Associations between sociodemographics and green infrastructure placement in Portland, Oregon

Past research has shown that green space may not be equitably distributed throughout urban areas based on socioeconomic status. This study assessed correlations between sociodemographic factors and green stormwater infrastructure placement, specifically green streets and green roofs, in Portland, Oregon. Green stormwater infrastructure density and sociodemographic factors were compiled at the scale of U.S. Census block groups. Socioeconomic factors examined were income, age, minority percentage, and education level achieved. Significant correlations using all block groups indicated higher green street densities in areas with lower median income, lower median age, higher percentage of minority groups, and fewer people with a bachelor's degree. Examining only block groups that included a stormwater facility, areas with lower median income and lower median age had higher densities of green roofs. These relationships suggest that installing green stormwater infrastructure in Portland may contribute to additional social and economic benefits given its placement throughout the city.