Jung, Meen Chel; Dyson, Karen; Alberti, Marina. (2021). Urban Landscape Heterogeneity Influences the Relationship Between Tree Canopy and Land Surface Temperature. Urban Forestry & Urban Greening, 57.
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Abstract
Urban trees play a key role in alleviating elevated summertime land surface temperatures in cities. However, urban landscape influences the capacity of urban trees to mitigate higher temperatures. We propose that both developed land characteristics and tree cover should be considered to accurately estimate the mitigation effects of canopy cover. We subclassified original land cover based on the canopy cover ratio to capture the within-land cover heterogeneity. We selected two coastal cities with different summertime climatic conditions: Seattle, Washington, USA, and Baltimore, Maryland, USA. We used Landsat-based grid cells (30 m x 30 m) as our spatial analytical unit, with corresponding land surface temperature, canopy area, canopy compactness, population size, and National Land Cover Database (NLCD)-based land cover group. We first used grouped boxplots, Kruskal-Wallis H tests, and post-hoc multiple comparison tests to detect the distribution of land surface temperatures by the land cover group. We then introduced statistical models to test the group effects on the relationship between land surface temperatures and canopy cover variables. We found: (1) land surface temperature increases with level of development, (2) land surface temperature decreases with canopy cover level, (3) the magnitude of the mitigation effects from canopy area differs based on development level and current canopy cover, (4) the differing efficacies of canopy area in decreasing land surface temperature follows a nonlinear threshold relationship, and (5) compactness of canopy cover was not significant in reducing the land surface temperature. These findings suggest the importance of considering heterogeneous canopy cover within developed land cover classes in urban heat island research. Tree planting strategies need to consider the nonlinear relationships between tree canopy cover and land surface temperature alongside environmental equity concerns.
Keywords
Extreme Heat Events; Climate-change; Cover Data; Island; Pattern; Cities; Vegetation; Mortality; Phoenix; Impact; Canopy Cover; Environmental Equity; Land Cover; Land Surface Temperature; Mitigation Effect; Area; Canopy; Cells; Climatic Factors; Databases; Heat Island; Landscapes; Multiple Comparison Test; Planting; Population Size; Research; Statistical Models; Summer; Surface Temperature; Testing; Trees; Urban Forestry; Maryland
Zou, Tianqi; Aemmer, Zack; Mackenzie, Don; Laberteaux, Ken. (2022). A Framework for Estimating Commute Accessibility and Adoption of Ridehailing Services Under Functional Improvements from Vehicle Automation. Journal Of Transport Geography, 102.
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Abstract
This paper develops an analytical framework to estimate commute accessibility and adoption of various ridehailing service concepts across the US by synthesizing individual commute trips using national Longitudinal Employer-Household Dynamics Origin-Destination Employment Statistics (LODES) data. Focusing on potential improvements in cost and time that could be enabled by vehicle automation, we use this modeling framework to simulate a lower-price autonomous service (e.g., 50% or 75% lower) with variable wait times and implementation levels (solo, pooled, and first/last mile transit connections services, alone or in combination) to determine how they might affect adoption rates. These results are compared across metrics of accessibility and trip density, as well as socioeconomic factors such as household income. We find - unsurprisingly - that major cities (e.g. New York, Los Angeles, and Chicago) support the highest adoption rates for ridehailing services. Decreases in price tend to increase market share and accessibility. The effect of a decrease in price is more drastic for lower income groups. The proposed method for synthesizing trips using the LODES contributes to current travel demand forecasting methods and the proposed analytic framework can be flexibly implemented with any other mode choice model, extended to non-commute trips, or applied to different levels of geographic aggregation.
Keywords
Choice Of Transportation; Demand Forecasting; Poor People; Adoption; Price Cutting; Metropolis; Employment Statistics; Los Angeles (calif.); New York (state); Chicago (ill.); Accessibility; Autonomous Vehicles; New Mobility Services; Ridehailing; Travel Demand; Preferences
Pan, Haixiao; Shen, Qing; Xue, Song. (2010). Intermodal Transfer Between Bicycles and Rail Transit in Shanghai, China. Transportation Research Record, 2144, 181 – 188.
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Abstract
Large cities in China are building rail transit systems as part of a key strategy to address their pressing urban transportation problems. Because the high construction cost of subways and light rail limits the network density of rail transit, urban transport planners must seek effective intermodal connections between rail and other modes. This research examines the challenges and opportunities for improving the bicycle rail connection by using Shanghai as a case study. On the basis of two questionnaire surveys of rail transit riders, the research analyzes the existing mode shares of rail station access and egress trips, the underlying mechanisms for choosing among alternative modes, and the comparative advantages of the bicycle for trips that have certain distance and location characteristics. Empirical results suggest that the potential for travel improvement for rail transit riders lies primarily in the collection and distribution phases. Results point to several promising approaches to improving the bicycle rail connection and utilizing the bicycle more fully as an efficient supplement mode for the rapidly expanding urban rail transportation in China. In addition, the work can be a useful reference for cities in other countries in which rail transit development is accompanied by the continued importance of bicycles in residents' travel.
Duncan, Glen E.; Dansie, Elizabeth J.; Strachan, Eric; Munsell, Melissa; Huang, Ruizhu; Moudon, Anne Vernez; Goldberg, Jack; Buchwald, Dedra. (2012). Genetic and Environmental Influences on Residential Location in the US. Health & Place, 18(3), 515 – 519.
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Abstract
We used a classical twin design and measures of neighborhood walkability and social deprivation, using each twin's street address, to examine genetic and environmental influences on the residential location of 1389 same-sex pairs from a US community-based twin registry. Within-pair correlations and structural equation models estimated these influences on walkability among younger (ages 18-24.9) and older (ages 25+) twins. Adjusting for social deprivation, walkability of residential location was primarily influenced by common environment with lesser contributions of unique environment and genetic factors among younger twins, while unique environment most strongly influenced walkability, with small genetic and common environment effects, among older twins. Thus, minimal variance in walkability was explained by shared genetic effects in younger and older twins, and confirms the importance of environmental factors in walkability of residential locations. (c) 2012 Elsevier Ltd. All rights reserved.
Keywords
Homesites; Community Life -- Social Aspects; Structural Equation Modeling; Genetics; Analysis Of Variance; Environmental Health; Walking; United States; Environment; Neighborhood; Twins; Walkability; Physical-activity; Twin Registry; Epidemiology; Preferences; Selection; Zygosity
Moudon, Anne Vernez; Drewnowski, Adam; Duncan, Glen E.; Hurvitz, Philip M.; Saelens, Brian E.; Scharnhorst, Eric. (2013). Characterizing the Food Environment: Pitfalls and Future Directions. Public Health Nutrition, 16(7), 1238 – 1243.
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Abstract
Objective: To assess a county population's exposure to different types of food sources reported to affect both diet quality and obesity rates. Design: Food permit records obtained from the local health department served to establish the full census of food stores and restaurants. Employing prior categorization schemes which classified the relative healthfulness of food sources based on establishment type (i.e. supermarkets v. convenience stores, or full-service v. fast-food restaurants), food establishments were assigned to the healthy, unhealthy or undetermined groups. Setting: King County, WA, USA. Subjects: Full census of food sources. Results: According to all categorization schemes, most food establishments in King County fell into the unhealthy and undetermined groups. Use of the food permit data showed that large stores, which included supermarkets as healthy food establishments, contained a sizeable number of bakery/delis, fish/meat, ethnic and standard quick-service restaurants and coffee shops, all food sources that, when housed in a separate venue or owned by a different business establishment, were classified as either unhealthy or of undetermined value to health. Conclusions: To fully assess the potential health effects of exposure to the extant food environment, future research would need to establish the health value of foods in many such common establishments as individually owned grocery stores and ethnic food stores and restaurants. Within-venue exposure to foods should also be investigated.
Keywords
Food Chemistry; Obesity; Health Boards; Dietary Supplements; Food Cooperatives; Restaurant Reviews; Coffee Shops; Food Consumption; Food Quality; Census Of Food Sources; Exposure; Health Value; Neighborhood Characteristics; Store Availability; Racial Composition; Physical-activity; Weight Status; Restaurants; Association; Proximity; Access; Business Enterprises; Fast Food Restaurants; Fish; Grocery Stores; Healthy Diet; Meat; Nutritional Adequacy; Supermarkets
Purcell, Mark. (2014). Possible Worlds: Henri Lefebvre and the Right to the City. Journal Of Urban Affairs, 36(1), 141 – 154.
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Abstract
There has been much attention paid recently the idea of the right to the city. This article argues that in order to fully appreciate the power of the idea, we should understand it through a close reading of Henri Lefebvre's body of work on the city and politics. Lefebvre presents a radical vision for a city in which users manage urban space for themselves, beyond the control of both the state and capitalism. However, while it calls for profound change, Lefebvre's vision is also eminently practical; it can very much serve as a guide and inspiration for concrete action to change the city today.
Kang, Bumjoon; Scully, Jason Y.; Stewart, Orion; Hurvitz, Philip M.; Moudon, Anne V. (2015). Split-Match-Aggregate (SMA) Algorithm: Integrating Sidewalk Data with Transportation Network Data in GIS. International Journal Of Geographical Information Science, 29(3), 440 – 453.
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Abstract
Sidewalk geodata are essential to understand walking behavior. However, such geodata are scarce, only available at the local jurisdiction and not at the regional level. If they exist, the data are stored in geometric representational formats without network characteristics such as sidewalk connectivity and completeness. This article presents the Split-Match-Aggregate (SMA) algorithm, which automatically conflates sidewalk information from secondary geometric sidewalk data to existing street network data. The algorithm uses three parameters to determine geometric relationships between sidewalk and street segments: the distance between streets and sidewalk segments; the angle between sidewalk and street segments; and the difference between the lengths of matched sidewalk and street segments. The SMA algorithm was applied in urban King County, WA, to 13 jurisdictions' secondary sidewalk geodata. Parameter values were determined based on agreement rates between results obtained from 72 pre-specified parameter combinations and those of a trained geographic information systems (GIS) analyst using a randomly selected 5% of the 79,928 street segments as a parameter-development sample. The algorithm performed best when the distances between sidewalk and street segments were 12m or less, their angles were 25 degrees or less, and the tolerance was set to 18m, showing an excellent agreement rate of 96.5%. The SMA algorithm was applied to classify sidewalks in the entire study area and it successfully updated sidewalk coverage information on the existing regional-level street network data. The algorithm can be applied for conflating attributes between associated, but geometrically misaligned line data sets in GIS.
Keywords
Geodatabases; Sidewalks; Algorithms; Pedestrians; Digital Mapping; Algorithm; Gis; Pedestrian Network Data; Polyline Conflation; Sidewalk; Built Environment; Physical-activity; Mode Choice; Urban Form; Land-use; Travel; Generation; Walking
Estiri, Hossein. (2016). Differences in Residential Energy Use between US City and Suburban Households. Regional Studies, 50(11), 1919 – 1930.
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Abstract
This paper applies path analysis to household-level data from the US residential sector to study differences in energy consumption between self-identified city and suburban households. Results show that, on average, suburban households consume more energy in residential buildings than their city-dweller counterparts. This variation in energy consumption is due to differences in: (1) characteristics of the household and the housing unit, independently, and (2) interactions between the household and housing characteristics in the city and suburban households. Findings of this study provide new insights into how regional policies can be implemented differently in suburbs and cities to reduce energy consumption.
Keywords
Urban Form; Electricity Consumption; Land-use; Impact; Sector; Sprawl; Determinants; Appliance; Mobility; Density; Energy Use; Residential Sector; City-dwellers; Suburbanites; Households; Path Analysis; Suburban Areas; Cities; Housing; Energy Consumption; Comparative Analysis; Data Processing; Residential Energy; Suburbs; Residential Buildings; Residential Areas; Energy Policy; Regional Analysis; Regional Studies; United States--us
Stewart, Orion T.; Carlos, Heather A.; Lee, Chanam; Berke, Ethan M.; Hurvitz, Philip M.; Li, Li; Moudon, Anne Vernez; Doescher, Mark P. (2016). Secondary GIS Built Environment Data for Health Research: Guidance for Data Development. Journal Of Transport & Health, 3(4), 529 – 539.
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Abstract
Built environment (BE) data in geographic information system (GIS) format are increasingly available from public agencies and private providers. These data can provide objective, low-cost BE data over large regions and are often used in public health research and surveillance. Yet challenges exist in repurposing GIS data for health research. The GIS data do not always capture desired constructs; the data can be of varying quality and completeness; and the data definitions, structures, and spatial representations are often inconsistent across sources. Using the Small Town Walkability study as an illustration, we describe (a) the range of BE characteristics measurable in a GIS that may be associated with active living, (b) the availability of these data across nine U.S. small towns, (c) inconsistencies in the GIS BE data that were available, and (d) strategies for developing accurate, complete, and consistent GIS BE data appropriate for research. Based on a conceptual framework and existing literature, objectively measurable characteristics of the BE potentially related to active living were classified under nine domains: generalized land uses, morphology, density, destinations, transportation system, traffic conditions, neighborhood behavioral conditions, economic environment, and regional location. At least some secondary GIS data were available across all nine towns for seven of the 9 BE domains. Data representing high-resolution or behavioral aspects of the BE were often not available. Available GIS BE data - especially tax parcel data often contained varying attributes and levels of detail across sources. When GIS BE data were available from multiple sources, the accuracy, completeness, and consistency of the data could be reasonable ensured for use in research. But this required careful attention to the definition and spatial representation of the BE characteristic of interest. Manipulation of the secondary source data was often required, which was facilitated through protocols. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords
Geographic Information-systems; Physical-activity; Land-use; Walking; Neighborhood; Associations; Density; Design; Adults; Travel; Active Travel; Pedestrian; Urban Design; Community Health; Rural
Huang, Ruizhu; Moudon, Anne V.; Zhou, Chuan; Stewart, Orion T.; Saelens, Brian E. (2017). Light Rail Leads to More Walking Around Station Areas. Journal Of Transport & Health, 6, 201 – 208.
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Abstract
Areas around Light Rail Transit (LRT) stations offer ideal conditions for Transit-Oriented Development (TOD). Relatively dense, mixed-use neighborhoods can have positive impacts on mobility, health, and perceptions of neighborhood safety among nearby residents, primarily through walking activity for both transit and other purposes. To examine how station areas may attract new activity, this study analyzed changes in walking around station areas among people living close to an LRT station before and after the opening of a new transit system. This study examined walking behavior among the subset of 214 participants living within one mile of one of 13 LRT stations from among a sample of residents living close or further away from a new LRT line in Seattle. They completed a survey and a travel log and wore an accelerometer and a GPS for 7 days both before (2008) and after the opening of the Seattle area LRT (2010). Walking bouts were derived using a previously developed algorithm. The main outcome was the individual-level change in the proportion of daily walking within one quarter Euclidean mile of an LRT station. Overall walking decreased from before to after the LRT opening while station area walking did not change significantly, indicating a shift in walking activity to the station areas after the introduction of LRT. Increases in the proportion of station area walking were negatively related to participants' distance between home and the nearest LRT station, peaking at .0.75 mile. Male gender, college education, normal weight status, less access to cars, and frequent LRT use were also significantly associated with greater positive changes in the proportion of station area walking. The shift in walking to station areas after the completion of light rail provides evidence that the local proximate population is attracted to station areas, which may potentially benefit both transit use and TOD area economic activity. The residential catchment area for the shift in LRT area walking was < 0.75 mile of the LRT stations. (C) 2017 Elsevier Ltd All rights reserved.
Keywords
Body-mass Index; Physical-activity; Built Environment; Travel Behavior; Transit; Stop; Transit Oriented Development (tod); Behavior Change; Global Positioning Systems; Geographic Information Systems