Spatial Interactions of Societal and Biophysical Attributes of Urbanizing Watersheds

Law, N L, and L.E. Band, University of North Carolina, Department of Geography, Saunders Hall, CB#3220, Chapel Hill, NC 27599 United States

The increased dominance of human systems in urbanizing watersheds actively modifies the magnitude, flowpaths and chemical signature of surface water. The natural drainage system is modified and supplemented through infrastructure (i.e. water supply and drainage) and sources are augmented by peoples' activities. The hydrologic impact of urbanization is well documented and includes higher peak flows commensurate with a decrease in baseflow, in addition to water quality degradation. However, research to explain human-environment interactions that affect the mass balance of water and nutrients in urban watersheds is limited. It is suggested that development patterns and human use of resources are key to conceptualizing the relationship between natural and human systems. For example, is there a predictable response in vegetation cover based on the spatial distribution of socio-economic characteristics within an urban watershed? Further, what is the relationship between the change in forested and agricultural land use to residential development and surface water quality? A statistical analysis of a multivariate dataset is used to identify socio-economic patterns of development from land use and census variables to predict the distribution of hydro-ecological variables. The quantification of the structural relationship amongst these variables can be used to parameterize hydro-ecological models for applications in urban ecosystems.