Base cation deposition in europe-part I. 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 inferential modeling technique. Deposition fields resembled the geographic variability of sources, land-use and climate. Dry deposition constituted on average 45% of the total base cation deposition in Europe. Modeled deposition estimates compared reasonably well with deposition estimates 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 cell of 10 x 20 km was estimated to equal 35–50% and 25–40%, respectively. Within individual grids a relatively large variability in deposition is expected.