EXPERIMENTIAL STUDY ON DESIGN OF DRIFTWOOD CAPTURING FACILITY IN OMOTO RIVER

Abstract

In August, 2016, Typhoon Lionrock brought heavy rainfall and caused serious disaster by a large amount of driftwood in Omoto River, Iwate prefecture. Driftwood deposited at piers collapsed bridges and induced the flood damages by rising the water level. Moreover, driftwood was transported to the city area and destroyed the houses. Therefore, the development plan of the driftwood capturing facility was set up for mitigating of driftwood damages. The facility is structured to capture only driftwood using a river bend, the floating driftwood is directed into a catchment area of outer river bank by side-weir. In this study we conducted flume experiments to examine the structure features such as a position and shape of the side overflow weir that can efficiently capture driftwood into the catchment area. The results show that the capturing facility performed effectively the capture more than 65% of input driftwood.