1995 年 42 巻 42 号 p. 1-9
The dispersal processes of fine-grained red soils into coral reefs were studied at Manza Beach coastal areas of Onna Village, the Okinawa Island, Japan. The dispersal processes as the sedimentation of suspended sediment were studied immediately after the heavy precipitation in the area. In addition to this, the dispersal processes as bottom sediments were studied by grain size and other analyses on the bottom sediments. The red soils form front areas both as suspended sediment and as bottom sediments in the area of about 150m offshore from the estuary. The prevention of the outflow of red soils into the coral reefs is concerned with the technique how to settle or trap the red soils in the estuary. Several possible techniques are presented in this report.