Examining Urban Watershed Resilience In Cities And Gardens: A Spatial Analysis Of Equity Of Green Stormwater Infrastructure Distribution And A Mixed Methods Analysis Of Soil Properties And Sub-Surface Nutrient Leaching From Urban Gardens, In Light Of Gardener Perceptions And Management Practices

Abstract

Due to the expansion of urban development and land use, impervious surface area coverage has steadily increased across the United States. As urbanization occurs, the expansion of impervious area reduces watershed infiltration capacity, and increases flood events and water pollution via runoff. The heightened intensity of storm events due to climate change exacerbates this urban flood risk, particularly in vulnerable communities that lack adequate infrastructure to manage these challenges. The first chapter of this thesis introduces issues of urbanization, stormwater management, green stormwater infrastructure and connections between watersheds and urban agroecosystems. It also examines how systemic racism, both past and present, has led to Black people living in urban areas that are disproportionately vulnerable to flooding, deprived of climate resiliency measures, and often lacking in access to crucial food system components such as grocery stores. The second chapter explores the equitability of green stormwater infrastructure (GSI) distribution in the US cities of Washington D.C. and Milwaukee, Wisconsin. Through spatial and statistical analyses, the relationship between GSI implementation and the sociodemographic variables of percent Black population and median household income are examined in both cities. This research provides additional context to the existing body of literature addressing sociodemographic equity in green infrastructure distribution across US cities and considers “green gentrification” as a factor related to GSI implementation. The third chapter considers aspects of urban agroecosystems that relate to water quality using both natural science and social science methods. Urban gardens provide myriad benefits in social sustainability, particularly bolstering food sovereignty, but the extent to which they contribute to water pollution via nutrient leaching is underexplored. In this study, soil and water samples were collected from residential and community gardeners across urban and peri-urban sites in Chittenden County (Vermont, USA), to investigate the degree to which urban gardens leach soluble reactive phosphorus and nitrate into groundwater. Interviews were conducted with the gardeners to gain insight into their garden management practices and environmental awareness, revealing potential relationships between soil amendment usage and the extent of nutrient leaching within each garden. Through this analysis we gain insight into the potential of urban gardens as not just a means of food production, but as green infrastructure in a hydrological context