Quantifying hydrologic and land use controls on the timing and magnitude of watershed nitrogen export
Discharge, land use, and stormwater management have been found to be important determinants of nitrogen (N) export to receiving waters. We used long-term water quality stations from the Baltimore Ecosystem Study Long-Term Ecological Research (BES LTER) Site to assess the cumulative effect of stormwater control basins, green infrastructure, and stream restoration on nitrogen export at the watershed scale. We calculated nitrate and total nitrogen fluxes using methodology that enables accounting for watershed changes over time; weighted regressions on time, discharge, and seasonality. Here we tested the hypotheses that a) while the largest N stream fluxes occur during storm events, there is not a clear relationship between N flux and discharge and b) N export patterns are aseasonal in developed watersheds where sources are larger and retention capacity is lower. Developing a better understanding of hydrologic, seasonal, and long-term influences on nitrogen export is essential for successful adaptive watershed management.
Jon Duncan (Primary Presenter/Author), University of North Carolina at Chapel Hill, firstname.lastname@example.org;
LAWRENCE BAND ( Co-Presenter/Co-Author), UNC CHAPEL HILL, email@example.com;
Peter Groffman ( Co-Presenter/Co-Author), City University of New York, Peter.Groffman@asrc.cuny.edu ;