卷 19, 编号 2 (2023)

A new rather simple and, at the same time, high-precision method for solving Wiener-Hopf integral equations on a finite segment is proposed. Previously, when solving these equations, it was not possible to construct a single solution that is valid for all segment sizes. Various asymptotic and approximate methods have been constructed for large and small relative segments, which complicates the efficiency of the study. In this paper, on the basis of projection and factorization methods, including those developed by the authors, an approach is proposed that allows constructing a single solution for all relative sizes of the segment of the integral equation assignment. The type of properties of the kernels of integral equations for which this method is applicable is indicated in the article.

A study of the geodynamic activity of the Black Sea coast of Krasnodar Region during the 7th of August 2021 Caspian Pipeline Consortium accident was performed. The purpose of the study was to clarify the cause of the accident or the circumstances that caused the pipeline integrity failure. The research tool was a network of satellite geodynamic GPS stations Anapa and Gelendzhik. Analysis of GPS station movement plots shows the accumulation of stresses a few months before the accident. 1.5 months before this event, a geodynamic anomaly of vertical movement in the form of a bay-like subsidence of the earth’s surface began to appear. Analysis of the seismic-geodynamic situation does not give reason to link the geodynamic anomaly of the movement of the nearest GPS stations Anapa and Gelendzhik with the failure of equipment on the jetty device of the Caspian Pipeline Consortium, which does not have a rigid connection with the earth’s surface. One can assume the possible impact of geodynamic movements on the underwater section of the pipeline with a rigid attachment on the seabed. The basis for this is the latest research to study the resonant properties of oscillating lithospheric plates. It has been established that resonances that can provoke intensive movements of water masses in the pipeline zone can occur.

The results of the expedition of 2022 to study the coastal landscapes of the Lower Don are presented. By the method of ecological-geographical profiling 4 types of soils with different morphological as well as physical and chemical properties of alluvial soils have been studied. The soil cover of the key sites is represented by alluvial soils with different layers depth of the river alluvium and textural differentiation by granulometric composition. The upper horizons are turfy, the profile is stained with humus, in the middle part the horizons are of heavy loam granulometric composition with signs of fusion and salinization, in the underlying ones there are rusty-ochre spots of iron and blue spots of gley. Soil-forming sediments are alluvial deposits of different granulometric composition. Physical and chemical indices of soils characterize formation of alluvial soils of different degree of salinity, granulometric composition, density, etc. It has been noted that the upper layers are often non-saline and poorly compacted, while the underlying ones are slightly and medium saline, have heavy loam and clayey granulometric composition. In terms of pH, the upper horizons are neutral, while the underlying ones are weakly and moderately alkaline, which is due to the development of salinization processes in them. Expeditionary and cameral works have established that at present in the alluvial soils of the Lower Don a redistribution as well as changes in the structure of sandy alluvium along the soil profile occurs, so in the structure of the soil cover meadow and meadow-alluvial soils of large watercourses are transformed into low thickness alluvial layered soils, formed on floodplain and old sands, as a result of siltation and redistribution of solid sediment flows.

Along the Temernik River within the city of Rostov-on-Don, a high level of contamination with petroleum products and polycyclic aromatic hydrocarbons was noted in the water and bottom sediments. The most polluted sections of the river are in the area of the “Temernik” market, the Zmievskaya Hollow, the Botanical Garden of the Southern Federal University, the bus station and the mouth of the Temernik River. Excess of the MPC of petroleum products was detected in more than 80% of the analyzed water samples. The multiplicity of the maximum permissible concentration in water varied from 0.4 to 82.8 times. In the vast majority of the analyzed water samples of the Temernik River, the results of the luminescent method were 1.3‒13 times higher than the results of the infrared method, which indicates the accumulation of luminescent polycyclic aromatic hydrocarbons resistant to degradation processes. The obtained data indicate the chronic nature of oil pollution of the Temernik River water in the area from the Temernik market to the mouth. In the bottom sediments of the river, the concentrations of petroleum products varied from hundredths – 0.04 g/kg to abnormally high values ‒ 200 g/kg of dry weight. According to the averaged data obtained in various seasons 2018‒2020, according to the increase in oil pollution of bottom sediments, the Temernik River sections are arranged in the following order: Rostov reservoir, Upper reservoir, Upper reservoir 2, Kamyshevakha, Lower reservoir, Surb Khach, bus station, “Temernik” market, Zmievskaya beam, Botanical Garden, estuary. The concentrations of the amount of polycyclic aromatic hydrocarbons in the water of various sections of the Temernik River varied in the range of 91.6‒505.6 ng/l, in bottom sediments – 277.6‒2939 micrograms/kg of dry weight. The maximum concentrations of polycyclic aromatic hydrocarbons in water and in bottom sediments were found in the area of the bus station. The excess of the maximum permissible concentration of naphthalene (4000 ng/l) and benz(a)pyrene (10 ng/l) was not detected in the water samples studied. Naphthalene dominated in the composition of polycyclic aromatic hydrocarbons in water, fluoranthene dominated in bottom sediments.

The research area is located within the steppe zone of the south of the European part of the country, the largest river of which is the Don (Russia, Rostov Region). In order to study the syntaxonomic diversity of vegetation the classification of aquatic vegetation by the Braun-Blanquet method based on 40 geobotanical descriptions made in 2006–2022 in different watercourses of the Don River basin was carried out. The article provides information about the works devoted to the study of flora and vegetation of the Don River basin, which allow us to systematize data and draw conclusions about changes in the biodiversity of the studied territory: in the series “middle current – lower current – delta”, the depletion of aquatic flora occurs, species that previously occurred throughout the site (Nymphoides peltata (S.F. Gmel.) O. Kuntze, Trapa natans L. s.l., Salvinia natans (L.) All.), have become rare or not marked at all in the delta (Aldrovanda vesiculosa L., Caltha palustris L., Thelypteris palustris Schott, Stratiotes aloides L.). We explain the decrease in biodiversity in the direction from north to south by the increase in water mineralization. The results of the inventory of the highest aquatic vegetation are presented and the characteristics of the selected associations of classes are given: Platyhypnidio‒Fontinalietea antipyreticae (association Fontinalietum antipyreticae) and Lemnetea (associations Lemnetum minoris, Lemnetum trisulcae, Lemno minoris–Spirodeletum polyrhizae, Hydrocharitetum morsus-ranae, Stratiotetum aloidis, Ceratophylletum demersi). The most widespread (noted in the delta, lower and middle reaches) were communities of the following associations: Hydrocharitetum morus-ranae, Lemnetum minoris, Ceratophylletum demersi.

In 2023, the research vessel of the Murmansk Marine Biological Institute of the Russian Academy of Sciences “Dalnie Zelentsy” will be 45 years old. For four and a half decades, scientists from the MMBI RAS and other nautical organizations have traveled more than 700 thousand nautical miles on board the “Dalnie Zelentsy”. The number of measurements carried out on expeditions and samples taken comes to the hundreds of thousands. Tens of thousands of hours of marine mammals and birds observations have been made from the vessel. Numerous landings were made on unequipped Arctic coasts and calls at Russian and foreign ports. Currently, the vessel continues active expeditionary work in the Arctic.