Jun Hyun Kim

Assessing Benefits of Neighborhood Walkability to Single-Family Property Values A Spatial Hedonic Study in Austin, Texas

This article investigates the impact of neighborhood walkability, measured by Street Smart Walk Score and sidewalk density, on property values by analyzing the 2010–2012 single-family home sale transactions in Austin, Texas. The Cliff-Ord spatial hedonic model (also known as the General Spatial Model, or SAC) is used to control for spatial autocorrelation effects. Results show that improving walkability through increased access to amenities in car-dependent neighborhoods does not appear to increase property values; adding sidewalks in these neighborhoods leads to a minimal increase in property values. Investments in neighborhood amenities and sidewalks will yield a greater home price increase in a walkable neighborhood than in a car-dependent neighborhood.

Urban Natural Environments, Obesity, and Health-Related Quality of Life among Hispanic Children Living in Inner-City Neighborhoods

Although a substantial body of literature has provided evidence supporting the positive effects of natural environments on well-being, little has been known about the specific spatial patterns of urban nature in promoting health-related quality of life (HRQOL) among children. This study assessed the association that the urban natural environment measured by landscape spatial patterns may have with obesity and HRQOL among Hispanic children. Ninety-two 4th and 5th grade students were recruited from Houston, Texas, and the Pediatric Quality of Life Inventory (PedsQL) was used to capture the children’s HRQOL. The quality of urban natural environments was assessed by quantifying the landscape spatial patterns, using landscape indices generated by Geographic Information Systems and remote sensing. From the bivariate analyses, children’s body mass index showed a significantly negative association with their HRQOL. After controlling for socio-demographic factors, the results revealed that larger and more tree areas were positively correlated with children’s HRQOL. In addition, those children living in areas with tree patches further apart from each other showed higher HRQOL. This research adds to the current multi-disciplinary area of research on environment-health relationships by investigating the roles of urban greeneries and linking their spatial structures with children’s HRQOL.

The role of landscape spatial patterns on obesity in Hispanic children residing in inner-city neighborhoods

BACKGROUND Childhood obesity and its comorbidities have become major public health challenges in the US. While previous studies have investigated the roles of land uses and transportation infrastructure on obesity, limited research has examined the influence of landscape spatial patterns. The purpose of this study was to examine the association between landscape spatial patterns and obesity in Hispanic children. METHODS Participants included 61 fourth- and fifth-grade Hispanic children from inner-city neighborhoods in Houston, TX. BMI z-scores were computed based on objectively-measured height and weight from each child. Parental and child surveys provided sociodemographic and physical activity data. Landscape indices were used to measure the quality of landscape spatial patterns surrounding each childs home by utilizing Geographic Information Systems and remote sensing analyses using aerial photo images. RESULTS After controlling for sociodemographic factors, in the half-mile airline buffer, more tree patches and well-connected landscape patterns were negatively correlated with their BMI z-scores. Furthermore, larger sizes of urban forests and tree patches were negatively associated with childrens BMI z-scores in the half-mile network buffer assessment. CONCLUSIONS This study suggests that urban greenery requires further attention in studies aimed at identifying environmental features that reduce childhood obesity.

Hispanic Maternal and Children's Perceptions of Neighborhood Safety Related to Walking and Cycling

This study examined neighborhood safety as perceived by children (mean age=10 years) and their mothers, and its association with childrens physical activity. For all eight safety items examined, children perceived their environment as less dangerous than mothers (p<0.05). None of the multiple regression models predicting childrens physical activity by safety perceptions were significant (p>0.10). The maternal perception model explained the highest percentage of variance (R(2)=0.26), compared to the childrens perception model (R(2)=0.22). Findings suggest that future studies should explore relations between self-reported and objectively measured safety barriers to Hispanic youth walking and cycling.

Neighborhood Landscape Spatial Patterns and Land Surface Temperature: An Empirical Study on Single-Family Residential Areas in Austin, Texas

Rapid urbanization has accelerated land use and land cover changes, and generated the urban heat island effect (UHI). Previous studies have reported positive effects of neighborhood landscapes on mitigating urban surface temperatures. However, the influence of neighborhood landscape spatial patterns on enhancing cooling effects has not yet been fully investigated. The main objective of this study was to assess the relationships between neighborhood landscape spatial patterns and land surface temperatures (LST) by using multi-regression models considering spatial autocorrelation issues. To measure the influence of neighborhood landscape spatial patterns on LST, this study analyzed neighborhood environments of 15,862 single-family houses in Austin, Texas, USA. Using aerial photos, geographic information systems (GIS), and remote sensing, FRAGSTATS was employed to calculate values of several landscape indices used to measure neighborhood landscape spatial patterns. After controlling for the spatial autocorrelation effect, results showed that larger and better-connected landscape spatial patterns were positively correlated with lower LST values in neighborhoods, while more fragmented and isolated neighborhood landscape patterns were negatively related to the reduction of LST.

From car-dependent neighborhoods to walkers' paradise: Estimating walkability premiums in the condominium housing market

Movement toward compact and walkable communities and low-carbon travel has gained momentum through various policy initiatives. However, residents’ willingness to pay for neighborhood walkability is still unknown. This study addresses that knowledge gap by quantifying walkability premiums based on 3,899 condominium sale transactions from 2010 to 2012 in Austin, Texas. Two measures of walkability were compared: Walk Score and Street Smart Walk Score. A spatial hedonic modeling approach improved estimation accuracy by controlling for spatial autocorrelation effects. The premium for walkability was found to be influenced by the pedestrian collision rate, street connectivity, length of sidewalks, speed limit, and various sociodemographic factors. A positive walkability premium was identified for 57% of sampled condominiums, most of which were located in neighborhoods that were at least somewhat walkable. The results could be used to identify investment priorities for creating walkable neighborhoods.

The influence of urban landscape spatial patterns on single-family housing prices

Many empirical studies assessing the economic benefits of urban green space have continually documented that green space tends to increase both value and sale price of nearby residential properties. Previous studies, however, have not fully captured the quality of neighborhood level landscape spatial patterns on housing prices. To fill this literature gap, this study examined the association between landscape spatial patterns of urban green spaces and single-family home sale transactions using a spatial regression model. The research was conducted through the analysis of 11,326 housing transaction records from 2010 to 2012 in Austin, TX, USA. Variables measuring the structural, locational and neighborhood characteristics of housing were coupled with Geographic Information Systems, remote sensing and FRAGSTATS to calculate several landscape indices measuring the quality of existing landscape spatial patterns. After controlling for any spatial autocorrelation effects, we found that that larger tree and urban forest areas surrounding single-family homes positively contributed to property values, while more fragmented, isolated and irregularly shaped landscape spatial patterns resulted in the inverse. The results of this research increase awareness of the role of urban green spaces while informing community design/planning practices about the linkages between landscape spatial structure and economic benefits.

Low-impact development for impervious surface connectivity mitigation: assessment of directly connected impervious areas (DCIAs)

Urbanization increases directly connected impervious area (DCIA), the impervious area that is hydraulically connected to downstream drainage by closed pipelines. Although the benefits of low-impact development (LID) have been examined in other studies, its effect on alleviating DCIA levels has seldom been assessed. This study measured the DCIA of urban watersheds in Houston, TX, USA. Five land-use types were categorized and the contribution of LID facilities to reducing DCIA in each type was estimated by using Sutherlands equations. The results showed (1) DCIA in commercial areas was greater than that in residential areas, especially for big-box retailers; (2) the percentage of DCIA reduction by LID varied by land-use type; and (3) optimal combinations of LID application could maximize the effectiveness of DCIA reduction. The results contribute to prioritizing land-use type for implementing LID practices and providing local governments with a useful measure to estimate runoff volume.

Sidewalk Landscape Structure and Thermal Conditions for Child and Adult Pedestrians

Walking is being promoted for health and transportation purposes across all climatic regions in the US and beyond. Despite this, an uncomfortable microclimate condition along sidewalks is one of the major deterrents of walking, and more empirical research is needed to determine the risks of heat exposure to pedestrians while walking. This study examined the effect of street trees and grass along sidewalks on air temperatures. A series of thermal images were taken at the average heights of adults and children in the US to objectively measure the air temperatures of 10 sidewalk segments in College Station, TX, USA. After controlling the other key physical environmental conditions, sidewalks with more trees or wider grass buffer areas had lower air temperatures than those with less vegetation. Children were exposed to higher temperatures due to the greater exposure or proximity to the pavement surface, which tends to have higher radiant heat. Multivariate regression analysis suggested that the configuration of trees and grass buffers along the sidewalks helped to promote pleasant thermal conditions and reduced the differences in ambient air temperatures measured at child and adult heights. This study suggests that street trees and vegetated ground help reduce the air temperatures, leading to more thermally comfortable environments for both child and adult pedestrians in warm climates. The thermal implications of street landscape require further attention by researchers and policy makers that are interested in promoting outdoor walking.