DINAMICS OF DISSOLVED ORGANIC MATTER IN THE LAKE KAHOKUGATA BASIN

Abstract

 Source of organic pollutant of a moderate-scale lake, Kahokugata located in Japan sea side was examined by the monitoring of water quality in the basin. Increase in organic matter in summer season was due to increase in dissolved organic matter (DOM), and the seasonal variation of DOM could be explained by the seasonal variation of DOM in main inflow rivers. Increase of DOM was recognized in not only downstream but also middlestream of the inflow river, indicating that DOM came from upstream region. Furthermore, dynamics of DOM in a main river was examined by using EEM-PARAFAC analysis. The source of DOM was estimated to be eutrophic pond and rice field studded in mountain side.