Snowcover components in northern Japan

Snowcover surveys were carried out in Hokkaido, northern Japan. Snowpack sa mples were collected using a steel pipe at 80 sites in 1988, 69 sites in 19 92, and 66 sites in 1996 and 2000 during the time when the water equivalent s of the snowcover are the greatest Spatial distribution maps of water equi valents and of the concentrations arid the accumulated amounts of hydrogen, non-sea-salt sulfate and non-sea-salt calcium ion of the snowcover drawn b y Kriging method are discussed. The distribution maps show that water equivalents and the accumulated amoun ts of hydrogen and non-sea-salt sulfate in all the sample years were larges t in the Japan Sea region, as were the ion concentrations of hydrogen and n on-sea-salt sulfate. It was estimated this was caused by air pollutants tra nsported from a great distance. The ratio of areas below pH 5.0 increased t emporally from 1988 (20%) to 1992, 1996 and 2000 (66-80%). This trend was e stimated to be affected by a decline of non-sea-salt calcium concentrations derived from alkaline road dust. In addition, the effect of snowcover comp onents was assessed by comparison between the acid loads of the snowcover a nd the acid neutralizing capacity of lake water. We found that lakes in the middle of the Japan Sea coast have the potential to be acidified by snowme lt.