The rim line of present gully can be deemed as a boundary to divide land of stduy area into two sections

namely

the ridge-land above this line

and the gully-land below it.But it is not very often to get the actual proportion because of some subjective reasons and/or some complex objective local characteristics.In this paper

we used aerial photograghs to divide the area into four different regions

selectd typical samples rir-photos

interpreted the rim line of gully

we can get the following conclusions.1)The proportions have some regional differences

but no zonal regularuty in this area.2)This propertions are not only restricted by palaeo-topography

but also impacted by human activities.3)Ridge-land amounts to about 35% in the region where deep-level land slip appears very commonly

45% in rivers source area and 40% in the rest areas.