Abstract
In rain disasters of railways, there are also sediment inflow disasters originated from mountain streams away from railroads. Therefore, it is also necessary to observe rainfall in the watershed of the mountain stream, then regulate train operation in rainy circumstances based on it. However, the distance between the railway rain gauges for the operation regulation during rainfall is sometimes wider than the localized heavy rain area. Thus, we are considering applying the amount of rainfall analyzed with radar and rain gauges. In this paper, we clarified the size of the watershed and the distance from railroad to the furthest part of the watershed based on cases of sediment inflow disasters occurred in the past. And we analyzed focusing on distance dependency of rainfall at the time of disaster. As a result, it was found that the distance from railroad to the furthest part of the watershed is about 1.3 km. Since the correlation between the analysis precipitation amount of the mesh just above railroad and that of the area within 1.3 km from railroad is high, it is suitable to use the analytical precipitation amount with 1 km mesh size for the maintenance object.
