Interactions of rip currents and coastal bathymetry change

Temporal interactions of shape of rip currents and coastal bathymetry are studied with numerical wave simulation. Boussinesq equations for coastal waves, which involve coastal currents as a solution, are combined with equations of littoral drift and deformation of coastal bathymetry. Uniform slope and the beach cusp with regular spacing are used as typical model coastal geography, and Tayuhama beach located in Niigata city, where the in situ rip current was observed was used as objective of field scale simulation. Results show that interaction between currents and bathymetry change enhances the rip currents more than the case with constant bathymetry. The shepe of rip currents and bathymetry changes obtained by the numerical study agree with theoretical study by Hino.