MEASUREMENT OF INUNDATING FLOW FROM A BROKEN ENBANKMENT BY USING VIDEO IMAGES SHOOT FROM A MEDIA HELICOPTERIchiro Fujita, Yuichi Notoya and Takanori FurutaE3S Web Conf., 40 (2018) 06001DOI: https://doi.org/10.1051/e3sconf/20184006001