Влияние типа водосбора на сток талых вод и потери почвы на черноземах

Abstract

Purpose: to establish the influence of the watershed form on the intensity of snowmelt water runoff and the bulk of eroded soil on the chernozems of Rostov region. Tasks: to analyze long-term (1970–2020) studies of surface runoff bulks, including various types (forms) of watersheds, from compacted and loose arable land; to establish patterns and to obtain the dependence of the bulk of washed soil on the runoff coefficient and the watershed form. Research methods are generally accepted; runoff sites were used on the slopes of Bolshoi Log in Aksai district Rostov region. The indicators of the erosion intensity which make it possible to judge the quantitative loss of soil volumes and bulk depending on the type of watershed, the volume of precipitation, the melt water runoff and other factors were studied. Results. It was found that the amount of soil washed off during melt water runoff varies within wide range, but in most cases does not exceed 3–10 t/ha. The erosion intensity most often coincides with the largest runoff layer, since in these cases it passes over the soil thawed from the surface. Soil washout is decreasing; in the period from 1970 to 1991, the average annual bulk of soil washed away from the fall plowed land was an average of 7.5 t/ha, and from winter wheat crops, 10.2 t/ha. In the next 20 years (1991–2009), soil losses from fall plows amounted to 4.6 t/ha, from winter crops – 6.8 t/ha, and in the last 10 years, respectively, 5.0 and 3.1 t/ha. Soil loss on the slope of the southern exposure was 0.65 from the northern one. In the rills of the northwestern exposure, the melt water runoff was 10–20 % higher than on the slopes between the rills; soil washout along the thalweg of rills reaches 40 % or more of the total bulk of washed out soil. Conclusions. These data, in combination with the conditions for the occurrence of the phenomena under consideration, are used for a scientifically grounded choice of a system of soil protection measures for an adaptive landscape farming system and their forecasting over time.