Evaluation of the Level of Acidification and the Critical Loads for Alpine Lakes
Marchetto A, Mosello R, Psenner R, Barbieri A, Bendett G, Tait D, Tartari GA. 1994. Evaluation of the Level of Acidification and the Critical Loads for Alpine Lakes. Ambio. 23(2):150-154
During 1988-1991, 413 high-mountain lakes in the Central Alps (Italy, Switzerland and Austria) were studied to quantify the influence of acid deposition. About two thirds of the lakes had alkalinity values of less than 200 µeq L-1 and were regarded as possibly sensitive to acidification. Moreover, 36% of the lakes showed alkalinity values of less than 50 µeq L-1 and 25% of the lakes lying in watersheds exclusively formed by acidic rocks had alkalinity below 20 µeq L-1. A titration model was used to evaluate losses in alkalinity (acidification levels) and to evaluate critical acid deposition, i.e. critical loads, for sensitive lakes. The results suggest that some lakes are so sensitive that any acid load would lead to alkalinity lower than 20 µeq L-1, at which value sensitive organisms are at risk. The applied model suggests that 20% reductions in acid deposition would result in safe conditions (= alkalinity levels above 20 µeq L-1) for 80% of the lakes lying in watersheds exclusively formed of acidic rocks. In the case of a 50% reduction, 75% to 88% of the lakes would reach the critical alkalinity value, depending on whether the reduction was in nitrate or sulfate, respectively.
- Type
- Journal Article
- Authors
- Marchetto, Aldo; Mosello, Rosario; Psenner, Roland; Barbieri, Alberto; Bendett, Gunther; Tait, Danilo; Tartari, Gabriele
- Units
- ARD
- Keywords
- Acid Deposition, Acidification, AIRBIB, alpine lakes, Watersheds