Laudon, Hjalmar
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Research article2001Peer reviewed
Westling, Olle; Laudon, Hjalmar; Löfgren, Stefan; Bishop, Kevin
The natural preindustrial ANC and pH decline associated with 22 melt events from 11 streams during spring flood of 1997 and 1998 in Northern Sweden have been assessed using the Boreal Dilution Model (BDM). The results show that the spring flood pH decline of 0.5 to 2.5 pH units in the streams was largely caused by natural processes. The most important driving factors influencing pH were TOC increase in combination with ANC dilution. The study also demonstrates that pH in some streams can decline to pH values close to 4.5 as a result of natural processes alone. In general the anthropogenic component of the pH decline was between 0.1 and 0.3 pH units superimposed on the natural pH decline. Furthermore, the anthropogenic contribution to ANC and pH decline generally followed the gradient of anthropogenic S deposition in the region. The sites with the greatest inferred anthropogenic influence are also those for which the assumptions used in the BDM were most sensitive. Nevertheless, the results from this study suggest that the regional impact of anthropogenic acid deposition on the ANC and pH in northern Sweden is currently limited.
acid deposition; episodic acidification; natural acidity; surface water acidification; spring flood; Total Organic Carbon (TOC)
Biogeochemistry
2001, Volume: 54, number: 2, pages: 171-195
Lakes and watercourses
Forest
Acidification
Use of FOMA data
Environmental Sciences
Geochemistry
Oceanography, Hydrology, Water Resources
DOI: https://doi.org/10.1023/A:1010614631588
https://res.slu.se/id/publ/39219