ABSTRACT
The sensitivity to acidification of surface waters in a region is a function of regional deposition characteristics, surface water chemistry, and watershed factors. This chapter attempts to integrate these three elements to provide a qualitative assessment of watershed sensitivity to acidification and a quantitative assessment of the magnitude of acidification experienced within the study regions. For the regions of the US identified as having sensitive aquatic resources, some relevant information has been compiled and evaluated subsequent to the National Acid Precipitation Assessment Program Integrated Assessment regarding the relationship between deposition loadings and the estimated extent, magnitude, and timing of aquatic effects. The total concentration of the mineral acid anions in surface waters that are derived from atmospheric deposition of air pollutants has changed over time throughout the northeastern US The sensitivity to acidification of surface waters in a region is a function of regional deposition characteristics, surface water chemistry, and watershed factors.
