ANALYSIS OF THE 2011 FLOOD FLOW IN THE LOWER SHINANO RIVER WITH THE BRANCHED SECTIONS

Abstract

Lower Shinano River is known as a typical low-lying river in Japan. This area was suffered from serious damages by inundation by the 2011 flood. Therefore it is important to clarify the hydraulic phenomena and the characteristics in the flood in order to establish the flood control plan.This study aims to analysis the flood flow in the river branches in lower Shinano River by the quasi-three dimensional numerical method using observed water surface profiles during 2011 flood. We could evaluate the flood discharge hydrograph and floodwater storage and elucidate the complicated mechanism of flood flow in the river branch in lower Shinano River.