RAPID EROSION ON KAWARAGO COAST IN HITACHI CITY IN IBARAKI PREFECTURE

Abstract

 Beach has been severely eroded on the Kawarago coast in Hitachi City, and a famous bathing beach disappeared. To investigate the cause of the beach erosion, the shoreline changes between Oose fishing port and Kawarago Port were investigated using aerial photographs as well as a field observation on December 26 in 2015. Bathymetric survey data obtained between 1982 and 2013 around Kawarago Port were analyzed. The major cause of the beach erosion was the sand deposition behind the detached break-waters constructed south of Oose fishing port, and the secondary is the ground subsidence associated with the 2011 Great Earthquake.