ON EARLY DRAINAGE OF FLOOD FROM A CLOSED FLOODPLAIN USING AN INVERSE SIPHON AND COUNTERMEASURE AGAINST EXCESS FLOODS

Abstract

 Numerical flow simulation was conducted to study the performance of an inverse siphon to drain flood from the closed floodplain where the collapse of the Kinu River embankment caused a severe flood damage in 2015. The result showed that the siphon shortened the inundation period significantly. This numerical model was applied to design a flood retention basin composed by a side overflow dike at the upstream end and an inverse siphon at the downstream end of the closed floodplain. The result showed that the facility efficiently works to reduce the peak discharge of a flood exceeding the river channel capacity.