Abstract

Large drainage basins (the Yenisei, Angara, Lena, Selenga, and Amur Rivers) within southern East Siberia are characterized by weak gully dissection, and by a very uneven distribution of gullies. Basins of major rivers include 122.5 thousand gullies with an extent of 35.5 thousand km. The density of erosion forms averages 8.2/100 km², and the dissection density is 0.0238 km². It is established that gullies occur along river valleys of order 3-4 or higher and have predominantly an anthropogenic origin. Slope erosion forms prevail, and the proportion of bottom erosion forms is 1/3 of their total number. The varied natural conditions, combined with anthropogenic impacts, produce a highly mosaic pattern in the spatial distribution of gullies. For the last 230-300 years, four intensification stages of gully erosion were identified, which were associated with periods of abrupt changes in nature management.

Keywords: linear erosion, gully, catchment basin, degree of dissection density, density, south of East Siberia