SALT DIFFUSION CAUSED BY OBSTACLES IN TWO STRATIFIED FLOWS

River transportation on Ishikari river has been proposed. But there are many technical problems to establish a system of river transportation such as seasonal fluctuation in water level, maintenance of a channel, bank erosion, accumulation of sand, effect on the fishing industry, problem of freezing, problems concerning loading, unloading and mooring facilities and so on. In this study the authors clarified salt diffusion caused by obstacles in two stratified flows