抄録
Generally they make the master plan for debris flow countermeasure in the area around active volcano. That is called the Volcanic Sabo Master Plan. The object of the Master Plan is the runoff sediment volume by a probability of 1/100 rainfalls and the total runoff sediment volume during 5 or 10 years after the stop of eruption.
Especially considering the case that the counter-measure does not execute in the upper part of river basin because of the danger by the volcanic activity, urgent program is also made in the Master Plan.
But different phenomena occur in each active volcano, for example, debris flows occur continuously due to the sediment of pyroclastic flow in some volcanos. And the condition of execution is just different in each active volcano, as execution area for countermeasure is limited by the volcanic activity.
Considering the various condition in active volcanos, we need the actual countermeasure plan used the idea that we consider not only the total runoll sediment volume but also runoff sediment volume by time sharing.
In this paper I proposed the new urgent plan and the provisional plan for debris flow countermeasure in active volcano adding the Master Plan.
