Natural preconditions and hazard criteria of gullies formation on the slope catchment area were analysed. A stochastic conception of gully development and methodology of gully growth probability assessment have been put forward. Outer and internal links in the gully-catchment area system were taken into account. Essential and sufficient conditions of gully generation have been established.

Drainage-areas of little and middle rivers in the Volga and Don basins were analyzed. The regularities of spatial sediment distribution and correlations between modulus of flow and sediment discharge in the different elements of erosion network are determined. River silt load and value of basin have low correlation, the causes of which may be the large spatial variability of accumulation processes outside the valley and significant importance of the riverbed erosion and accumulation for the formation of fluvial degradation sheet.

К 100-летию со дня рождения одного из ведущих геоморфологов нашей страны – Николая Ивановича Маккавеева.

An assessment of gully erosion hazard on slopes of drainage basins of small rivers and balkas was fulfilled using the method of extreme parameter calculation. Potential length of gullies was calculated that helped to divide slope drainage basins into “gully-generating” and “non- gully-generating”. The degree of number- and length-realization was evaluated for each gully-generating catch basin as well as the possible increment of gully network length. An approach to assessment of “risk” was suggested. The probability of gully rise was calculated using morphometric characteristics of slope catch basins obtained from topographical maps.

The paper concerns gulley erosion as the component of erosion-accumulation process on the catch basin. The analysis is based on some ideas of N.I. Makkaveyev. The gulley being the link between the area of watershed and the river and balka valleys has different functions - from the main source of silt load moving to the larger links of drainage network to the transboundary flux or accumulation zone.

The paper concerns gulley erosion as the component of erosion-accumulation process on the catch basin. The analysis is based on some ideas of N.I. Makkaveyev. The gulley being the link between the area of watershed and the river and balka valleys has different functions - from the main source of silt load moving to the larger links of drainage network to the transboundary flux or accumulation zone.

The general calculative scheme of banquette erosion was developed on the base of theoretical analysis and physical modeling. The scheme serves for prognostication the value, length and duration of erosion using easy determinable characteristics of banquette, made ground and most probable water runoff.

The classification suggested is based on morphological features of mouth alignments. The latter may be linked to the water edge or flood plain, to the bed of the balkas and dry valleys or to the water reservoirs. These peculiarities have a significant impact on the intensity of gullies growth and on their role in the erosion-accumulation processes within the catch basin.

Gullies and balkas on the territory of Bryansk are growing nowadays. Some factors advances their growth: coursing the streets along slopes, using the linear erosion forms as dumping sites or spillways, building of garages alongside the gullies etc. The calculations based on hydrologic and geomorphologic characteristics of gully-balka network of Bryansk territory helped determining the boundary of natural monument "Upper and Lower Sudki (Balkas of Bryansk)".

The behavior of gully-balka systems on the territory of scenic reserve "Krylatskiye hills" was analyzed and prognostic calculation of possible linear erosion value within its reach was fulfilled.

The paper presents the fieldwork measurements data and assessment of gullies' development hazard along the gas pipeline on one of the steppe site of Orenburg district. An approach to evaluation of gully growth duration is described. The most hazardous erosion forms and effective erosion control measures were determined.

Authors consider interrelations between number of gullies and their total length per unit area for gullies of different extension. The evaluations of average length and rate of growth of gullies for their different types were fulfilled. Some examples of calculation of gully formation period using original methodic are given.