EVALUATION OF THE IMPACT OF IMPROVEMENT OF FLOW LEVEES ON THE WATER QUALITY ENVIRONMENT IN LAKE KOMUKE

Abstract

 Lake Komuke, which faces the Sea of Okhotsk in Hokkaido, has improved its environment since it became a permanent lake mouth after constructing a flow levee in the Showa 50s. However, although the flow levee built in the Showa 50s is ageing and is undergoing renewal, the width of the mouth may change when the flow levee is improved or renewed, and the change in the width of the mouth may affect the environment inside the lake. Therefore, in this study, we evaluated the influence of changes in the width of the mouth of the lake, focusing on salinity and the amount of dissolved inorganic carbon on the lake environment as water quality items that affect the lake environment using the three-dimensional environmental fluid model Fantom. As a result, we proposed a construction method using existing sheet piles that can improve the flow embankment and channel revetment without changing the width of the mouth of the lake.