Abstract
The Sakata Port is located at the mouth of Mogami-River. It is sometimes claimed that there exist small-boats operational problems at the port entrance due to the chopping waves with interaction between the incident waves and the river flow. Nevertheless, sufficient study has not been conducted on the problems up to present stage due to difficulty of the engineering approach. This paper introduced the results of three types of the engineering study to solve the problems, witness questionnaire to the small-boats operators, field waves and currents observation with four seabed installed acoustic gauges, and the numerical simulation using the newly developed model with consideration of waves and currents interactions. It is concluded that the breakwaters extension project will be a good countermeasure.
