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Article

Investigation of the Microenvironment, Land Cover Characteristics, and Social Vulnerability of Heat-Vulnerable Bus Stops in Knoxville, Tennessee

by
Sangwon Lee
* and
Jennifer M. First
College of Social Work, University of Tennessee, Knoxville, TN 37996, USA
*
Author to whom correspondence should be addressed.
Sustainability 2023, 15(14), 10866; https://doi.org/10.3390/su151410866
Submission received: 9 June 2023 / Revised: 8 July 2023 / Accepted: 10 July 2023 / Published: 11 July 2023
(This article belongs to the Section Environmental Sustainability and Applications)
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Abstract

:
The urban heat island is a climate, public health, and environmental justice issue. Sustainable urban infrastructure needs improvements in public transport to protect citizens’ health from the urban heat island. This case study investigates the local microenvironment and social vulnerability of heat-vulnerable bus stops in Knoxville, Tennessee, using publicly available data from a variety of sources. These included ground and satellite measurements of heat and humidity from the Knoxville Heat Mapping Campaign, characteristics of land surface from the National Land Cover Dataset 2019 of the United States Geological Survey, and the 2018 Social Vulnerability Index from the U.S. Centers for Disease Control and Prevention. A geographic information system and a principal component analysis were used to identify social vulnerability in areas where the bus stops are located. The results show that most heat-vulnerable bus stops are poor microenvironments without trees and shelters. The hottest bus stops are concentrated in the highly developed and densely populated areas of West Knoxville and downtown Knoxville and in South, North, Northeast, and Northwest Knoxville, which are relatively high vulnerability clustered and have poor public infrastructure. The findings provide the foundation for mitigation strategies to better prepare local communities for climate change by identifying public transportation areas negatively impacted by the urban heat island.

1. Introduction

Climate change can exacerbate existing urban quality of life challenges, including social inequality, deteriorating infrastructure, and ecological stress [1]. The combination of rising average temperatures due to climate change and urbanization contributes to an intensified “Urban Heat Island (UHI)”, where temperatures in cities are higher than in suburbs or rural areas [2]. The UHI effect occurs when heat is absorbed and re-radiated due to the conditions associated with the built environment, such as the impervious surface concentration and loss of tree and canopy cover, creating a heat pocket or “heat island” [3]. UHIs contribute to the intensity and duration of extreme heat, which in turn increases heat-related health risks and fatality rates caused by heat stress [4]. Extreme heat causes more deaths (around 1500 per year) than other severe weather events in the United States [5]. The majority of heat-related deaths in the United States over the past 15 years have happened in the 175 largest cities, which account for 65% of the country’s population [6].
The UHI is a climate, public health, and environmental justice issue [7]. Due to discriminatory policies such as redlining, there are currently disparities in exposure to intra-urban heat [8]. Redlining was one of the policies that formalized racial and ethnic segregation and further cemented housing segregation that has linked disparities in income, education, community infrastructure, built environments, and declining home values [9,10,11,12]. All of these contribute to the communities’ poor performance during extreme heat, lack of heat mitigation amenities, and higher levels of exposure to ambient heat [13]. For example, the proportion of trees and canopies critical to mitigating UHIs is lower in areas populated primarily by Black/African Americans, Hispanics/Latinos, and low-income populations [13,14].
To improve the development of more resilient cities and protect the health of citizens from the UHIs, sustainable urban infrastructure requires improvements in public transportation [15,16]. Equity-related principles like a good public transport system are relevant for urban resilience linked with public health, social service provision, urban development, and integrating social justice [17]. So far, policies on the relationship between public transport and UHIs have focused on reducing emissions and preventing environmental pollution by increasing commuters’ options for using public transportation [18,19,20]. The policy is characterized by access to general urban landscapes rather than focusing on specific areas and populations vulnerable to the UHI. However, health burden from extreme heat is disproportionately increased in groups physiologically sensitive to heat events or with fewer adaptive resources, such as older adults, people with less income, and less social connectivity [21]. These socioeconomic and demographic factors, described as the social vulnerability related to the interaction of hazards of place (risk and mitigation) with the communities’ social vulnerability profile [22,23], could help explain the disparities in heat-related health risks [8].
Considering that the effects of the UHI vary between regions and populations [24,25], and systematically marginalized populations are more likely to rely on public transport not only to get to work but also to access the many activities such as traveling to child care providers and health care facilities that are required to maintain employment [26,27], it is essential to identify areas and populations that are more vulnerable to heat and the intersections of public transport infrastructure and social vulnerabilities. Despite the increased risk of heat exposure from using public transport, not many studies have linked the public transport infrastructure and the social vulnerability of at-risk areas and adaptive strategies to mitigate the UHI.
Hazard risk (i.e., the spatial distribution of potential harm), exposure (i.e., the intersection of the spatial distribution of human populations with the hazard), and vulnerability (i.e., the propensity to suffer harm when exposed to the hazard) are the three components that typically make up an environmental risk analysis [4]. A comprehensive examination of the spatial characteristics of heat-vulnerable areas, the degree and distribution of heat, and the intersection of social vulnerabilities of at-risk populations can help to explain structural and spatial inequality and understand the effects of extreme heat in urban areas. Also, this knowledge can provide a foundation for research on the adaptive capacity of citizens and community resources to respond to the UHI effects.
This pilot study aims to conduct a preliminary investigation to identify social vulnerability, exposure and sensitivity to heat, and adaptive capacity to mitigate the UHI effect of citizens who use public transportation in Knoxville, Tennessee. In addition, this study may be expected as a foundation for future problem-solving work to address heat vulnerability and public transit infrastructure in communities through suitability modeling, including additional variables (e.g., micro-scale built environment, population, and number of bus passengers). The research questions are as follows.
Q1. Which bus stops in Knoxville, Tennessee, are more vulnerable to heat?
Q2. What are the patterns of social vulnerability in the areas where the heat-vulnerable bus stops are located?

2. Methods

2.1. Study Area

Knoxville is the third largest city in Tennessee, with a population of about 192,648 in 2021 [28]. It is located at the western foot of the Great Smoky Mountains, part of the Appalachian Mountains in eastern Tennessee. Knoxville’s average temperatures range is from −3.3~11.7 °C in the winter to 13.9~30.6 °C in the summer, with an average of 34 days per year of extreme heat (≥ to 32.2 °C) and 68 days per year of extreme cold (≤0 °C). The average rainfall is 131.9 cm [29]. In the years between 1985 and 2005, residents in Knoxville experienced about seven days above 33.9 °C per year. By 2050, people in Knoxville will experience an average of about 46 days per year over 33.9 °C [30]. The city’s population is predominantly white (74.9%), with 16.4% Black/African Americans and 5.7% Latino/Hispanic population. The median household income is $44,308, $23,192 less than the national average of $67,500 [28].

2.2. Data Acquisition and Processing

This study is based on three data sources: (ⅰ) satellite and ground measurements of heat and humidity from the Knoxville Heat Mapping Campaign were used to identify heat-vulnerable bus stops; (ⅱ) characteristics of land surface from the National Land Cover Dataset 2019 (NLCD 2019) of the United States Geological Survey (USGS) were used to identify land cover characteristics and presence of trees in the identified bus stops; and (ⅲ) the 2018 Social Vulnerability Index (SVI) from the U.S. Centers for Disease Control and Prevention (CDC) was used to examine patterns of social vulnerability in census tracts of where the heat-vulnerable bus stops are located. The SVI is derived from 15 variables at the census tract level, which include socioeconomic and demographic characteristics, including the percentage of people below in poverty level, the employment rate, educational attainment, race and ethnicity, first language spoken, housing crowding, and availability of transportation.

2.2.1. Bus Stop with the Highest Temperature and Heat Index

To identify which bus stops in Knoxville were more vulnerable to heat, we identified the bus stop with the highest temperature and heat index (HI, i.e., a measure that combines air temperature and relative humidity to posit a human-perceived equivalent temperature, which is an important consideration for the human body’s comfort) in Knoxville, using heat maps and bus stop point data in ArcGIS Pro (version 2.8.0).
The raster files of six heat maps (morning, afternoon, evening temperatures and morning, afternoon, and evening HI for Knoxville) were obtained from the Knoxville Heat Equity Coalition website’s ‘2022 Knoxville’s Heat Mapping Report’ [31]. In August 2022, Knoxville community members drove nine routes over a 269.4 km2 area across the city to collect temperature data three times per day (6:00–7:00 a.m., 3:00–4:00 p.m., and 7:00–8:00 p.m.) and acquired results, including 58,264 measurements. The points of Knoxville Area Transit (KAT) bus stops were geo-processed to identify the most heat-vulnerable bus stops. The shapefiles for the KAT bus stop data were obtained from the General Transit Feed Specification available on the City of Knoxville website [32].

2.2.2. Microenvironment of Bus Stops

At the micro-scale, the built environment of transit infrastructure consists of 58 features in six components (i.e., land use environment, transportation environment, facilities, aesthetics, signage, and social environment) [33]. Among the elements that make up the microenvironment of public transportation, this study focused on the land use environment by examining land cover characteristics and the presence of trees and shelters.
The NLCD 2019 of the United States Geological Survey [34] was mapped to examine the characteristics of the land surface where the bus stop is located. The NLCD 2019 includes 28 different land cover classes characterizing land cover and land cover change. ArcGIS Pro (version 2.8.0) was used to map the raster data of the NLCD. Trees and shelters at bus stops have been found to protect bus users from extreme heat when using public transport [35,36]. We acquired data from the USDA’s 2021 National Agriculture Imagery Program (NAIP) County Mosaic (60 cm spatial resolution). We mapped it to examine bus stops with shelters and trees [37]. ArcGIS Pro (version 2.8.0) was used to map the raster data of the NAIP raster data. Also, we took pictures at some bus stops to identify if there were trees and shelters.

2.2.3. Social Vulnerability

The 2018 Social Vulnerability Index (SVI) from the U.S. Centers for Disease Control and Prevention (CDC) was analyzed to investigate patterns of social vulnerability in areas where bus stops are located.
First, the U.S. Census Bureau’s TIGER/Line Files shapefile [38] was mapped to identify census tracts with heat-vulnerable bus stops and their neighborhoods (i.e., census tracts inhabited by populations expected to use the identified bus stops). Subsequently, ten variables in the four important vulnerability aspects (i.e., Socioecononic status, household characteristics, racial and ethnic minority status, housing, and transportation) related to extreme weather events were determined from the 2018 SVI based on prior research [39,40,41,42]. The variables were analyzed by PCA (principal component analysis) method to identify the patterns of social vulnerability in the identified areas [43]. See Table 1 for the variables of SVI used in the analysis.
By transforming correlated variables into linearly uncorrelated principal components, PCA simplifies the complexity of high-dimensional data while retaining trends and patterns [44]. Therefore, PCA is frequently used in heat vulnerability studies to reduce the dimensionality of data [45]. Kaiser criteria (for eigenvalues > 1) and a stepwise exclusion method were used to reorganize the multi-correlated attributes using a varimax rotation in SPSS (version 28.0). Bartlett’s and Kaiser–Meyer–Olkin (KMO) tests were used to determine the model’s significance.

3. Results

A total of 45 heat-vulnerable stops were identified in 32 census tracts. As a result of mapping 10 bus stops, each with the highest temperature at 6:00–7:00 a.m., 3:00–4:00 p.m., and 7:00–8:00 p.m., a total of 28 bus stops were identified. As a result of extracting the 10 bus stops with the highest HI each at 6:00–7:00 a.m., 3:00–4:00 p.m., and 7:00–8:00 p.m., 17 bus stops were identified (see Table S1).

3.1. Bus Stops with the Highest Temperature

The bus stops with the highest temperatures in the study area were centered around Kingston Pike and distributed in West Knoxville, Central Knoxville, and East Knoxville. The Kingston Pike is a major route connecting downtown Knoxville with West Knoxville and other municipalities in western Knox County and is an important commercial thoroughfare with hundreds of shopping malls, restaurants, and other retail outlets [46]. Results identified that the 10 bus stops with the highest temperature in the morning were distributed around West Town Mall, the largest shopping mall in Knoxville. Most bus stops with the highest temperatures in the afternoon and evening were in Central Knoxville and East Knoxville. Central Knoxville is home to downtown Knoxville and the University of Tennessee, which has the highest foot traffic in Knoxville. East Knoxville is home to 59.9% of the minority and 52.2% black population (see Figure 1).
The average temperatures of the bus stops identified as having the highest temperature were 23.7 °C in the morning, 34.0 °C in the afternoon, and 32.8 °C in the evening, which were 2.3 °C, 1.5 °C, and 1.7 °C higher than the average temperatures of all bus stops in Knoxville, respectively.

3.2. Bus Stops with the Highest Heat Index

Most of the bus stops with the highest HI in the study area were clustered in Central Knoxville (near the University of Tennessee, Knoxville, TN, USA) and the suburbs of Knoxville (North and South). The ten bus stops with the highest morning HI were in Fountain City and Smithwood, about five miles north of downtown Knoxville. These areas are recognized as underdeveloped areas with poor infrastructure, including bus stops. The ten bus stops with the highest HI in the afternoon were in Central Knoxville, and the ten bus stops with the highest HI in the evening were in the south suburb of Knoxville. This region’s rate for residents 65 and older and people with disabilities is about four percent higher than the average rate of Knox County (see Figure 2).
The average temperatures of the bus stops identified as having the highest HI were 40.6 °C in the morning, 40.1 °C in the afternoon, and 40.6 °C in the evening, which were 7.5 °C, 4.9 °C, and 7.5 °C higher than the average temperatures of all bus stops in Knoxville, respectively.

3.3. Land Cover Characteristics on Bus Stops

We mapped the 2019 NLCD data to examine the characteristics of the land surface in the area where the identified bus stops are located. The areas where most bus stops are located are developed with medium and high intensity, which means impermeable surfaces absorb and store heat (see Figure 3).
Of the 28 identified bus stops with the highest temperature, 14 are located in highly developed areas (NLCD class 24: impervious surfaces account for 80–100% of the total coverage, and apartment complexes, townhouses, and commercial/industry complexes where many people live or work are located). Thirteen bus stops are located in medium-intensity developed areas (class 23: impervious surfaces account for 50% to 79% of the total cover and areas with a mixture of constructed materials and vegetation; these areas most commonly include single-family housing units), and one bus stop is located in a low-intensity developed area (class 22: impervious surfaces account for 20–49% of the total coverage and commonly include a mixture of constructed materials like single-family housing units). Of the seventeen identified bus stops with the highest HI, five are located in highly developed areas (class 24). Six bus stops are located in medium-intensity developed areas (class 23), and five bus stop is located in low-intensity developed area (class 22). One bus stop is in a developed-open space (class 21: impervious surfaces account for less than 20% of the total coverage and commonly include a mixture of some constructed materials like single-family housing units but mostly vegetation in the form of lawn grasses such as parks, golf courses, and vegetation planted) [47].

3.4. Presence of Trees and Shelters

According to the result of the investigation of the presence of trees and shelters at the bus stops, 17 of the 28 bus stops with the highest temperature had no shelters or trees, one had only shelters, seven had only trees, and three had both shelters and trees. In addition, 16 of the 17 stops with the highest HI had no shelter or trees, and one had only shelter (see Figure 4).

3.5. SVI in the Areas Where the Most Heat-Vulnerable Bus Stops Are Located

For the social vulnerability, the PCA extracted two components that explained 67.19% of the variance in the data and had a KMO value of 0.685.
The first principal component of social vulnerability (PC1) exhibits a high positive correlation between the percentage of the Black/African American population estimate, minority estimate, households with no vehicle available estimate, people with no high school diploma (age 25+) estimate, unemployment rate estimate, explaining 35.23% of the variance in the data. The second principal component of social vulnerability (PC2) explains 31.96% of the variance in the data. It exhibits a high positive correlation between the percentage of people aged 17 and younger estimate, people aged 65 and older estimate, and civilian noninstitutionalized population with a disability estimate. The percentage of people in institutionalized group quarters and people below 150% poverty estimate were negatively correlated in PC2 (see Table 2).

4. Discussion

The results of the current study represent several key findings. First, as a result of the investigation of the bus stops’ temperatures, HI, and micro-environments, most heat-vulnerable bus stops are located in areas expected to be exposed to UHI and have poor micro-environments. Therefore, bus users may be exposed to heat when waiting for the bus, adversely affecting their thermal comfort.
The heat maps and 2019 NLCD data analysis showed that most of Knoxville’s heat-vulnerable bus stops are located in more highly developed and densely populated areas than the rest of Knoxville. These bus stops were found to be located in Kingston Pike, which is the busiest area in Knoxville, West Knoxville, which is the largest shopping complex is located, downtown Knoxville, which is home to the University of Tennessee, commercial districts, and government offices and Broadway, which connects downtown to North Knoxville. The characteristics of these regions are the areas where apartment complexes, housing complexes, and commercial and industrial complexes are located, and they have a minimum of 50% to a maximum of 100% impervious surface, making them vulnerable to the UHI effect. Bus stops with the highest HI were concentrated in the suburbs of Knoxville (North and South). Compared to other parts of Knoxville, these areas have been perceived as underdeveloped infrastructure, including bus stops. The HI at these bus stops was up to 7.5 °C higher than the average temperature in Knoxville, which was expected to affect thermal comfort for transit users adversely. Most bus stops were found to have no trees or shelters. Referring to studies showing that trees and shelters positively mitigate UHI effects [36], it may be necessary to modify bus stop microenvironments to address bus users’ health and safety.
Second, the patterns of social vulnerability in terms of socioeconomic status and racial and ethnic minority status were prominent in the identified areas. The cluster pattern of the Black/African American population estimate, minority estimate, households with no vehicle available estimate, people with no high school diploma (age 25+) estimate, and unemployment rate estimate was identified. In fact, the identified census tracts are those where poverty, unemployment, people with disability, households with no available car, minority, and black/African American population rates are above the Knoxville average. Knoxville’s southern, northeastern, and northwestern areas (census tracts 6800, 6700, and 7000) had 39.6, 29.9, and 27.7% of people without a vehicle, respectively, well above the Knoxville average (5.9%). Additionally, these areas’ minority percentage was the highest of any census tract, at about 60%. These areas had the highest proportion of the Black/African American population, with approximately half of the total population (53.8% in the South, 52.3% in the Northeast, and 41.5% in the Northwest) being Black/African American. Heat vulnerability is exacerbated for groups with low socioeconomic status and those living in UHI, and social vulnerability is associated with awareness, prevention, and response to hazards [48]. Accordingly, future studies may need to intersect the characteristics of at-risk populations to identify the context affected by UHI and establish a plan to expand education and communication on extreme heat.
This study, which identifies the microenvironment of heat-vulnerable bus stops and the patterns of social vulnerability where bus stops are located, has limitations, and these limitations can be an opportunity for future research based on our findings. First, the heat maps used in this study are not a perfect indicator of the heat experience of residents in a community. The experience of heat can be described by a number of factors, including the heat itself and the length of the extreme heat [49], and its impact on access to resources at the individual level [50]. We relied on heat maps from the 2022 Knoxville’s Heat Mapping Report and USGS’s 2019 NLCD land cover maps to determine which bus stops were vulnerable to heat, and there were limitations in acquiring and implementing knowledge of residents’ experiences using actual bus stops. However, as shown in other natural hazard studies, the availability of physical and social protective resources is related to the ability and vulnerability of individuals to respond to climate-related hazards [51,52,53]. Therefore, future research may need to focus on other aspects, such as residents’ perspectives on public transportation experience, response strategies and risk and protective factors in UHIs, and perceptions of sustainability and environmental protection.
Second, we understand that UHI is one of many environmental and social issues that impact Knoxville. Future studies may include variables that represent additional environmental-related factors, such as air quality indicators and associated diseases. Previous studies have shown that extreme heat frequently contributes to poor air quality. During a heat wave, extreme temperatures and stagnant air increase ozone and particle pollution levels, which may endanger residents’ health and safety [54]. Research incorporating environmental-related factors could help better explain that environmental injustice stems from more than one hazard [3].
Finally, this study investigated the land cover characteristics and the presence of trees and shelters as spatial characteristics of bus stops. However, many other micro-scale built environment features around public transit stops or stations can influence the relation of vulnerability to heat in public transit [33]. For example, Lanza et al. investigated the associations between various environmental features and ridership using 58 micro-scale transit infrastructure environmental indicators in six categories [33]. Future work may need to develop quantifiable metrics that include measurements of other environmental factors to identify bus stops with higher heat vulnerability and ridership.

5. Conclusions

To establish environmental justice-oriented climate adaptation policies and interventions, it is important for public transit agencies and future transit policies to take into account the effects of climate change and extreme heat on public transit riders and the corresponding risks involved. This case study in Knoxville, Tennessee, found that bus stops, which are most vulnerable to heat, were exposed to harsh microenvironments that may adversely affect the health and safety of public transport users. Most bus stops were found to lack trees and shelters and be in highly developed areas with impervious surfaces, making them vulnerable to UHI effects. The average temperature of the identified bus stops was up to 2.3 °C higher than the other bus stops in Knoxville, and the heat index was up to 7.5 °C higher. Identified bus stops were mostly concentrated in West Knoxville, South, North, Northeast, and Northwest Knoxville near the Northwest Knoxville, and Central Knoxville (near the University of Tennessee and downtown Knoxville). The identified areas were primarily home to systematically marginalized populations, dense commercial areas, and urban centers that could be exposed to significant UHI effects. By examining the identified bus stops at risk and the social vulnerability of the area, this study identified areas negatively impacted by UHI effects, providing foundation data for mitigation strategies that can better prepare cities to address community heat vulnerability within public transportation infrastructure.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/su151410866/s1, Table S1: SVI in the census tracts and adjacent census tracts where the most heat-vulnerable bus stops are located.

Author Contributions

Conceptualization, S.L. and J.M.F.; methodology, S.L.; writing—original draft preparation, S.L.; writing—review and editing, J.M.F. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data used to support the findings of this study are included within the article.

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. Bus stops with the highest temperature in the study area.
Figure 1. Bus stops with the highest temperature in the study area.
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Figure 2. Bus stops with the highest heat index in the study area.
Figure 2. Bus stops with the highest heat index in the study area.
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Figure 3. Land cover characteristics on bus stops with 2019 National Land Cover Data.
Figure 3. Land cover characteristics on bus stops with 2019 National Land Cover Data.
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Figure 4. The microenvironment of bus stops (shelter and tree).
Figure 4. The microenvironment of bus stops (shelter and tree).
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Table
Table 1. Analyzed variables of the 2018 Social Vulnerability Index.
Table 1. Analyzed variables of the 2018 Social Vulnerability Index.
Vulnerability AspectsDescriptionsVariable Names
Socioeconomic status% of people below 150% poverty estimateEP_POV
Unemployment rate estimateEP_UNEMP
% of people with no high school diploma (age 25+) estimateEP_NOHSDP
Household characteristics% of people aged 65 and older estimate, 2014–2018 American Community Survey (ACS)EP_AGE65
% of people aged 17 and younger estimate, 2014–2018 ACSEP_AGE17
% of civilian noninstitutionalized population with a disability estimate, 2014–2018 ACSEP_DISABL
Racial and ethnic minority status% of minority (all people except white, non-Hispanic) estimate, 2014–2018 ACSEP_MINRTY
% of Black/African American population estimateEP_AFAM
Housing and
transportation		% of households with no vehicle available estimateEP_NOVEH
% of people in institutionalized group quarters estimate, 2014–2018 ACSEP_GROUPQ
Table
Table 2. Component matrix of social vulnerability.
Table 2. Component matrix of social vulnerability.
Vulnerability
Aspects		Variable NamesPC1PC2The Number of Bus Stops in Census Tracts with Variable Scores below Knox County’s Average
Socioeconomic statusEP_POV0.609−0.70122
EP_UNEMP0.559−0.17424
EP_NOHSDP0.6770.33822
Household
characteristics		EP_AGE65−0.3300.79922
EP_AGE170.1830.82011
EP_DISABL0.3470.76428
Racial and ethnic minority statusEP_MINRTY0.8650.11724
EP_AFAM0.9260.10126
Housing and
transportation		EP_NOVEH0.711−0.26823
EP_GROUPQ0.082−0.75521
Eigenvalue3.6193.100
Proportion (%)35.22831.963
Culminative (%)35.22831.963
KMO test0.685 (p < 0.001)
Bartlett’s testTest value: 222.470, degrees of freedom: 45
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Lee, S.; First, J.M. Investigation of the Microenvironment, Land Cover Characteristics, and Social Vulnerability of Heat-Vulnerable Bus Stops in Knoxville, Tennessee. Sustainability 2023, 15, 10866. https://doi.org/10.3390/su151410866

AMA Style

Lee S, First JM. Investigation of the Microenvironment, Land Cover Characteristics, and Social Vulnerability of Heat-Vulnerable Bus Stops in Knoxville, Tennessee. Sustainability. 2023; 15(14):10866. https://doi.org/10.3390/su151410866

Chicago/Turabian Style

Lee, Sangwon, and Jennifer M. First. 2023. "Investigation of the Microenvironment, Land Cover Characteristics, and Social Vulnerability of Heat-Vulnerable Bus Stops in Knoxville, Tennessee" Sustainability 15, no. 14: 10866. https://doi.org/10.3390/su151410866

APA Style

Lee, S., & First, J. M. (2023). Investigation of the Microenvironment, Land Cover Characteristics, and Social Vulnerability of Heat-Vulnerable Bus Stops in Knoxville, Tennessee. Sustainability, 15(14), 10866. https://doi.org/10.3390/su151410866

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