ABSTRACT
The photograph shows the debris flow cone (fan) formed by debris flows produced in the Kamihorizawa and Kamikamihorizawa ravines draining the mountain slope of the Yakedake Volcano (the mountain on the left-side of the picture). Taisho Pond, which is seen at the lower part of the photo, has been narrowed and made shallow by debris flows, and it is now appropriate to call it a river rather than a pond. The Kamikamihorizawa ravine where debris flow observations have long been carried out is the one that originates from the saddle part on the ridge seen in the center and flows to the right-hand side of the photo. The fan having the flattest slope is on the extreme right of the photo. It is the one formed by Kamikamihorizawa and it is still growing.
INTRODUCTION
