THE INFLUENCE OF CLIMATE CHANGE ON FLOOD RISK IN HOKKAIDO

Abstract

In August 2016, 4 typhoons sequentially attacked Hokkaido region within 2 weeks and caused severe flood damage. Because this sequential typhoon attack is the first time in recorded history and remarked maximum rainfall amount on many observatory in Hokkaido region, it became one of a trigger that led river administrators to consider flood risk change associate with climate change. This study developed a method which can evaluate flood risk under both past and 4K warmer climate condition and applied to 2 river basins (Tokachi and Tokoro river basins) in Hokkaido by using a large ensemble simulation dataset. The results show annual maximum rainfall and flood risk under warmer climate conditions are bigger in both of two river basins.