コウスイ ニ フクマレル ムキ セイブン ノ カガクテキ トクチョウ (ダイ1ポウ)

Since acid-rain is a very serious problem in environmental chemistry, the sample collections over a wide area and characterization of the constituents in the rainfall and snowfall are often necessary. In this study, the values of pH and electric conductivity (EC) were measured, and the concentrations of Na+, NH4+, Ca2+, Mg2+, Cl-, NO3- and SO42- were determined in the precipitation. The 20 precipitation samples collected from May in 1989 to February in 1990 showed the pH values under 5.50. The lowest one was 3.97. This indicates that acid-rain and acid-snow fall in this area. It was observed that the pH values of the precipitations depend on the NO3- and SO42- concentrations. The Mg2+ concentration in the rainfall closely interrelated to the Ca2+ concentration, while in the snowfall the Cl- concentration interrelated to the Na+ concentration. The concentrations of Na+, Ca2+, Mg2+ and Cl- in the snowfall were higher than those in the rainfall. The EC decreases with increasing the precipitation, and it is forecast that the average wind velocity affects the EC value in the snowfall