EFFECTIVENESS OF HAMAO FLOOD CONTROL BASIN LOCATED IN THE UPPER REACH ABUKUMA RIVER AT TYPHOON NO. 19, 2019

Abstract

 Numerical flood flow simulation was conducted to investigate the effectiveness of HAMAO Flood Control Basin located in the upper reach of ABUKUMA RIVER against an extraordinary flood in 2019. Because of the uncertainty of calculation condition due to the data missing and the bank overflow, an iterative process of calculation was employed in order to obtain the simulation results consistent with available field data. According to the numerical simulation results, the flood control basin was not effective for the extraordinary flood because its capacity was used up before the flood peak. The numerical results also suggested that, on the contrary, the bank overflow to the floodplain in the reach upstream from the flood control basin effectively reduced the flood peak.