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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #341870

Research Project: Mitigating Emissions and Adapting Farm Systems to Climate Variability

Location: Pasture Systems & Watershed Management Research

Title: Assessing the impacts of climate change on discharge and nutrient losses from a karstic agricultural sub-basin in the Upper Chesapeake Bay watershed

Author
item Gunn, Kpoti (stephan)
item Veith, Tameria - Tamie
item Buda, Anthony
item Amin, Mostofa - Pennsylvania State University
item Rotz, Clarence - Al
item Hayhoe, Katherine - Texas Tech University

Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2017
Publication Date: 6/25/2017
Citation: Gunn, K.M., Veith, T.L., Buda, A.R., Amin, M., Rotz, C.A., Hayhoe, K. 2017. Assessing the impacts of climate change on discharge and nutrient losses from a karstic agricultural sub-basin in the Upper Chesapeake Bay watershed. In: Book of abstracts, pg 136. International Soil and Water Assessment Tool Conference, Warsaw University of Life Sciences, Warsaw Poland, June 28-30. Blackland Research Station, Texas.

Interpretive Summary: No Interpretive Summary is required for this Abstract. JLB.

Technical Abstract: The health of the Chesapeake Bay Basin ecosystem, which lies within the heavily populated Northeastern United States, relies on reducing nutrient loading to the Chesapeake Bay by the 2025 TMDL deadline and on into the future. Doing so requires evaluating the impact of current agricultural management practices within the Basin and determining how these practices may need to evolve in response to climate change. Numerous modeling efforts have explored the efficiency of proposed best management practices that can be implemented to reach that goal. However, the karstic geological nature and variable source area (VSA) hydrology of the Valley and Ridge physiographic province within the Upper Chesapeake Bay represent particularly interesting hydrogeologic challenges in such modeling. Spring Creek Watershed, a representative agricultural sub-basin with karst geology and VSA hydrology within the Chesapeake Bay watershed in south central Pennsylvania, is 34% agriculture, 23% developed, and 43% forested. We used the Spring Creek Watershed realization of Topo-SWAT, a version of SWAT that incorporates variable source area hydrology, to investigate the discharge and nutrient losses from the watershed in 2015, 2025, 2050, and 2075 under current and projected climate conditions and current land use and land management practices. The climate projections were generated from nine coupled Model Intercomparison Project Phase 5 (CMIP5) models run under both high and intermediate emission scenarios and downscaled to point locations in the northeastern United States. Preliminary analyses of the climate projections show sharp increases in annual and, especially, fall and winter total precipitation plus narrowing mean annual diurnal temperature ranges in the Spring Creek watershed over the 21st century. Results from Topo-SWAT will characterize the variability of potential watershed responses to the different climate forcings. An examination of these potential climate change impacts on nutrient loads discharged at the watershed outlet and the associated agricultural management practices will be used in future work to guide development of a focused restoration strategy for this and similar watersheds within the Chesapeake Bay Basin.