Journal of Conference Abstracts

MAGIC, SAFE and SMART Model Applications at Integrated Monitoring Sites: Effects of
Emission Reduction Scenarios

Martin Forsius¹ (martin.forsius@vyh.fi), Mattias Alveteg² (mattias.alveteg@chemeng.lth.se), Alan Jenkins³ (a.jenkins@unixa.nerc-wallingford.ac.uk), Matti Johansson¹ (matti.johansson@vyh.fi), Sirpa Kleemola¹ (sirpa.kleemola@vyh.fi), Anke Lükewille⁴ (anke.lukewille@niva.no), Maximilian Posch⁵ (max.posch@rivm.nl), Harald Sverdrup² (harald sverdrup@chemeng.lth.se) & Charlotta Walse² (charlotta.walse@chemeng.lth.se)

¹ Finnish Environment Institute, P.O. Box 140, FIN-00251 Helsinki, Finland.

² Lund University, Chemical Engineering II, P.O.Box 124, S-22 100 Lund, Sweden.

³ Institute of Hydrology, Wallingford, OXON, Oxfordshire OX10 8BB, U.K.

⁴ Norwegian Institute for Water Research, P.O.Box 173 Kjelsås, N-0411 Oslo, Norway.

⁵ RIVM, P.O.Box 1, NL-3720 BA Bilthoven, The Netherlands.

Three well-known dynamic acidification models, MAGIC, SAFE and SMART, were applied to a consistent data set from five Integrated Monitoring sites in Europe. The Integrated Monitoring Programme (ICP IM) is part of the effects monitoring strategy under the Convention on Long-Range Transboundary Air Pollution (LRTAP) of the United Nation's Economic Commission for Europe (UN/ECE). The calibrated models were used to predict the long-term acidification of soils and runoff water of these background forested catchments, given different scenarios of future deposition of sulphur and nitrogen (target year 2050). These scenarios were based on agreed measures for emission reductions.

Site specific deposition and nutrient uptake scenarios, combining both measured and modeled information, were derived for each IM-site. These deposition and uptake patterns were used to drive the models and produce the chemical changes in soil and stream water chemistry over time. The models were calibrated to produce present day (1990-94) soil and stream water chemistry. The three models yielded generally consistent results, which gives confidence in the scenario assessment. The 'Best Prediction' scenario, including the effects of the second UN/ECE protocol for reductions of SO₂ emissions and present level for NO_x-emissions, resulted in many cases in a stabilisation in the soil acidification, although significant improvements were not always shown. With the exception of one site, the 'Maximum Feasible Reductions' scenario always resulted in significant improvements.

The model's simulations showed that catchments respond in a dynamic way to changes in emissions/deposition. The time development of acidification is important also for determining necessary measures for emission control. Site-specific dynamic model applications are therefore needed as a complement to steady-state techniques for mapping of so called critical loads, where adequate data are available. The steady-state critical load concept, presently, is used extensively for policy negotiations carried out under the framework of the LRTAP Convention.