The N.I. Makkaveev Research Laboratory of Soil Erosion and Channel Processes was organized on the initiative of Professor N.I. Makkaveev in 1969 in accordance with the Resolution of the USSR State Committee on Science and Technology as a response to the Government Resolution “About urgent measures to protect lands from water and wind erosion of soils”. The paper presents that the basis of the new laboratory was formed by scientific teams (groups) created by N.I. Makkaveev since 1953 at Moscow University in various directions in the study of erosion and channel processes. Together with the development of the theory and methodology of erosion and channel studies, a unified doctrine of the erosion-accumulative fluvial process and erosion-fluvial systems, the laboratory’s research has always been closely linked to the solution of practical problems – protection of soils from erosion, regulation of river channels under development of water and other river resources, prevention of hazard manifestations of erosion and channel processes, on the one hand, and training of highly qualified specialists, on the other. The laboratory has overcome all the difficulties that have arisen in science development since the 90s of the 20th century and continues to function successfully at present, receiving support from the Russian Science Foundation, state and other programs, state contracts for the implementation of specific scientific and production tasks. The main scientific results of the 55-year activity of the laboratory are formulated.
Under the conditions of a changing climate, slope runoff from arable lands undergoes varying degrees of significant changes in different parts of the temperate climate zone. The article, based on a review of published data and the author’s generalizations, examines the main trends in the transformation of soil erosion in the largest agricultural regions of the world with an emphasis on the European Territory of Russia (ETR). For ETR, based on observations of slope runoff during snowmelt, a clear trend of its reduction was revealed, starting from the 1990s up until the complete cessation of the forest-steppe zone in the west and its replacement by mixed snowmelt/rainfall erosion in the west of the steppe zone. A general reduction in the rate of soil losses within the southern megaslope of ETR was revealed for all landscape zones except for the south of the steppe zone based on estimates of the rate of sediment deposition in the bottoms of the dry valleys of first-order catchments. It is shown that climate warming contributes to an increase in the frequency of extreme rainfall events, which is especially significant in Western and Central Europe. This trend is still less evident within the ETR. Structural changes in land use have affected Russian agriculture to the greatest extent in recent decades. Here, up until the beginning of the 21st century, there was a significant reduction in arable land, which since the beginning of the second decade of the 21st century has been replaced by the restoration of arable land areas in the forest-steppe and steppe zones. In North and especially in South America, over the past two decades, zero tillage has been used on significant areas of previously arable land, which has significantly reduced the rate of soil erosion. At the same time, in a number of regions of the forest-steppe zone located within the East European Plain, since 2014, the share of row crops has increased sharply (up to 30 % of the total area of cultivated land), which has increased the likelihood of severe erosion.
The headwaters of the river systems on the East European Plain between the boundaries of the Late Valdai (Marine Isotope Stage 2 – MIS 2) and the Moscow (MIS 6) glaciations developed during the last 150,000 years. During this time, there were at least three climatic episodes characterised by very high relative to modern surface runoff causing intense deep and backward erosion: at the end of MIS 6, in the second half of MIS 2 and in the middle Holocene. Watersheds cut by erosion systems have a mosaic geological structure, from hard-erodible glacial tills (moraines) to low-resistance sandy deposits. In moraines, the main deepening of erosional forms occurred in pre-Holocene time. Even relatively large forms such as balkas (dry valleys) have not yet reached concave longitudinal profiles. The general trend of their development was deepening. Short episodes of incision, occurring during climatic intervals with increased water flow, alternated with long periods of stabilisation. In the Holocene, the largest erosion events associated with episodes of anomalous intensity of atmospheric precipitation (probably heavy rainfall) are dated to the time interval from 6 to 3 thousand years ago. In different parts of this interval, single gullies appeared in areas with sufficiently high gradients and sandy substrates. These gullies quickly reached their ultimate size and now have graded concave longitudinal profiles. All other gullies cutting through moraines and bedrock were formed in pre-Holocene time, but are still far from being graded and have convex, convex-concave and stepped longitudinal profiles. The diversity of catchment areas, initial slope gradients, and properties of the geological substrate that determine its resistance to erosion has led to great differences in the evolution of the upper reaches of river systems within the Moscow glaciation area compared to the more homogeneous landscape conditions of the extra-glacial areas of the Russia Plain.
During the experiments, under various flow conditions, bed reliefs were created, on which dunes and waves of two additional levels were identified. The fundamental difference between dunes, which are forms of bed load movement involving mass transport, and waves, which represent the interface between moving dunes and the underlying bottom sediments, is defined and substantiated. A comparison of bed load discharge measured by the reference (volumetric) method directly in the flume with that calculated based on dune and wave parameters shows that the discharge calculated from dune parameters is closest to the reference. However, summing the bed load discharge obtained from the parameters of dunes and waves at other levels leads to a significant overestimation of the total discharge by an average of 66 %. Furthermore, the article presents results comparing the geometric parameters of dunes and waves and substantiates the conclusion that only the dune form of bed load movement should be considered when calculating flow rates, and that wave height should be considered when calculating guaranteed depths for dredged channel design.
The paper presents numerical experiments to evaluate the hydraulic characteristics of river flow and sediment transport parameters in the lower reaches of hydroelectric power plants on large navigable rivers. The results obtained made it possible to study the features of sediment movement in an unsteady water flow and develop certain recommendations for establishing boundary conditions when modeling channel transformations. The main conclusions obtained from the materials of numerical experiments are as follows: with the unsteady movement of water in the downstream of the hydroelectric power plant, sediment transport is activated, both in the summer observation period and in winter; the greatest discrepancies between hourly and daily average data are observed in the reservoirs located in the immediate vicinity of the hydroelectric power plant; the degree of increase in sediment consumption during the unsteady movement of water in the downstream of the hydroelectric power plant depends on the uneven regulation of water flow, the removal of the calculated hydraulic solution from the dam gate and the nature of changes in water content during navigation; in the immediate vicinity of the hydroelectric power plant, the intensity of sediment transport in winter becomes significantly less than in summer, as it moves away from the hydroelectric power station. The difference is decreasing; along the length of the river, as you move away from the waterworks, the intensity of sediment transport decreases. To test the results of numerical modeling, experiments were performed in a hydraulic tray. The obtained data are in qualitative agreement with the results of numerical experiments. During the experiments, it was found that the applied sediment consumption formulas show an overestimation of the calculated data compared with the measurement results.
The main natural factors determining the specifics of the Terek delta channel regime are related to increased sediment runoff and low channel stability. Sediment yield of the Terek is comparable to the largest rivers of Russia – the Ob, Yenisei, Lena, despite the fact that the water runoff is ten times smaller. For many centuries, people were adapting to the unpredictable nature of the riverbed and water regime of the Terek, which repeatedly changed the direction of its main flow after reaching the Caspian lowland. The present study presents the results of recent studies of the hydromorphology of the Kargalinsky channel, which is former avulsion channel and today is the main distributary of the Terek River delta, where more than 90 % of the total water and sediment runoff is discharged. An assessment is given of the variability of the rate and direction of channel changes along its length, the nature of the influence of fluctuations in the level of the Caspian Sea on the dynamics of the channel. The purposes of channel management are also discussed.
The paper present data on the impact of placer platinum mining in the Vyvenka River basin (Kamchatka Krai), based on long-term observations from 2003 to 2022, in the areas of placer gold mining in the Langeri River basin (Sakhalin Island) (2015–2016), the Tuul River (Mongolia) (2011–2015), and the apatite-nepheline deposits of the Yuksporryok River (Khibiny Mountains) (2017–2018) and copper in the Nautanen River basin (Sweden) (2017–2018) on the fluvial systems. Changes in fluvial processes of the abandonded mining sites influenced by reclamation measures are discussed. Examples of changes in sediment budget components are given, special role of effluents and channel erosion on sediment transport and its chemical composition in rivers is discussed. Specifically, the review is focused on the different stages of mining development and after their abandonment.
