ЭРОЗИОННЫЕ ПРОЦЕССЫ ПРИ СТОКЕ ТАЛЫХ ВОД НА ЮГЕ ЕВРОПЕЙСКОЙ ЧАСТИ РОССИИ

Abstract

Purpose: to determine the regularities of melt water runoff and soil erosion on the chernozems of Rostov region for a long-term observation period of 1970–2021. Methods. Field experiments were carried out on slopes on compacted arable land (perennial and winter crops) and loose arable land (autumn ploughing). Measuring of melt water runoff and precipitation during the period of snow melting and soil washout was carried out on the water balance site of Stepnoy village Rostov region. The main physical and water-physical properties of soil during the snow melting period (freezing depth, moisture content of the upper soil layer 0.30 cm, water permeability) were studied according to generally accepted methods. Results. An analysis of field observations for the period from 1970 to 2021 was carried out for the parameter “snow water reserves before melting + precipitation during the snow melting period”, which averaged 47.8 mm over 52 years on compacted arable land and 43.15 mm on loose arable land, the runoff coefficient was higher on compacted arable land and amounted to 0.25 and 0.10, respectively; with appearance of surface runoff of 10.6 t/ha, this indicator increased to 5.9 and 20.7 t/ha on loose arable land, respectively. Mathematical analysis of the data made it possible to establish the relationship between the values of runoff, soil washout and water reserves in snow, the depth of soil freezing and water permeability during the runoff period. Conclusions. Long-term studies (52 years) found that there is a greater accumulation of water in snow on compacted arable land than on loose arable land, while the runoff coefficient was 2.5 times higher on compacted arable land, but the plants retain soil particles on compacted arable land, and soil washout on average over the years with the manifestation of surface runoff, was 10.6 t/ha, while on loose arable land this figure increased to 20.7 t/ha. The relationship between runoff rate, soil washout and water reserves in snow, the depth of soil freezing and water permeability during the runoff has been determined.