THE CHARACTRISTIS OF THE DISTRIBUTION OF AN ACIDIC FALLOUT IN TOCHIGE PREFECTURE

Abstract

There are sulfate ion and nitrogen ion that acidify raindrops in rainfall. Those chemical ions are taken in rain by rain in or wash out. Until now, the authors have been investigating through measurement of acid rain in local area. And it is made clear that there are a seasonal characteristic of acidity in Tochigi region.
In this study, it is examined a characteristic of distribution about ion concentration or amount of fallout in rainfall. As a result, there is a tendency that sulfate ion concentration is high in summer, but low in winter on the whole of Tochigi region. And a rate of contribution of the origin of sea salt is not so much. But, there is a tendency that potassium ion is high in winter, but low in summer in Nikko. As a rate of contribution of the origin of a salt is a few, it is assumed that the origin of potassium ion and sulfate ion are in inland area