BASIC STUDY ON FLOOD FLOW AND SEDIMENT DYNAMICS AROUND AN OPEN LEVEE IN KINUGAWA RIVER BY NUMERICAL ANALYSIS

Abstract

 It occurred widespread and simultaneous flooding and debris flow by the typhoon No. 19 in September 2019. Because heavy rainfall disasters occur frequently and heavy rain damage has become severe, we have to make effective use of various hydraulic structures. In the present research, the flood control functions of open levee in Kinugawa River were examined by 2D flow numerical analysis. The flood control functions were classified into two functions, that is, reservoir function and flood return function. As a result, it was suggested that the reservoir function does not work in steeply river such as Kinugawa River. It was also clarified that an inundated current with sediment deposit spreads wide in inland area in spite of the flood return function, because of the obstacles such as road embankment constructed at the open levees.