Watershed characteristics and river water quality in the Abukuma River basin

Inference of water quality formation factors based on a one-year survey

Abstract

For the purpose of clarifying the river water quality and watershed characteristics such as land use and geology, field surveys were conducted for one year in the Abukuma River basin at 21 sites on the main stream and 40 sites on the tributaries. As a result, seasonal variations in the water quality were observed, and the water quality of the entire watershed was identified, which allowed us to confirm the influence of tributary water quality on the water quality of the main stream. In addition, we clarified that some tributaries had specific water quality. The Higashine River and the Ose River had high electrical conductivity and were classified in Na+-Cl- type, suggesting the inflow of pollution load from human activities. On the other hand, the Arakawa River was categorized as Ca2+-SO42- type, indicating a strong volcanic effect. Furthermore, we found the influence of land use in the electrical conductivity and major chemical constituents.