ANALYSIS ON TREND OF DRIFTWOODS GENERATION CONSIDERING RAINFALL TREND CHANGE IN THE DEVASTIATED AREA DUR TO THE NORTHERN KYUSHU HEAVY RAIN IN 2017

Abstract

 Recently, driftwoods disaster has increased by climate change. It was occurred by heavy rainfall event such as the Northern Kyushu Heavy Rain in 2017. In the previous studies, a prediction model for the amount of driftwoods generation has been developed based on the logistic regression analysis. In this study, we analyzed the rainfall tendency based on the Mann-Kendall test, probable maximum rainfall and the amount of driftwood in two periods, that is, before 2017 heavey rain (till 2016) and including the heavy rain (till 2020). The results were obtained as follows: 1) The impact of climate change showed in the rainfall trend after 2017 in the study area; 2) The relationship between the prediction and the potential of driftwoods generation is strongly affected by the trend shift of rainfall due to climate change.