豪雨時の山腹崩壊に関する資料解析的研究

Abstract

The rainfall conditions and geographical features on slope failure are analyzed by using thefield data.The rainfall condition for the occurrence of slope failure or debris flow is clearly demonstratdon a plane of maximum hourly precipitation and daily or total precipitation by grouping thegeological conditions. Not only the condition for the occurrence of slope failure but also the densityare determined by the rainfall intensity and total precipitation, of which relation is different fromplace by place due to the difference of the resisting force.A lot of information is obtained concerning the geographical features on slope failure.The geographical condition for the occurrence of slope failure is clearly demonstrated in thewatershed area and slope angle. The slope failure is apt to occur at the slope steeper than 30and at the place where the slope angle changes downward from steep to mild.