Water Resources Research Act Program

Details for Project ID 2008NC108B

Development of the Semi-Empirical Ammonia Deposition and Emission (SEADE) Model for Application to North Carolina Coastal Watersheds

Institute: North Carolina
Year Established: 2008 Start Date: 2008-03-01 End Date: 2010-02-28
Total Federal Funds: $26,004 Total Non-Federal Funds: $59,714

Principal Investigators: Wayne Robarge, Robert Austin, John Walker

Project Summary: In this proposal we present a new method for predicting ambient NH3 concentrations and bi-directional air-surface exchange at field to watershed scales in areas where animal production intensity is high. For development and initial testing, the model domain includes the Neuse and Cape Fear River basins in eastern North Carolina. This region of the state contains some of the highest county-scale NH3 emissions in the U.S. The model incorporates a facility-scale NH3 emissions inventory from which ground-level ambient NH3 concentrations are predicted as a nonlinear function of distance from the nearest source. Ammonia air-surface exchange rates are determined using a two-layer canopy compensation point model that takes into account differences in soil, vegetation, and water emission potential, as well as surface physical characteristics for primary land use categories. Model output includes NH3 emissions from agricultural point sources, atmospheric concentrations, and net air-surface exchange fluxes at 100 m resolution. This model is intended as a tool for estimating ammonia nitrogen deposition to terrestrial and aquatic ecosystems in agricultural areas. This information is critical to the development of watershed nutrient budgets and for assessing the impact of agricultural operations on ecosystem health and water quality. This research is directly relevant to WRRI Priority Research Areas C (Nutrients and Water Quality) and F (Agricultural Impacts).