Abstract
The purpose of this paper is to make clear the change of cross profile of gullies develop-ing on the southern slope of the Nantai Volcano, located in the western part of Tochigi Prefecture. Types of gullies are briefly classified into two ; the gully having cliffs, and the V-shaped gully without cliffs. The former of them was investigated on the change of cross profiles, constituent materials and mass-movement during the period from spring in 1966 to summer in 1967. Main results obtained are summarized as follows.
1) During the period of heavy rain, the amount of deepening in the wider gullies is not larger than those in the narrower ones.
2) After establishing the rill along the gully bottom, the foot slope which is the intermediate slope between the cliff and the rill, increases temporarily its gradient by the mass-movement. The magnitude of slope change is less in the wider gullies than in the narrower ones.
