Author(s): T. Saita; S. Yano; A. Tai; T. Komatsu
Linked Author(s): Shinichiro Yano, Toshimitsu Komatsu
Keywords: No Keywords
Abstract: Recently, the frequency of red tides in Ariake Bay tends to increase. The nutrients-rich freshwater from rivers is pointed out as one of the reasons. In this paper, we introduce the results of observations on surface currents by using drifters to clarify the Lagrangian motion of freshwater from the Chikugo River. As a result, it is shown that the freshwater moved southwestward in a tidal period and was transported farther under flood conditions. It is considered that the westward excursion of the freshwater under calm conditions is considerably influenced by the river inflow rates, because the velocities at the mouth of the Chikugo River govern the Coriolis force. Findings of the present study imply that the freshwater from the Chikugo River can reach directly to Isahaya Bay, a branch of Ariake Bay about 30 km away from the mouth of the Chikugo River, within a tidal period.
Year: 2009