertions of negative impacts of urban sprawl.

Urban form, transit supply, and travel behavior in Latin America: Evidence from Mexico's 100 largest urban areas

This paper examines the relationship between urban form, transportation supply, and individuals' mode choice across Mexico's 100 largest urban areas. After documenting variation in mode choice, urban form, and vehicle ownership, we fit a multinomial logit model to data from 2.5 million commuters who reported a work commute on the 2015 Intercensus. We estimate whether a person commutes by transit, car, or walking/biking as a function of commuters' gender, age, employment status, household income, and seven measures of urban form and transportation supply. Across urban areas, commuters are less likely to drive in dense urban areas where jobs are spatially concentrated jobs and near population centers. Commuters are also less likely to drive in areas with better public transit supply and less roadway. Collectively the measures of urban form are as strongly related to the probability someone commutes to work by car as household income. Population density plays a particularly strongly role with an estimated elasticity four times as strong as recent studies from US urban areas. Taken together, our findings suggest that land use planning and transportation investments can and do influence commute patterns. Recent public policies have almost certainly contributed to increased, rather than decreased driving and associated congestion, pollution, and traffic fatalities.

Assessing Active Living Potential: Case Study of Jacksonville, Florida

Many municipalities in the US are deploying urban planning approaches to resolve problems caused by urban sprawl, particularly the lack of support for physical activity. Although a variety of perspectives on the relationship between physical activity and built environment exist, many studies have suggested objective and reliable measures of urban form that encourage more opportunities for physical activity. Thus, based on the research context, this study builds a Geographic Information System (GIS) model using geospatial dimensions, yields a visualized map ranked by composite scores, and reveals the spatial distribution of quantified cells. Through the Jacksonville case study, it is shown that the GIS-based visualization method provides an expanded set of tools that can help urban planners and public health professionals understand the relationships between urban form and potential for active living. Consequently, these map-based visualized results provide valuable information to health and public policy professionals to coordinate and resolve mutual challenges.