Numerical simulation on the behavior of discharge from Chikugo River in Ariake Sea by using a 3-D flow model with wind shear stress acting on the water surface

项目负责人发现，雨季整个伊萨亚湾地区都形成了盐度层结，伊萨亚湾深部的盐度在某些情况下下降到普通海水的一半左右，在某些情况下可以恢复。这个项目是在假设盐度分层可能是由于流入有明海的河流的排放造成的，它的出现和消失可能是由伊萨亚湾的局部风造成的。研究结果表明：1)伊萨亚湾整个海域盐度分层的主要原因是奇库戈河的排放。2)偏北东北风将近水面低密度水团从阿里亚克海输送到伊萨克亚湾。3)西南风倾向于抑制低密度水团从有里亚克海进入伊萨亚湾，反之则促进其从伊萨亚克湾流出到伊萨克湾。

The project leader found that the salinity stratification is formed over the whole region of Isahaya Bay in the rainy season and that the salinity in the deep region of Isahaya Bay decreases to about half value of ordinary sea water in some cases and it recovers in some cases. This project was made under the hypothesis that the salinity stratification might be due to the discharge from the rivers running into Ariake Sea and its appearance and disappearance might be generated by local wind in Isahaya Bay. The obtained results are as follows: 1)The salinity stratification over the whole region of Isahaya Bay is mainly due to the discharge from Chikugo River. 2)The north-northeasterly wind transports the water mass of low density near the water surface from Ariake Sea to Isahaya Bay.3)The south-southwesterly wind tends to suppress the inflow of the water mass of low density from Ariake Sea to Isahaya Bay and to promote conversely its outflow from Isahaya Bay toAriake Sea.