ANALYSIYS OF TOPOGRAPHIC AND CURRENT INFORMATION AROUND OFFSHORE BREAKWATER AT ZENIBAKO BEACH IN HOKKAIDO

Abstract

 Three high school students drowned at Zenibako Beach in August 27th 2017. Firstly, we check the past newspaper articles about the disaster accident at Zenibako Beach. As the result, some accidents occurred at this area. Secondary, we made the field survey and acquired the topographic information. At the field survey, we got the topographic information and current information due to use ADCP. ADCP attached to a water motorcycle. During field survey, we pigmented the rip current by the sea water colorant, and the pigmented current was recorded as the aerial photography by the UAV. The photographed were used to make grid topographic data and calculated the average current velocity. When we made the field survey, Japan Coast Guard, Hokkaido Prefectural Police and Otaru Fire Defense Headquarters offered the information about the accident.