Recent climate science research is becoming possible to detect and identify the effects of climate change on meteorological disasters.However, although it is predicted that the risk of river floods will increase worldwide due to the progress of climate change, the spatial scale is smaller than that of meteorological disasters and it is caused by a complicated mechanism. It has been difficult to handle.

　Therefore, in this study, we first developed a method for detecting changes in flood frequency in flood inundation areas from high-resolution satellite images.By this method, it was found that the observations of the flood inundation area tended to increase at 1984% and decrease at 2013% during the 29 years from 29 to 41.It was also clarified that the change in the abundance ratio of water in the flooded area has a high correlation with the increasing / decreasing tendency of the annual maximum daily precipitation of the river.

　Next, the effects of global warming on large-scale floods in recent years were analyzed by a method called event attribution using a climate model.As a result, it was found that out of the 2010 floods that occurred from 2013 to 22, 14 floods changed their "susceptibility" due to global warming.In particular, spring floods due to snowmelt are said to be susceptible to global warming due to factors such as increased precipitation and decreased snow cover.

　The results of these studies suggest that climate change is already changing future flood risks.The group and others have also newly released a future flood risk map based on the latest CMIP6 warming experiment.The creation of such climate change risk information is thought to support appropriate analysis and proactive measures to reduce global warming damage.

reference:[Shibaura Institute of Technology] Understanding flood risks that are changing due to climate change