R/E-24A

Strategic focus area:

Description:

Projected increases in intense precipitation events have the potential to alter the amount, source, and timing of stream nitrogen export and associated ecosystem impacts to the Chesapeake Bay. But, relatively little is known regarding amounts and sources of nitrogen exported during precipitation events and possible controls, such as hydrologic flowpaths and land use. The proposed research aims to quantify the amounts and sources of nitrogen along with dominant hydrologic flowpaths both within and among precipitation events in two tributaries of the Chesapeake Bay (one primarily urban and one primarily a mix of forest and agriculture). Isotopes of nitrate and water in stormwater stream samples will be measured to quantify nitrate sources and dominant hydrologic flowpaths, respectively. Relationships between nitrate amounts and sources will be analyzed in relation to dominant hydrologic flowpaths and land use to better understand drivers of storm nitrate export variability. Enhanced understanding of nitrogen export during storm events is critical for effective mitigation strategies and continued recovery of the Chesapeake Bay.