Adirondack headwater lake chemistry relationships with watershed characteristics

Abstract

The Adirondack Region of New York State has been identified as having surface waters sensitive to acidic deposition and as receiving large annual inputs of acidic deposition. The large amount of data available for this region makes a quantitative study of the region possible. Compiled from a variety of sources, the Adirondack Watershed Data Base (AWDB) contains information on lake chemistry; lake elevation, area, and volume; and associated watershed data, such as size, slope, aspect, elevation, vegetation and wetland types, beaver activity, fire and logging history, and soils data. Bivariate and multivariate procedures were used to examine relationships between watershed attributes and lake chemistry. Because the variables in the data base are being refined and modified, the current relationships should be considered preliminary. Preliminary results indicate that wet deposition, lake elevation, and forest cover are the principal variables that are associated with variance in the data for lake pH and acid neutralizing capacity (ANC) in the Adirondacks. For headwater lakes in the Adirondacks, we estimate approximately 50% have a total ANC ≤ 40 μeq L−1 and 40% have a pH ≤ 5.5.