Sponsor
Nohad A. Toulan School of Urban Studies and Planning
First Advisor
Vivek Shandas
Term of Graduation
Spring 2025
Date of Publication
6-3-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (Ph.D.) in Urban Studies
Department
Urban Studies and Planning
Language
English
Subjects
Urban temperature -- United States, Urban climatology -- United States, Sustainability, Urban forestry -- United States
DOI
10.15760/etd.3938
Physical Description
1 online resource (viii, 166 pages)
Abstract
This dissertation provides a comprehensive analysis of the interaction between urban heat and green infrastructure (GI) in terms of dynamic aspects, spatiotemporal variation across various spatial scales, temporal phases, and socioeconomic contexts. By integrating a national-scale longitudinal analysis, street-level structural assessments, and neighborhood-specific resilience frameworks, this study enhances our understanding of how cities can utilize existing ecological assets to mitigate increasing heat risks while addressing systemic inequities.
Urban areas face unprecedented thermal challenges due to climate change and the urban heat island effect, with marginalized communities disproportionately affected. Although cities are increasingly adopting GI expansion for heat mitigation, significant knowledge gaps remain regarding the spatiotemporal complexity of thermal dynamics and their socio-ecological implications. This research utilized a unique pedestrian-level air temperature dataset from the National Integrated Heat Health Information System (NIHHIS) Heat Watch Campaign to explore these dynamics through three interconnected studies.
The first study investigated decadal changes (2013/14-2022/23) in urban greenery across 33 U.S. cities, employing satellite-derived vegetation indices and high-resolution urban air temperature maps.
The second study, conducted across four mid-latitude cities (Portland, Washington D. C., Philadelphia, and Boston), integrates vehicle-collected air temperature data with municipal tree inventories to assess cooling performance.
The resilience framework for the Portland Metro area distinguishes between resistance (afternoon-evening cooling) and recovery phases (evening-morning cooling). Through clustering analysis, seven neighborhood typologies were identified, revealing phase-dependent effects of urban characteristics. Areas with 30% canopy coverage optimized both resilience phases, whereas those with coverage exceeding 40% hindered overnight cooling. Socioeconomic disparities were apparent, with lower-income areas experiencing elevated temperatures, and low recovery cooling was correlated with racial demographics. The resilience framework offers planners a tool to evaluate neighborhood thermal performance, such as the "cumulative heat exposure" introduced in the study, and to identify phase-specific intervention needs.
Rights
© 2025 YunJae Ock
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
https://archives.pdx.edu/ds/psu/43788
Recommended Citation
Ock, YunJae, "Dynamics of Urban Heat and Green Infrastructure" (2025). Dissertations and Theses. Paper 6817.
https://doi.org/10.15760/etd.3938