2022 年 10 巻 1 号 p. 415-429
Some rainfall disasters in railways are caused by sediment inflows, which originate from mountain streams far from the railway. Thus, it is necessary to calculate the rain that falls in mountain stream basins, as these data can be used to regulate train operations during rainfall. At present, the railway rain gauges installed to control train operations are too far apart to monitor localized areas of heavy rain. For this reason, the Japan Railway Company is considering using analyzed rainfall data to control train operations during heavy rainfall. This study clarifies the size of mountain stream basin areas and the distance between the railroad tracks and the farthest side of a basin based on the previous sediment inflow disasters to explore rainfall distance dependency. As these results show, the distance between the railway and the farthest part of the basin is approximately 1.3 km. At this distance, there is a high correlation between the amount of rain that falls in the basin and in the mesh directly above the railroad tracks. The findings show that it is sufficient to analyze the rainfall directly above the maintenance object.