BENGGANG EROSION - THE INFLUENCING FACTORS

In the tropical and southern subtropic granite areas of South China, a special kind of small-scale erosional landform is widely distributed, called ''benggang'' by the local people. Many natural factors are res ponsible for the development of benggang, such as lithology, precipita tion, relief, vegetation etc., which are discussed in detail in this p aper. Study shows that the development of benggangs is the outcome of a joint operation of natural factors and human activities. Lithology, especially the characteristics of the granite weathering mantle, provi des material in which benggangs can develop, while intense rainstorms in a tropical monsoon climate act as a powerful force to cause benggan g erosion. The slope characteristics, such as steepness and exposure, control the spatial difference of the distribution of benggangs. The d evelopment of benggangs results from the reverse succession of vegetat ion induced by human activities in this region, and the density of ben ggangs is closely related to forest cover and unit timber growing stoc k.