Measuring the Fluxes of Suspended Sediment, Trace Elements and Nutrients for the City of Atlanta, USA: Insights on the Global Water Quality Impacts of Increasing Urbanization

During 2004 and 2005, suspended sediment fluxes from the City of Atlanta amounted to about 150,000 t year⁻¹; ≥ 94% of the transport occurred in conjunction with stormflow, which also accounted for ≥ 65% of the annual discharge; typically, stormflow occurred during ≤ 20% of the year. Based on annual median chemical concentrations for baseflow and stormflow, the annual fluxes of ≥ 75% of trace elements (e.g. Cu, Pb, Zn), major elements (e.g. Fe, Al) and total P were sediment-associated; in turn, ≥ 90% of this transport was storm-related. As such, baseflow sediment-associated and all dissolved contributions represent a relatively insignficant portion of the total annual load. An exception is total N, whose sediment-associated fluxes range from 50 to 60%; even so, storm-related transport exceeded 80% of the total.