366 - Urban Rainfall Flood Risk Equity in Southeast Michigan

Extreme flood events are increasing in frequency and severity in many urban communities throughout the United States. It is becoming increasingly recognized that new approaches are needed to manage urban stormwater effectively, efficiently, and equitably. Increased housing density, impervious area, and changes in urban vegetation are barriers to natural stormwater management. Aging and insufficient infrastructure and disinvestment increase the economic and health risks associated with urban flooding, while socioeconomic disparities can lead to lack of resilience within urban communities. For example, disadvantaged populations are often less prepared for flooding events and less able to recover from flood damage, including the removal of water and sewage that can lead to health and safety threats. Understanding issues surrounding equity and environmental justice is an important aspect of stormwater management and planning. The objective of this study is to estimate rainfall flood risk in urban watersheds using high-resolution topography and land cover data, including green space, wetlands, and impervious surface area. Watershed sub-basins will be delineated for urban areas in southeast Michigan using high-resolution DEMs. Drainage areas for each sub-basin will be used to estimate surface runoff for each sub-basin by applying the NRCS runoff curve number and modified rational methods. Socioeconomic characteristics from the US Census American Community Survey will be added to provide important information on flood risk equity. Detroit, MI, will be used as a case study for mapping urban flood risks and social vulnerability. The results of this analysis will be useful for stormwater management planning and prioritizing areas for flood mitigation efforts in socioeconomically vulnerable urban areas.