Abstract
Because of the serious mercury pollution in 1950s, many measures and researches for pollution control have been implemented in not only Minamata Bay but also the Yatsushiro Sea. In this paper, the effect of river's outflow and wind stress on flow field will be presented by numerical simulation in order to reveal the characteristics of flow currents in the Yatsushiro Sea. It is pointed out that among three rivers, the Komenotsu River has the most effect on flow field in Minamata Bay. Wind stress could enhance the fluidity in the southern part of the Yatsushiro Sea. In particular, the northeast-southwest wind has more influence on the Yatsushiro Sea than the north-south wind. Under all the four cases of wind stress, strong currents obviously appear along the east coastline in surface's residual flow fields and the returning currents are found in bottom layer. It could change the characteristics of flow currents in Minamata Bay and be important for the transportation of mass in water areas.
