Trends in Sulfate, Base Cations and H+ Concentrations in Bulk Precipitation and Throughfall at Integrated Monitoring Sites in Finland 1989-1995

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• 作者：Liisa Ukonmaanaho ; Michael Starr and Tuija Ruoho-Airola
• 关键词：base cations ; bulk precipitation chemistry ; catchments ; protons ; sulfate ; throughfall chemistry
• 刊名：Water, Air, and Soil Pollution
• 出版年：1998
• 出版时间：1998
• 年：1998
• 卷：105
• 期：1/2
• 页码：353-363
• 全文大小：524 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Atmospheric Protection, Air Quality Control and Air Pollution
  Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
  Terrestrial Pollution
  Hydrogeology
  
• 出版者：Springer Netherlands
• ISSN：1573-2932

文摘

Temporal trends in sulfate, base cation (Ca2+ + Mg2+ + K+), and H+ ion concentrations in bulk precipitation and throughfall samples collected over a seven year period (1989-95) in four forested catchments in Finland are presented. The catchments are in remote locations and span the boreal zone (61-69 °N). The stands represent old, undisturbed forests, and are composed of varying proportions of Scots pine, Norway spruce and deciduous species (mainly Betula spp.). Monthly SO₄2- and H+ ion concentrations in bulk precipitation averaged over the study period and catchments were: 18.7 µmol L-1 and 32.3 µmol L-1. The corresponding values for throughfall were: 37.4 µmol L-1 and 32.4 µmol L-1. Sulfate and H+ ion concentrations in bulk precipitation and throughfall both showed negative linear trends, which were significant (p ₄2- slope estimates: -1.6 to -1.0 µmol L-1 yr-1). The decline was greater for throughfall than for bulk precipitation, indicating a proportionally greater reduction in dry deposition than wet. The sum of base cation concentrations averaged 12.1 µmol(+) L-1 in bulk precipitation and 83.1 µmol(+) L-1 in throughfall. There were no significant trends in the sum of base cations (p > 0.05). It is concluded that the reported reduction in S emissions over the study period has resulted in a significant reduction in the acidity and SO₄2- concentration of bulk precipitation, and this reduction has has been reflected in throughfall concentrations. The greatest reduction has taken place in the southern part of the country.