Results

Abstract

Objectives

Methodology

Study Area

Earth Observations

Acknowledgements

Project Partners

Team Members

Phoe

nix

Heal

th &

Air

Qua

lity

II

Utilizing NASA Earth Observations and Ground Measurements to Reduce Extreme

Heat Experienced by Transit Riders in Phoenix, Arizona

Conclusions

City of Phoenix, Public Transit Department

Arizona State University, Urban Climate Research Center

Arizona State University, Center for Policy Informatics

Lance WatkinsProject Lead

Elizabeth Dyer Yalin Qu Dean Blumenfeld

Arizona – TempeFall 2017

Mario Chavez

Phoenix, Arizona, a city with 1.5 million residents, experiences extreme heat every year from May through October, with summer daily maximum temperatures regularly rising over 100°F, and a record high temperature of 122°F. Residents are prone to thermal discomfort during these summer months, especially those who rely on public transportation, making environmental heat a significant public health concern. The City of Phoenix Public Transit Department is heavily invested in addressing this concern through infrastructure development aimed at reducing riders’ heat exposure at bus stops. The Department’s previous method of determining priority for improvements such as shade structures, was based solely upon ridership. The NASA DEVELOP team provided the Transit Department with an analysis of the thermal environment at city bus stops, data which may be used when prioritizing the installation of new shade structures at unshaded stops. Land Surface Temperatures (LST) from Landsat 8 Operational Land Imager (OLI) and in situ LST and air temperature measurements were collected to provide a better understanding of the thermal environment at transit stops. LiDAR data was used to extract building heights in order to examine secondary shade potential within the thermal environment. We also created an assessment on the vulnerability of riders based on a selection of demographic and socioeconomic characteristics of the surrounding area. These results will contribute to the Phoenix Transit Department’s efforts to reduce the risk of heat-related illness for transit riders across the city and promote the viability of public transportation to achieve long-term health and sustainability goals.

4Provide partners with heat-related information

4Validate satellite LST by conducting site visits to sampled bus stops

4Assess vulnerability of residents using Census data

4Estimate secondary shade at and around bus stops

Landsat 8 OLI

Phoenix, AZ

DATA ANALYSISPROCESSING4Landsat 8 satellite

imagery4Ground in situ

Measurement Data

4Landsat 8 Based LST4Ground Measurement

Based LST4Ground Measurement

Based Air Temperature

4LST Validation

4LiDAR4NAIP Aerial

Imagery

4CENSUS ACS

4LiDAR Building and Walkway Layers

4NAIP Vegetation Prevalence Layer

4Census Social Vulnerability Layers

4Secondary Shade Analysis

4Heat Vulnerability Analysis

Bus Stop #

Tem

pera

ture

(F)

1127 9365 2630 4362 4334 2214 3672 6791 3860 6393 3851 315490.00

100.00

110.00

120.00

130.00

Land Surface Temperature Validation

Landsat LST Adjusted In-situ LST Insitu LST

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%1127 2214 2630 3154 3672 3851 3860 4334 4362 6393 6791 9365

Bus Stop #

Land Cover in Bus Stop Pixel

Asphalt Ground Vegetation Building Concrete Ground Bare Ground

NHDH NCDC

LiDAR

David Hondula, Joe Bowar, Herb Munoz, Jorie Bresnahan, Ariana Middel, David Sailor, Matthew Toro, Tamara Dunbarr, McKenzie Murphree, Mary Wright, Hana Putnam

4Landsat 8 Land Surface Temperature closely matches in situ LST of transit stops.

4Normal Difference Vegetation Index (NDVI) shows more vegetation equates to a lower LST.

4LiDAR preliminary results show secondary shading also lowers LST values, this topic should be explored more in future work.

Bus Stop #

10/5

/201

7 0:00

10/5

/201

7 1:00

10/5

/201

7 2:00

10/5

/201

7 3:00

10/5

/201

7 4:00

10/5

/201

7 5:00

10/5

/201

7 6:00

10/5

/201

7 7:00

10/5

/201

7 8:00

10/5

/201

7 9:00

10/5

/201

7 10:0

0

10/5

/201

7 11:0

0

10/5

/201

7 12:0

0

10/5

/201

7 13:0

0

10/5

/201

7 14:0

0

10/5

/201

7 15:0

0

10/5

/201

7 16:0

0

10/5

/201

7 17:0

0

10/5

/201

7 18:0

0

10/5

/201

7 19:0

0

10/5

/201

7 20:0

0

10/5

/201

7 21:0

0

10/5

/201

7 22:0

0

10/5

/201

7 23:0

0

372137273733373937453751375737633769377537813787379337993805381138173823382938353841384738533859386538713877388338893895390139073913391939253931393739433949395539613967397339793985399139974003400940154021402740334039404540514057406340694075408140874093409941054111411741234129413541414147415341594165417141774183418941954201420742134219422542314237424342494255426142674273427942854291429743034309431543214327433343394345435143574363436943754381438743934399440544114417442344294435444144474453445944654471447744834489449545014507451345194525453145374543454945554561456745734579458545914597460346094615462146274633463946454651465746634669467546814687469346994705471147174723472947354741474747534759476547714777478347894795480148074813481948254831483748434849485548614867487348794885489148974903490949154921492749334939494549514957496349694975498149874993499950055011501750235029503550415047505350595065507150775083508950955101510751135119512551315137514351495155

65

70

75

80

85

90

95

100

105

Bus Stop Air Temperature (°F)by HOBO on 2017/10/05

2360 3851 3860 2214 6791 3672 9365 4362 6393 3154