The Influence of Urban Development Patterns on Streamflow Characteristics

The impervious surfaces, stormwater drainage systems, and compacted soils common throughout urban environments fundamentally alter streamflow characteristics. Cities are particularly vulnerable to damaging flooding events and altered low flow regimes that can have notable ecological implications. Although the general impacts of urbanization on streamflow are widely recognized, it is not entirely clear how the composition, position, and configuration of urban development influences both high and low flow regimes. The overarching research objective of this study is to clarify these relationships by quantifying the patterns of urban development in watersheds throughout major metropolitan areas in the United States via spatial metrics. Multivariate regression modelling is used to analyze the relationships between the urban development patterns and streamflow characteristics, which are derived using a partial duration series technique. Results will be presented for discussion and evaluation. A more precise understanding of how urban development patterns influence both high and low flow regimes should enable urban planners to advance beyond policies aimed at keeping imperviousness below a certain threshold and provide a basis for more detailed measures that could reduce the impacts of urbanization on hydrologic systems. Such progress appears imperative given that urban areas will likely be exposed to an increased frequency of extreme rainfall events and prolonged dry periods in the future due to climate change.