SCIENTIFIC SUBSTANTIATION OF THE METHODOLOGY FOR FORECASTING THE SURFACE RUNOFF OF MELT WATER IN THE VOLGA AND DON BASINS
Although the statistical approach to forecasting spring slope runoff brings us closer to solving this problem, it does not allow us to obtain a sufficiently accurate and representative result. It is necessary to theoretically substantiate the genesis of the process of interaction of melt water with frozen soil. As a result of many years of research, a complex interaction of natural and anthropogenic factors in the formation of meltwater runoff has been revealed. This fundamental knowledge allows us to take a new approach to the assessment of the hydrological process and create a methodology for its forecasting. Introduction. The problem of combating soil erosion is very urgent and has not yet been resolved. Its solution should be carried out on the basis of knowledge of the laws of the erosion-hydrological process and the identification of its connection with natural and anthropogenic factors. When predicting the spring slope runoff, the influence of many factors is usually considered, but often unreasonably preference is given to snow reserves. Object. The object of research was the generalization and analysis of long-term experimental material obtained as a result of research by several generations of scientists from the All-Russian Research Agroforestry Institute and other research institutions. The aim of the study was to scientifically substantiate and develop a flow forecasting methodology. Materials and methods. Experimental studies were carried out at runoff-erosion stations in the forest-steppe, steppe and dry-steppe zones using the balance method. The runoff plots were laid on different agricultural backgrounds with a size of 20 by 100 m. The runoff was taken into account on them and the indicators necessary for assessing the runoff-forming role of natural factors were determined. Results and discussion. The author experimentally established and theoretically substantiated that out of all the variety of factors that many researchers take into account when predicting runoff, only three natural factors affect the formation of spring slope runoff: the depth of soil freezing, the moisture content of its upper layer, and water reserves in the snow. Freezing depth is the most powerful factor. When the soil freezes to a depth of less than 50 cm (or it is thawed), runoff is not formed regardless of the level of other factors. With a greater depth of freezing, the runoff is formed depending on the level of these factors. The role of snow storage in the formation of runoff is assessed ambiguously. Under some conditions, the runoff does not depend on the snow reserves, and under others, the runoff value is highly dependent on them, although they do not directly affect the runoff, but it is formed depending on the water reserves in the snow and the upper soil layer. Soil moisture plays an active role, and snow reserves passive. The algorithm has been developed for the interaction of natural factors and forecasting of slope runoff based on its relationship with these factors.