抄録
Sea bathing is an interesting activity for many people in Japan. However, a lot of swimming accidents occur every year. So many seashore accidents also occur in Niigata shore. The seashore accidents can be caused by various factors. One of them is rip current Rip current is a strong flow with the direction from shore into offshore. During the last few years, seashore accidents caused by rip current around artificial structure such as jetty of offshore breakwater are pointed out.
In this study, simulation of rip current is performed using two-dimensional finite difference model based on the Boussinesq equations. Simulation was carried out on virtual topography in which jetty is existed. Wave is generated from the offshore with the different directions and then characteristics of wave and rip currents around jetty are examined. Characteristics of incident wave are estimated using SWAN model. The simulation results show that rip current occurred at the tip of jetty if the wave direction angle is more than 40 degrees. As the angle of wave direction grows bigger, shore currents were developed. The jetty obstructed the shore current and directed the flow toward the offshore.
