The Wisconsin Regional Integrated Lake-Watershed Acidification Study (RILWAS):1981-1983

摘要

Precipitation was 5 to 15 percent less than normal during the first year and 7 to 15 percent greater than normal during the second year. Snowfall accounted for 24 to 34 percent of the precipitation;however, all snowmelt infiltrated the highly permeable soils, and no spring depression in lake pH was observed. Chemistry of the precipitation was dominated by hydrogen ion, ammonium, and sulfate. Volume-weighted mean pH of bulk precipitation was 4.6 at both sites during the study, with hydrogen ion and ammonium contributing about 60 percent of the cations. Sulfate accounted for approximately 60 percent of the anions, annual sulfate fluxes ranged from 300 to 329 eq/ha. Dry deposition provided 7 to 36 percent of the total (wet plus dry) ion fluxes, except for magnesium (53 percent). Ion fluxes to the two lakes were similar.