現地観測にもとづく土石流の流動解析

概要

論文の詳細を見る
Mechanisms of debris flow movement were analyzed through observations made in the headwater area of the Urakawa River, one of the debris flow-haunted area in Japan. Debris flows were observed by a visual recording system with video camera set up near the flow source, while the muddy flow associated with the debris flows was sampled downstream and its composition was analyzed. It turned out that the maximum suspended load in the flow amounted to 1180 g/1,which is nearly ten times higher than that in flows not associated with debris flows. This marked difference was due to the relatively high proportion of suspended particles of diameter 0.25 mm and larger. The analysis of the recorded video tape that in some of the debris flows, several flow heads appeared near their origin within a few minutes. In some cases the debris flow head was preceded by high density muddy flow. It was estimated that the debris flow develops into full strenght as its head alternately advances and hauls. This hypothesis was ascertained later by analysis of debris flow traces.
日本自然災害学会の論文
1984-03-31