Modeling long-term streamwater chemistry in the Berg catchment, southwestern Sweden - Paper presented at the Nordic Hydrological Conference (Uppsala,Sweden June, 2000)

The geochemical model MAGIC (5.01) was applied to the Berg - Pipbacken Nedr e catchment in southwestern Sweden for the period 1846-2020. The major obje ctive was to reconstruct historical acidification trends and predict the su rface water and soil response to declining atmospheric deposition in the fu ture based on the Gothenburg Protocol signed in 1999. Another task was to t est the usefulness of Sweden's long-term small catchment monitoring program for a validation of the long-term acidification model. Berg has been one o f fifteen catchments monitored very intensively by the Swedish Environmenta l Protection Agency during 1986-1993 and less intensively later by the Swed ish University of Agricultural Sciences Department of Environmental Assessm ent. Anthropogenic atmospheric deposition was the dominant factor causing a decline of streamwater pH and especially soil base saturation. A scenario of future atmospheric deposition based on the emission reductions of S and N compounds agreed under the 1999 Gothenburg Protocol to the UNECE CLRTAP w as modeled. This scenario stopped further acidification of soils, but recov ery of streamwater pH and soil base saturation was slow and limited. Withou t further reductions from the deposition levels in 1995-1997, soil acidific ation would continue.