Geomorphological features and distribution of slopes in heavy snow regions in Japan where full-depth avalanches occur

Abstract

It is known that slopes where full-depth avalanches often occur have characteristic features, which have not yet been described in detail. The author defines an “avalanche furrow” as a steep furrow shape which resembles a scratched needle mark on aerial photographs. This study investigates morphological features of avalanche furrows and their relationship to full-depth avalanches by photo-interpretation and field surveys at sampled areas in Hokuriku District, Japan. It also investigates the distribution of avalanche furrows over the whole area of Japan by interpretation of 1:15000 scale color photographs. From this study, it is concluded that slopes with avalanche furrows have characteristics very similar to those of the slopes where full-depth avalanches have been reported to occur. Furthermore, it is shown that the general distribution of slopes where an avalanche furrow is seen corresponds to the heavy snow regions in Japan.