Intertidal flat response adjacent to Shirakawa River mouth due to flush flood caused by Torrential rainfall on July 12, 2012 in Kumamoto

Abstract

The geomorphological response of intertidal flats adjacent to Shirakawa River mouth due to flush flood torrential rainfalls on July 12, 2012 was examined using field observation data. Mudflat profiles have been measured monthly along six cross-shore lines exceeding 1,000 m since 2006. Because all the measured profiles were approximated by a quadratic profile represented by the three parameters based on the results of Yamada and Kobayashi (2003), a vertical displacement parameter was used to understand the temporal variations of measured profiles. The maximum average accretion along the measured profiles due to this flooding was found to be 30cm and three times larger than those of past 8-years data.