TRENDS IN THE CHEMISTRY OF ACIDIFIED BOHEMIAN LAKES FROM 1984 TO 1995- I - MAJOR SOLUTES

Citation
J. Vesely et al., TRENDS IN THE CHEMISTRY OF ACIDIFIED BOHEMIAN LAKES FROM 1984 TO 1995- I - MAJOR SOLUTES, Water, air and soil pollution, 108(1-2), 1998, pp. 107-127
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environmental Sciences","Water Resources","Metereology & Atmospheric Sciences
Journal title
ISSN journal
0049-6979
Volume
108
Issue
1-2
Year of publication
1998
Pages
107 - 127
Database
ISI
SICI code
0049-6979(1998)108:1-2<107:TITCOA>2.0.ZU;2-9
Abstract
Temporal changes in major solute concentrations in six Czech Republic lakes were monitored during the period 1984-1995. Four chronically-aci dic lakes had decreasing concentrations of strong-acid anions (C-SA = SO42- + NO3- + Cl-), at rates of 3.0 to 9.0 mu eq L-1 yr(-1). Decrease s in SO42-, NO3-, and Cl- (at rates up to 5.1 mu eq L-1 yr(-1), 3.2 mu eq L-1 yr(-1), and 0.6 mu eq L-1 yr(-1) respectively) occurred. The r esponse to the decrease in deposition of S was rapid and annual declin e of SO42- in lake water was directly proportional to SO42- concentrat ions in the acidified lakes. Changes in NO3- concentrations were modif ied by biological consumption within the lakes. The decline in C-SA wa s accompanied in the four most acidic lakes by decreases in Al-T, incr eases in pH at rates of 0.011 to 0.016 pH yr(-1), and decreases of Ca2 + and Mg2+ (but not Na+) in three lakes. The acid neutralizing capacit y (ANC) increased significantly in all six lakes. Increases in base ca tion concentrations (C-B = Ca2+ + Na+ + Mg2+ + K+) were the principal contributing factor to ANC increases in the two lakes with positive AN C, whereas decrease in CSA was the major factor in ANC increases in th e four chronically-acidic lakes. The continued chemical recovery of th ese lakes depends on the uncertain trends in N deposition, the cycling of N in the lakes and their catchments, and the magnitude of the futu re decrease in S deposition.