BASE CATION DEPOSITION IN EUROPE .1. MODEL DESCRIPTION, RESULTS AND UNCERTAINTIES

Deposition of base cations (Na+, Mg2+, Ca2+, K+) in Europe was mapped for 1989 with a spatial resolution of 10 x 20 km using the so-called i nferential modeling technique. Deposition fields resembled the geograp hic variability of sources, land-use and climate. Dry deposition const ituted on average 45% of the total base cation deposition in Europe. M odeled deposition estimates compared reasonably well with deposition e stimates derived from throughfall and bulk-precipitation measurements made at 174 sites scattered over Europe. Using error propagation, the random and systematic error in total deposition for an average grid ce ll of 10 x 20 km was estimated to equal 35-50% and 25-40%, respectivel y. Within individual grids a relatively large variability in depositio n is expected. (C) 1997 Elsevier Science Ltd.