In ports located around estuaries, sedimentation of navigation channels and harbor basins occurs due to the deposition of discharged sediments from rivers. Reduction of such sedimentation as well as siltation has become an important research topic, for resolving the issue of insufficient sites for disposing of dredged sediments and also for meeting the need to reduce the cost of maintenance dredging. Maintenance and management of navigation channels and harbor basins are more serious problems in Southeast Asian and other countries that have ports located in the estuaries of large rivers.

In this research, which focuses on estuaries not only in Japan but also in Southeast Asian and other countries, we aim to understand the transport dynamics of sediments supplied by rivers, including the transport of highly concentrated fluid mud and its seasonal variations, and develop a model for simulating bottom sediment transport, focusing on coastal areas near estuaries.

During FY 2018, we conducted an on-site survey of sediment characteristics in the areas with a sudden change of depth in Niigatanishi Port (in December 2018). In addition, we conducted experiments to observe the behavior of the turbid water flowing into the dredged areas of the port, and evaluated the effectiveness of turbulence control to suppress sedimentation and siltation. We also conducted a collaborative study with BPPT, an Indonesian government agency, under a joint research agreement.