Assessing Urban Green Space Effectiveness in Community Health Improvement in Portland

Thesis Abstract

Urban green spaces are increasingly recognized as vital components of sustainable city planning due to their potential to enhance community health outcomes; however, the extent of their effectiveness remains inadequately understood, particularly within the context of Portland’s diverse neighborhoods. This study aims to evaluate the effectiveness of urban green spaces in improving community health in Portland, identifying the key factors that influence health benefits and assessing spatial and socio-economic disparities in access and utilization. The specific objectives include measuring the impact of green space proximity and quality on physical activity levels, mental well-being, and social cohesion; examining neighborhood socio-economic variables that may mediate or moderate these relationships; and providing policy recommendations for equitable green space distribution. The research adopts a mixed-methods design, integrating quantitative spatial analysis and survey data with qualitative interviews to gain a comprehensive understanding of green space utilization and health outcomes. The population comprises adult residents of Portland living within 500 meters of designated urban green spaces, totaling approximately 5,000 individuals. A stratified random sampling technique is employed to select a sample of 600 participants proportional to neighborhood socio-economic strata. Quantitative data are collected through structured questionnaires measuring physical activity (using the International Physical Activity Questionnaire), mental health status (via the General Health Questionnaire), and social cohesion (using the Social Cohesion and Trust Scale). Geographic Information System (GIS) techniques are used to map green space proximity and quality indicators, such as size, safety, and amenities. Qualitative data are gathered through semi-structured interviews with 30 community leaders and urban planners, focusing on perceived green space benefits and barriers to utilization. Data analysis involves multiple statistical techniques, including multiple regression analysis to determine the associations between green space variables and health outcomes, and analysis of variance (ANOVA) to compare differences across socio-economic groups. Spatial analysis using GIS assesses variations in green space accessibility and their correlation with health indicators. Thematic analysis is employed for qualitative interview transcripts to contextualize quantitative findings and explore community perceptions. Expected findings anticipate a positive association between green space accessibility and improvements in physical activity, mental well-being, and social cohesion, with notable disparities linked to socio-economic status and neighborhood characteristics. The study also expects to identify specific green space attributes—such as safety, diversity of amenities, and maintenance—as critical for promoting utilization and health benefits. These results will contribute to the body of knowledge by providing empirical evidence linking green space quality and accessibility to diverse health metrics within an urban American setting, guided by the theoretical frameworks of the Ecological Model of Health and the Urban Green Space Benefits Theory. The study's main conclusion emphasizes that equitable access to well-maintained, high-quality green spaces significantly enhances community health in Portland, though disparities remain a challenge. Policy implications include prioritizing green infrastructure investments in underserved neighborhoods and incorporating community-driven design approaches. Recommendations advocate for integrating green space planning within broader urban health strategies, fostering cross-sector collaboration, and conducting ongoing monitoring utilizing spatial and health data. The research advances understanding of the spatial-health nexus in urban settings, providing a model for other cities seeking to leverage green spaces for health promotion. Future studies are suggested to explore longitudinal impacts, broader environmental benefits, and the role of cultural preferences in green space utilization.