MAGIC, SAFE AND SMART MODEL APPLICATIONS AT INTEGRATED MONITORING SITES - EFFECTS OF EMISSION REDUCTION SCENARIOS

Three well-known dynamic acidification models (MAGIC, SAFE, SMART) wer e applied to data sets from five Integrated Monitoring sites in Europe . The calibrated models were used in a policy-oriented framework to pr edict the long-term soil acidification of these background forest site s, given different scenarios of future deposition of S and N. Emphasis was put on deriving realistic site-specific scenarios for the model a pplications. The deposition was calculated with EMEP transfer matrices and official emissions for the target years 2000, 2005 and 2010. The alternatives for S deposition were current reduction plans and maximum feasible reductions. For N, the NOx and NHy depositions were frozen a t the present level. For NOx, a reduction scenario of flat 30 % reduct ion from present deposition also was utilized to demonstrate the possi ble effects of such a measure. The three models yielded generally cons istent results. The 'Best prediction'-scenario (including the effects of the second UN/ECE protocol for reductions of SO2 emissions and pres ent level for NOx-emissions), resulted in many cases in a stabilizatio n of soil acidification, although significant improvements were not al ways shown. With the exception of one site, the 'Maximum Feasible Redu ctions' scenario always resulted in significant improvements. Dynamic models are needed as a complement to steady-state techniques for estim ating critical loads and assessing emission reduction policies, where adequate data are available.