It is well documented that urbanized areas have been expanding worldwide, with urban sprawl in the United States booming since the mid twentieth century. One of the most geomorphologically significant aspects of this urbanization is the increase in impervious surfaces and the subsequent reduction in infiltration of precipitation. Lots of studies have been conducted on fluvial systems within urbanized areas, finding that lag time peak precipitation and stream discharge can drop by as much as 70% (Espey et al., 1965). Although the Chicago-Naperville-Elgin is already the third largest metropolitan statistical area in the nation (US Census Bureau), its built environment is still increasing on the periphery, which could potentially alter the existing streams and rivers of the area. The goal of this poster is to use the three northernmost counties of the Chicago-Naperville-Elgin MSA to compare the change in land use during the twenty-first century with the peak precipitation and discharge lag time. Through utilization of USGS stream gauges and NWS precipitation data, precipitation events of similar magnitude can be compared while factoring in the proximity to recently built up land. It is pertinent to understand the continually changing influence of urbanization on fluvial systems, even in areas that have traditionally already been considered urbanized.
Peak Discharge Lag Time in Urbanizing Streams of Northern Illinois