Scientific Investigations Report 2012–5035
Stream hydrology is foundational to aquatic ecosystems and has been shown to be a structuring element for fish and invertebrates. The relations among urbanization, hydraulics, and invertebrate communities were investigated by the U.S. Geological Survey, National Water-Quality Assessment Program by using measures of stream hydraulics in two areas of the United States. Specifically, the hypothesis that the effects of urbanization on streamflow and aquatic biota are transferable across geographic regions was tested. Data from sites in Raleigh, North Carolina, and Milwaukee–Green Bay, Wisconsin, were compared and indicate that increasing urbanization has an effect on hydraulic characteristics (Reynolds number, shear stress, and stream power for example) in each metropolitan area, though limited commonality of significant correlations was noted between areas. Correspondence of significant correlations between invertebrate and hydraulic metrics between study areas also was limited. The links between urbanization, hydraulics, and invertebrates could be seen only in the Raleigh data. Connections among these three elements in the Milwaukee–Green Bay data were not clear and likely were obscured by antecedent land cover. Observed biotic differences due to hydrology and urbanization characteristics are not similar between geographic regions.
First posted May 15, 2012
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Knight, R.R., and Cuffney, T.F., 2012, Invertebrate response to changes in streamflow hydraulics in two urban areas in the United States: U.S. Geological Survey Scientific Investigations Report 2012–5035, 19 p.
Site Selection and Description of Study Areas
Data-Collection and Analysis Methods
Stage and Streamflow Data
Invertebrate Data and Metrics
Invertebrate Responses to Urbanization and Hydraulics
Hydraulic Metrics and Urban Intensity
Hydraulic Metrics and Invertebrate Responses
Summary and Conclusions