THE PROPOSITION OF PREDICTION SYSTEM OF SHIP MOORING CRITERIA USING WAVE AND TYPHOON DATA AT HARBOURS FACING TO THE PACIFIC OCEAN

摘要

Ship motions are one of the biggest problems in harbours facing to the open sea. In Japan, the Nationwide Ocean Wave information network for Ports and HArbourS (NOWPHAS) system is already working, and its observation points contain a lot of offshore harbours. In this study, we mainly discuss about the prediction of the growth of swells or high waves using NOWPHAS and database of typhoons. At first, we choose an appropriate wave observation point and harbour facing to the Pacific Ocean ("A port", which locates south-west part of Japan). A port gathers information of mooring troubles in recent years, and we compare wave patterns as the time series in these trouble cases. Moreover, growth patterns of swells are analyzed by using observed database of waves and typhoons. It is cleared that most of mooring troubles is happened when waves grow rapidly due to typhoons or atmospheric depressions. This shows that the judge of the accurate timing about the evacuation seems to be difficult for moored ships by the prediction due to intuition with experiences. Some relations are obtained to construct the prediction model among waves, typhoons and mooring criteria. Then, we construct the new prediction model using these parameters, which is based on the theory of Kalman Filter. It is characteristic that this model do not require huge amount of input data such as other weather forecast models. The validity of the model is verified for some patterns of mooring criteria in "A port" due to typhoons. It is cleared that situations of mooring criteria can be predicted 2-48 hours later with high accuracy. This shows that the prediction model can offer important information for ships and harbours to operate with safe and suitable scheduling. It is expected to apply the prediction model as the operational system of ships in harbours facing to the open sea like the Pacific Ocean in the future.