INVESTIGATION OF FLOOD CONTROL MEASURES USING RICE FIELDS IN THE KARUBE RIVER BASIN OF THE TAKAHASHI RIVER SYSTEM

Abstract

 Considering intense floods which have frequently occurred in recent years, flood control measure including flooding area called "River Basin Disaster Resilience and Sustainability by All" have been investigated. In order to investigate concrete flood control measures in medium and small river basin, it is important to establish a highly accurate prediction method for inundation areas and a quantitative evaluation method for the effects of flood control measures. In this study, the Karube river basin of the Takahashi river system was selected as the study site. The effect of flood control measures, which combines the suppression of pump drainage and the increase of storage by raising the ridges of rice fields, was investigated numerically using a river residential area combined inundation model. As a result, under the same rainfall conditions as the heavy rain in August 2021, it was clarified that when the pump drainage rate was reduced to 50% the inundation area could be reduced to the same extent by raising the ridge by 30 cm.