SOIL SENSITIVITY DUE TO ACID AND HEAVY-METAL DEPOSITION IN EAST-CENTRAL-EUROPE

Simultaneous soil acidification and deposition of heavy metals is a ma jor concern for forest and agricultural soils of the Black Triangle re gion of East Central Europe including southern former East Germany, no rthern Bohemia of the Czech Republic, and southern Poland. The objecti ve of this project was to develop historical and future projections of acid and heavy metal deposition to soils (As, Cd, Pb, Zn) and to prod uce a preliminary map of soil sensitivity to cadmium pollution and upt ake by crops. Ultimately, we wish to assess the relative hazard and re covery times of soils to metals deposition in the region. Emission and deposition data bases obtained from several models developed at IIASA were linked using the Geographical Information System ARC/INFO to pro duce soil maps of sensitivity to cadmium mobility based on metals depo sition, soil type, soil texture, organic matter content and acid depos ition. RAINS 6.1 (Alcamo et al., 1990) was utilized to produce maps of acid deposition for EMEP grids (150 km x 150 km). The largest amount of acid load is deposited in southern East Germany. Sulfur deposition in that area was 10-12 gS/m(2)/yr in 1990, and S+N deposition exceeded 8000 eq/ha/yr. But the ''hot spot'' for metals deposition is further to the east, in the Silesia area of southern Poland. The TRACE:! traje ctory model of Alcamo, Bartnicki, and Olendrzynski (1992) was used to estimate cumulative metals deposition since 1955 with scenarios to 201 0. Pb has improved over Europe since 1970 when depositions in the Ruhr River Valley of West Germany exceeded 60 mg/m(2)/yr. But cadmium depo sition in southern Poland (Katowice and Krakow) has now accumulated to 60-70 mg/m(2) by atmospheric deposition alone. During base case simul ations from 1955-87, approximately 1.8 mg/kg Pb and 0.12 mg/kg Cd have been added to the mixed plow-layer of similar to 30 cm. If these emis sions continue indefinitely, the accumulation of metals will become pr oblematic for agriculture and the food chain.