Abstract
The most northern part of Kagoshima Bay was designated as "Kirishima-Kinko Bay National Park" on March 16, 2012. The Shigetomi-higata tidal flat in the national park was also designated as a seashore park. This tidal flat is important to biologically purify water inside Kagoshima Bay. Shigetomi-higata was productive tidal flat with abundant clams, but production of clams and other shellfish has been decreased recently. Thus collection of clams has been banned. Local benthic ecosystem would be affected by the change in sediment composition and topography. Therefore, understanding of the physical environment such as terrain and sediment characteristics should be examined. Terrain and sediment characteristic had been surveyed for four years from 2009 to 2012 in this paper. In addition, river discharge and representative wave characteristics which affect sediment transport and topography change are estimated.
