CLIMATE IMPACTS ON NUTRIENT FLUXES IN STREAM FLOW IN THE MID-ATLANTIC REGION

• Main Authors: B Yarnal, R Neff, J Allard, H Walker
• Format: Text
• Language: unknown
• Published: 2005
• Subjects: Mara; Soi; North Atlantic; North Atlantic oscillation
• Online Access: http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=80179

As part of a national assessment process, researchers of the Mid-Atlantic Regional Assessment (MARA) are studying the impacts of climate variation and change on the natural and social systems of the Mid-Atlantic Region. This poster presents research investigating climate impacts on the hydrology of the region, focusing on streamflow controls on water chemistry. Several methods were used, including spectral analysis and statistical and process-based hydrologic models. Nutrient fluxes in streamflow to coastal systems change not only because of changes in anthropogenic activity such as fertilization, release of wastewater, and atmospheric deposition of airborne pollution, but also because of climate variation. Spectral analysis showed significant periodic fluctuations in stream flow on interannual time scales that are associated with Southern Oscillation Index (SOI), the North Atlantic Oscillation (NAO), and solar variability. The statistical and process-based hydrologic models were calibrated and validated using historical data. The models then estimated future conditions using downscaled general circulation model (GCM) projections. The results suggest that streamflow in the Mid-Atlantic Region is sensitive to climate change. These results suggest that the projected increases in stream flow resulting from climate change could make it more difficult to reduce nitrogen and phosphorus fluxes to the coast and adversely affect anoxic volume in the Chesapeake Bay and therefore to the bay.