Abstract

By means of an atmospheric transport model estimates have been made of the total potential acid deposition in the Netherlands for the years 1980, 1985, 1994 and 2000. Spatial resolution of the calculation was 5 x 5 km2. Emission inventories appied for 1994 and 2000 are based on the emission reduction targets as formulated by the Dutch government in the Abatement Plan Acidification (Bestrijdingsplan Verzuring). For foreign emissions it is assumed that the maximal expected reductions will be realized. The calculations show that for the Netherlands on the average, deposition of total potential acid reduces from 6200 mol H+/ha/yr in 1980 to 3700 mol H+/ha/yr in 1994 and further to 2300 mol H+/ha/yr in 2000. If the assumptions with respect to emission reductions are correct, the deposition target which states that the acid deposition averaged over the Netherlands may not exceed 2400 mol H+/ha/yr, will be reached in the year 2000. Also the target for total nitrogen deposition (1600 mol N/ha/yr) and the interim deposition target formulated for the year 1994 (4000 mol H=/ha/yr) will be realized. Although the deposition decreases, in the year 2000 the deposition flux will exceed the critical value of 2400 mol H+/ha/yr in large parts of the Netherlands. The percentage of 5x5 km2 grid cells in which a potential acid deposition larger than 2400 mol H+/ha/yr has been calculated decreases from 98% in 1985 to 46% in 2000. The additional target value for total-N deposition (1600 mol N/ha/yr) is exceeded in 37% of the grid cells in 2000.