A STUDY ON THE EFFECT OF FLOOD DEFENSE FORESTS ON THE LONGITUDINAL CHANGE OF RIVERBED DEFORMATION DURING LARGE SCALE FLOOD

In the heavy rainfall disaster in July 2020, floods and landslides of rivers occurred in a wide area and at the same time frequently, mainly in western Japan. In the future, even more severe rainfall is anticipated due to further progress of global warming, large scale water disaster frequently occurs, and there is a possibility of enormous damage. In recent years, discharge capacity has decreased due to the heavy growth of trees in the river channel. It is necessary to consider the influence of vegetation in the river channel to consider the riverbed deformation in the flood control plan. In this study, we set flood defense forests as a one-dimensional riverbed deformation model that simplified river channel in plain area. By considering the influence of flood defense forests on riverbed deformation, we could obtain the knowledge necessary to consider new flood control plans.