FEATURES OF EROSION PROCESSES MANIFESTATION DURING SNOWMELT AND HEAVY RAINFALL IN THE SOUTH OF RUSSIA

The purpose of the study was to determine the features of erosion processes during surface snowmelt and rainwater runoff. Materials and methods. The studies were conducted on the watershed within the Azov incline plain (central part of the Rostov region). Generally accepted research methods were used on temporary and permanent runoff sites. Standard rain gauges and measuring vessels were used to record the rain layer. Soil loss was determined by the volume of waterholes and the turbidity of the flowing water. Soil properties were determined by generally accepted methods in soil science and agriculture. Research results. During the observation period from 1970 to 2024, it was found out that snowmelt water runoff is affected by moisture reserves in the snow, the depth of soil freezing, and the temperature regime during the snow melting period. Melt water runoff occurs when the soil freezes to a depth of 25–30 cm and the water reserves in the snow are up to 20–50 mm. The runoff coefficient fluctuates within 0.1–0.8 with an average value of 0.4. In the warm period, the runoff depends on the amount of precipitation, rain intensity, degree of projective soil cover with vegetation and the runoff coefficient does not exceed 0.4 with an average value of 0.20–0.30. On dead fallows for soil loss with a mass of 20–30 t/ha, the runoff coefficient during showers should be at least 0.29–0.34, the same soil losses on fallow land from snowmelt are possible with a runoff coefficient of 0.40–0.60. Saturation with suspended soil particles of heavy rain runoff is 60–80 g/l, snowmelt water runoff – 12–18 g/l. Conclusions. Differences in the genesis of erosion processes and the amount of soil washed away during meltwater runoff and heavy rainfall are determined by weather conditions, water-physical and chemical properties of the underlying surface. During snowmelt, thaws increase runoff by 1.4–2.7 times, and precipitation by 3.7–4.0 times due to the kinetic energy of drops, which accelerate the process of snowmelt and destroy the structure of snow and soil.