Characterizing types of rainfall prone to sediment disasters and their future change in the Rokko Mountain in Hyogo

抄録

Estimating the future risk of sediment disasters in a changing climate has become increasingly important. To assess future changes in sediment disasters in the Rokko mountain area, we use the Critical Line Method (CL), which serves as the practical method for early warning of sediment disasters. This hydrometeorological approach utilizes a parametric curve known as the snake line, comprising hourly precipitation and soil-water index for representing the effects of short-term rainfall and long-term soil wetness, respectively. The geometric range of the snake line corresponds to various influential factors such as rainfall duration, peak intensity, and time series. We then utilize Radial Basis Function Network to quantify the geometric range of snake lines related to rainfall events prone to sediment disasters. Comparing the snake line ranges reveals contrasting stretching patterns in NHRCM with spatial resolutions of 5-km and 2-km. To understand this discrepancy, we further examine characteristics of all disastrous rainfall events based on the weather types and other corresponding features.