Nitrogen Bounding Study: Methods for Estimating the Relative Effects of Sulfurand Nitrogen Deposition on Surface Water Chemistry

摘要

The leaching of atmospherically deposited nitrogen from forested watersheds mayacidify lakes and streams. The Nitrogen Bounding Study evaluates the potential range of such adverse effects. The study estimates bounds on changes in regional-scale surface water acidification that might occur over the next 50 years across a broad range of scenarios of nitrogen and sulfur deposition and times to watershed nitrogen saturation. Computer simulations using a modified version of the Model of Acidification of Groundwater in Catchments were performed for 36 lake catchments in the Adirondack Mountains of New York, 29 stream catchments in the Mid-Appalachian Plateau, and 30 stream catchments in the Southern Blue Ridge Mountains. For each of the three regions and each scenario, the simulation modeling provided projections of the percentage of a specified target population of lakes or streams that could be chronically affected. The report documents the methods and assumptions of the study and presents tables and graphs of results.