Results of national lake surveys 1995 in Finland, Norway, Sweden, Denmark, Russian Kola, Russian Karelia, Scotland and Wales

摘要

Beginning in 1995, national lake surveys were conducted in the above North European countries. This report provides the first united evaluation of lake water chemistry in Northern Europe. It was found that, except for Denmark, the water was characterized by low ionic strength and had low content of nitrogen and phosphorus. In Finland, Norway, Sweden, Russian Kola and Karelia more than 50% of the lakes had low critical load (CL) values for sulphur acidity (S), while Scotland, Wales and Denmark had very few lakes with low CL for S. The highest percentage (27%) of lakes with exceedence of CL for S was found in Norway, while the values for Russian Kola, Sweden and Finland were 17%, 9% and 9%, respectively. In Scotland and Wales, critical loads for sulphur acidity were exceeded in 1% of the total lake population. For Denmark and Russian Karelia, too few lakes were sampled to give reliable estimates. This adds up to approximately 22000 lakes in Northern Europe where CL for S was exceeded. However, this number of lakes is a minimum as exceedence of CL for N was not included in the calculation due to lack of catchment data. 26 refs., 21 figs., 13 tabs.