Home – Home – Jornals – Russian Geology and Geophysics 2023 number 1

We report data on 9 samples of basaltic rocks and a spinel lherzolite xenolith collected during dredging in the area of Alba Guyot (Magellan Seamounts, Pacific Ocean). The data include ⁴⁰Ar-³⁹Ar ages of five samples and mineral chemistry of rock-forming and accessory minerals and glasses, with implications for the formation conditions of Ti-amphibole in basaltic melts. The upper slope parts at Alba Guyot and its satellite Oma Vlinder at sea depths of 3600 to 2200 m, are composed of ~1400 m thick basaltic rocks that formed within the 112 to 86 Ma interval (⁴⁰Ar-³⁹Ar plateau ages). Later, in its 60 Myr history postdating the Cretaceous volcanism, the guyot was exposed to erosion, which produced a plateau-like flat top, and underwent another pulse of volcanism in the Cenozoic. Miocene (<20 Ma) eruptions of basanitic magma on the Alba Gyot plateau were associated with petit-spot volcanoes. Judging by the absence of hyaloclastic deposits around those volcanoes and the age of the lavas, the Cenozoic eruptions occurred in subaerial conditions before the guyot submerged below the sea level. The Alba volcanics have greater contents of incompatible elements than typical oceanic island basalts (OIB), apparently, because they formed by low-degree partial melting of different sources: pargasite-bearing spinel peridotite of the metasomatized oceanic lithosphere, mainly for Cretaceous basaltic rocks, and/or garnet peridotite for Miocene petit-spot basanites. Multiple eruptions at Alba Guyot for 100 Myr may have been maintained either by the Southern Pacific Superplume in the region of the South Pacific Thermal and Isotopic Anomaly (SOPITA) in the Mesozoic or by translithospheric faulting originated at the lithosphere-asthenosphere boundary (LAB) in the Cenozoic.

We present new data on the chemical composition of the late Precambrian rocks in the upper part of the regional Balaganakh stratigraphic horizon (the Nugan Formation at the Baikal segment of the Sayan-Baikal-Patom belt (SBPB) and the Bugarikhta Formation of the Balaganakh Group at the Patom segment of the SBPB) and the U-Pb (LA-ICP-MS) age of detrital zircons from the Bugarikhta Formation. It has been established that the rocks of the Nugan and Bugarikhta formations resulted from the destruction of igneous and metamorphic rocks. The contents and ratios of trace and rare-earth elements in the rocks of the Nugan and Bugarikhta formations indicate a predominance of felsic igneous rocks in the provenance and the presence of rocks of mafic and intermediate compositions at the source of the terrigenous rocks of the Nugan Formation. The U-Pb age of detrital zircons from all rocks of the upper part of the regional Balaganakh Horizon is close to the age of the rocks in the basement of the southern margin of the Siberian Platform, which suggests that this basement was the main source of clastic material in the sedimentation basins. It is argued that the "pre-glacial" (pre-Marinoan) terrigenous deposits of the Nugan and Bugarikhta formations, as well as the deposits of the Ipsit Formation at the Sayan segment of the SBPB, accumulated in the Late Riphean (ca. 720-640 Ma), probably in postrift basins that formed immediately after the separation of Siberia from Laurentia at the early stages of the opening of the Paleoasian Ocean.

Cenozoic alkali basaltoids are developed in southern Transbaikalia (Daur-Hentiyn Range). They are represented by thin flows and nappes. Unlike the volcanic fields of the South Baikal volcanic region (SBVR), the investigated fields are not related to rifting. The volcanics from the Zharnichikha River flow were studied. By composition, they are referred to as basanites. The mineral compositions of the volcanics have been determined for the first time. In geochemical parameters the basanites correspond to mafic volcanics of oceanic islands. The P - T parameters of the equilibrium crystallization of olivine and clinopyroxene phenocrysts have been determined. For the calculated parent melt, the formation temperature was 1536 ºС, and the pressure was 3.28 GPa. The obtained original data on the isotopy of Sr, Nd, and Pb showed that the isotopic composition of the magmatic melt formed from the PREMA source, with a strong subordinance of the latter. Olivine clinopyroxenites (Ol + Cpx + Grt) were the probable mantle source for the studied basanites. The generation of basaltoid melts occurred under the influence of the mantle plume, which caused Cenozoic activation.

We present results of geochemical and geochronological (U-Pb, LA-ICP-MS) studies of plagiogranites of the Mt. Zmeinaya massif in the Nora-Sukhotino terrane. The studied rocks are of calc-alkaline series and peraluminous type. They formed in collision settings at the final stage of evolution of the Nora-Sukhotino terrane. The high Sr/Y ratios and low Y and Yb contents of the plagiogranites indicate that these are adakitic rocks. The trace element composition of the rocks suggests their high-pressure (>15 kbar) genesis through the melting of metabasites. The youngest zircon population from the plagiogranite has a mean weighted concordant age of 295 ± 4 Ma, which corresponds to the early Permian. With regard to the zircon morphology, the obtained age can be considered the age of the plagiogranites.

A highly accurate and detailed expert list of absorption lines of the ³²SO₂ molecule in the range 0-4200 cm^-1 has been created. The line centers in the expert list are determined from the experimental and calculated by the effective Hamiltonian energy levels, and the intensities are mainly variational data. The list contains 549200 vibrational-rotational transitions for 22 bands. The obtained centers and line intensities are compared in detail with the HITRAN2016 database and the AMES empirical list. Comparison with experimental data also shows that the accuracy of the variational calculation of the intensities of the spectral lines of the ³²SO₂ molecule depends on the vibrational quantum numbers.

The paper is dedicated to the memory of V.I. Tatarsky (1929-2020); however, it is not personalia. We present, as a brief review of our scientific works, the experimental and theoretical proofs of the E. Hopf's conjecture (1948) about the structure of turbulence as a space-time chaos of a finite number of interacting coherent structures. This review is the result of our many years research in the theory of turbulence. The theory of turbulence is a scientific direction that the authors have chosen under the scientific influence of V.I. Tatarsky.

The paper presents a tool for numerical simulation of the backscatter enhancement effect associated with double-pass propagation of laser radiation passing through an anisotropic non-Kolmogorov turbulence. It is shown that for variety of power-law exponents of refractive-index fluctuations, all other conditions being equal, the value of the enhancement factor also changes: it increases when the fluctuation spectrum becomes more and more low-frequency. For the anisotropic medium, the two-dimensional distribution of the enhancement factor allows remotely determining the spatial orientation of anisotropic inhomogeneities in a randomly inhomogeneous medium.

We propose and analyze a new method for total ozone columns (TOC) retrieving by interpreting satellite-measurements of outgoing thermal radiation of the Earth (spectrometer IKFS-2, Russian satellite "Meteor-M" N 2). The new method is based on an inverse operator which is constructed using ground-based standard observations of TOC (Dobson and Brewer spectrophotometers) and satellite measurements together with multilinear regression. The method is analyzed using standard ground-based TOC measured by Dobson at Voeikovo station, Leningrad region (Voeikov Main Geophysical Observatory). The analysis shows that multilinear regression between TOC from ground-based measurements and spectra of outgoing Earth radiation by satellite observations approximates TOC in Voeikovo for 2015-2020 with an error of 2.8% and a correlation coefficient (CC) of 0.97. TOC time series retrieved from the inverse problem by the regression method has an error of 3.1% and a CC of 0.97. The method suggested can be implemented in different Earth regions with satellite observations and TOC retrieved from ozone measurements at World Meteorological Organization (WMO) stations.

Results of measurements of the NO₂ contents in the vertical columns of the troposphere and stratosphere with the TROPOMI (Tropospheric Monitoring Instrument) aboard the Copernicus Sentinel-5P satellite in 2018-2020 are compared with the results of ground-based measurements at the Zvenigorod Scientific Station (ZSS) of the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The comparison of the satellite data with the ZSS data is carried out for the two products of satellite measurements: the NO₂ contents in the tropospheric and stratospheric columns. The correspondence between the results of satellite and ground-based measurements is characterized by the difference between them, linear correlation coefficients, and regression coefficients. The dependences of the comparison characteristics on the season, cloud conditions, and the height of the atmospheric boundary layer are revealed.

Results of experimental determination of the laser radiation extinction index by the gradient method from the depth profiles of the airborne polarization lidar return signal power for clear and coastal sea water in the subsurface layer are presented. Based on synchronous measurements of the polarized and depolarized signal components with the “Makrel” lidar operating at a wavelength of 532 nm, laser radiation extinction coefficients were estimated. It has been experimentally demonstrated that the polarized and depolarized lidar return signal components have different seawater extinction indices, and the difference can reach several ten percent. The depth profiles of the laser radiation extinction indices retrieved from these signal components for two series of lidar measurements are given. Such an integrated approach expands the possibilities of remote hydrooptical sensing.

The results of the analysis of changes in the quality of atmospheric air in the city of Ufa from 2017 to 2020 are presented. The influence of meteorological factors on the level of pollution in the city of Ufa is considered. The basis for the analysis are instrumental measurements at nine Roshydromet stations. The daily values of the atmospheric pollution parameter are calculated. Trends in the level of atmospheric pollution by various impurities are determined. Using the method of wavelet transformation, the characteristic periods in the variations in the level of pollution are ascertained. Using the cross-wavelet analysis, links between air pollution and dangerous meteorological parameters are revealed. It is found that the average concentrations of sulfur dioxide, xylenes, and toluene increased in 2017-2020; high level of atmospheric pollution is observed in the calm weather, light winds, and temperature inversions. The observed changes in urban air pollution provide unique grounds for experimental assessment of the impact of various anthropogenic factors on the qualitative composition of atmospheric air.

Based on ERA 5 reanalysis data and average daily surface ozone concentrations (O₃) measured at the TOR station from 1993 to 2020, the circulation mode, which contributes to the formation of extremely high ozone concentrations (95th percentile, further О₃95), is studied. It is found that for all months; an identical circulation mode is distinguished, characterized by an increase in surface air temperature in the area, which includes the TOR station. In addition to the increase in air temperature, О₃95 events are characterized by an increase in the southwestern component of wind speed. It was also found that these circulation features are associated with the development of meridionality, probably due to the propagation of waves in midlatitudes. The revealed circulation mode simultaneously contributes to the transboundary transfer of ozone and its precursors from the southern regions, the enhancement of ozone photochemistry, and the emergence of an additional source of ozone precursors - wildfires.

The polarization elements of the light scattering matrix in the vicinity of the backscattering direction of a perfect hexagonal column and a particle of a random convex polyhedral shape are studied within the physical optics approximation. The study was carried out for particles with a size of 10-100 microns for a wavelength of 0.532 microns. It is shown that, within the vicinity of the coherent backscattering peak, the polarization elements of the matrix have significant local extrema. At the same time, their angular width practically does not depend on the shape of the particle, but significantly depends on the size. The results are of interest for the interpretation of lidar measurements in cirrus clouds.

The paper presents the results of the experimental study of the dynamic characteristics of the laser fragmentation/laser-induced fluorescence (LF/LIF) process in nitrobenzene and para -nitrotoluene vapors under synchronized two-pulse laser irradiation. It is shown that if the values of the time delay between the pulses of fragmentation (248.4 nm) and excitation (247.87 nm) of NO-fragments are in the range 20-40 ns, the efficiency of the LF/LIF method can be increased by several times.

The article presents the results of research conducted by the staff of the Research Institute “New Economy and Business” of Plekhanov Russian University of Economics concerning the role of the Russian educational system in the space of the life of society, where it occupies an extensive sphere of intertwining direct and indirect interests, processes, actions of various parties: from an individual to the entire population of the country; from individual enterprises, organizations, to the entire production; from the employee to the sphere of labor, the entire socio-economic complex of the country. The system of higher education in the format of the Bologna system has been so deeply transplanted by many years of efforts into the entire vast sphere of Russian education, integrated with the spheres of science and labor. society as a whole, that it is difficult even to imagine not only an integral, but even a fragmentary one-time abolition of it. Based on almost 50 years of experience in serving Russian education in the teaching, scientific, and administrative fields, the authors of the article express their opinion regarding the demands seriously expressed in the Russian scientific and pedagogical community for the immediate abolition of the current system of Russian higher education (meaning the Bologna type) and the transition to a new, bearing the features of national tradition. The article notes that currently, the mechanism of simultaneous cancellation and transfer of the system is not yet completely clear. In the final section of the article, conclusions are drawn concerning some aspects of the fate of the Bologna system in the Russian Federation, other innovations of recent years, including the Western model in higher education, based on the experience of previous higher school reforms.

The study is focused on the prospects for the technological development of the oil and gas industry in the Krasnoyarsk Territory in the period up to 2030. The forecasts for the development of the oil and gas sector are analyzed, and groups of significant technologies are identified. A survey of experts was conducted; based on expert assessments, technologies were identified that are promising for the modernization of existing and deployment of new industries in the region; these are technologies for seismic exploration, well research, predictive assessment of reservoir productivity, 3D modeling of sedimentary basins; technologies that ensure efficient nature management and environmental protection.

The article is devoted to the analysis of the development of the system of territorial administration in the Russian Federation, as well as national projects as a key element of a set of program methods. The paper presents the historical excursion of the period 2000-2021, on the basis of which the key properties of the system of the regional structure of the Russian Federation were identified. Special attention is paid to the disclosure of models of regional management (model E.M. Primakova, model of recentralization, model of centralization of power), which formed the basis of the modern management system. A separate aspect investigated the integration of software methods into the management system at the federal level. According to the results of the study, a number of problems of the existing system of territorial administration of the Russian Federation, its main shortcomings, were identified. The authors proposed to adapt the mechanisms and tools of the management system to changing external conditions through the activation of digitalization tools at all levels of interaction, which in the future will contribute to the improvement of management processes and software methods. In the process of preparing the article, the methods of historical systemic and institutional analysis were used.

The modern study of digitalization is based on the differentiation of indicators and types of activities into separate subgroups, one way or another characterizing the level of the digital economy, within a limited (subjective) expert opinion. This study was based on the Network Readiness Index (NRI), as one of the indicators created to assess the level of development of information and communication technologies (ICT) and the network economy (based on Internet technologies) in different countries of the world. The article presents the results of a statistical study of the society’s network readiness index using factor analysis methods to qualitatively change the dimension of a large data array. The classification of the countries of the world according to significant integral indicators of the network readiness index by cluster analysis methods is carried out, conclusions are drawn on the formation of the components of the network readiness index in various typological groups. On the basis of the developed classification, mathematical models were built for each independent group of countries to establish the relationship of the effective attribute from the explanatory integral components - f1 - sufficiency of network space conditions and f2 - technological activity. The resulting factors were GDP, million US dollars (GDP) and the human development index, HDI (HDI) as indicators illustrating the dynamics of changes in the economy and the conditions for the development of society, which should be directly affected by digitalization processes.

The relevance of the exploration is due to the problem of increasing the regions competitiveness by applying the methods of concept catching up and advancing technological development to assess the regions technical efficiency. A comprehensive approach is used to measure the technical efficiency of the region by various methods (DEA-method and MPI, SFA-method and the Cobb-Douglas production function), extended by cluster and dispersion methods as an analytical tool for designing simulation strategies for the development of regions. The object of the research is the regions of the Siberian Federal District, which differ in scale, economic structure and level of socio-economic development. The results of the research showed the effectiveness of using an integrated approach to measuring technical efficiency to develop simulation strategies for the development of regions.

The article provides a statistical analysis of the development of the fuel and energy complex (fuel and energy complex) and types of economic activity (FEA) of the Russian Federation, the Republics of Bashkortostan and Tatarstan, to identify promising areas of development, in the face of unprecedented sanctions of the collective West. The current state and prospects of industrial production in the region, namely the volume of shipped goods of its own production, with an emphasis on the types of activities - DPI, production of petroleum products and coke, production of chemicals and chemical products, transportation and storage, are considered and analyzed in detail. The object of the study is the volume of shipped goods of the Republic of Bashkortostan for the period 2010-2021, as well as a comparison of the results obtained with the strongest industrial regions of the Volga Federal District (PFD), in particular with neighbors from the Republic of Tatarstan.

The article presents and discusses the problems of the realization of the national goals, aimed at strengthening and saving of the population health, improvement of activities of health authorities. Special attention is paid to the goals: preservation of the population, health and wellness of people; comfortable and safe living environment. Russian Federation, Southern Siberian macroregion (Novosibirsk, Omsk, Tomsk and Kemerovo regions, Altai Territory and Republic of Altai) were chosen as the object of the study. The informational basis of the study was formed by open data of the Federal State Statistics Service, territorial bodies of the Federal State Statistics Service, information available at the websites of regulatory bodies of the constituent entities of the Russian Federation, authorial assessments of the discussed problems, events and processes. Conclusions were drawn and recommendations were made.

The effectiveness of the ongoing digital transformations for the country as a whole is largely determined by the results of the development of modern information and communication technologies in individual regions. In 2014, the law determined the need to develop strategies for the socio-economic development of the constituent entities of the Russian Federation, as a result of which all regions developed relevant documents. In 2017, the state program “Development of digital economy technologies in Russia” was approved, which has been transformed since 2019 into the national program “Digital Economy”. This circumstance required updating the socio-economic development strategies developed in the regions. The article analyzes the content of the current strategies of the regions of the Central Federal District of the Russian Federation in order to determine the level of their compliance with the requirements of the national program “Digital Economy”. The result of the study is the development of recommendations for taking into account aspects of the digital economy in the structure and content of regional development strategies, as well as for developing measures to increase the level of compliance of existing regional strategies with the main provisions of the national program on digital economy. In the course of the research, the methods of qualitative analysis of test information, the comparison method, and the method of structural analysis were used. The research results contribute to the development of the theory and practice of regional management at the stage of the digital transformation of the national economy.

The article discusses the main problems that the Russian electrical industry faces in the modern period of sanctions restrictions. The article analyzes the situation with the provision of electrical engineering with imported materials on the example of the production of high-voltage cable fittings and high-voltage bushings, and also considers the current possibilities for their import substitution. The authors analyzed the possibility of supplying materials from new Russian suppliers of materials and suppliers from friendly countries, and came to the conclusion that under the current conditions, companies in the industry have the ability to fulfill the tasks of producing electrical equipment for the Russian power grid complex.

The concept of political activity is presented, it is determined that this is a special type of social activity, including domestic and foreign policy. The need for statistics for long-term actions, attracting supporters and denouncing opponents within the framework of political activity is revealed. The main techniques of political figures using statistics both to support and to oppose political leaders are described. Such a tool of political activity as digital populism is considered. Being essentially a powerful stream of absolutely inadequate statistical information that does not reflect current realities, it turns out to be to the liking of the electorate.

One of the most important directions of the state family policy is the elimination of orphanhood. The optimal solution to the problem seems to be the deinstitutionalization of the sphere of orphanhood and the arrangement of family life for children. Studies show that the measures taken by the state have a limited effect which actualizes the search for opportunities to expand the number of participants in preventive work and build a system of interdepartmental interaction. In this context, the purpose of the study was to determine the role of non-profit organizations involved in the prevention of orphanhood at the regional level. The study confirmed that they work effectively with orphans and foster families, and the grant support system has a positive effect on increasing the number and variety of projects implemented in the field of orphanhood prevention.

The problem of prematurity remains one of the most important in modern neonatology. The article provides an assessment of the economic costs for the care, nursing and rehabilitation of premature babies, and using the machine learning method, the lower limit of the gestational age for nursing and active treatment of this category of children is determined, taking into account the influence of the main risk factors for such outcomes as death and disability. The results obtained will reduce the economic burden of the state on the treatment of infants born with extremely low body weight.

The article considers the theoretical approaches to the definition of the “loyalty” notion depending on emotional component, satisfaction, attitude towards the product (service), organization, psychological assessment etc. An attempt was made to abandon not quite rational and productive approach of stating various characteristics in the notion. The paper suggests an authorial approach for studying loyalty, a number of variables of the research were formulated, which showed the possibility of use in different organization for loyalty monitoring following its approbation.

The article considers the methodical approaches to the solution of the problem of the assessment of the influence of digital economy on economic performance. The solution of the set problem is very important not only in the regional but national scale as well. The methodical approach to studying unevenness of digital development of the regions in terms of its certain segments (business and population) was suggested and tested. The analysis of the influence of digital economy on social and economic development of the regions was carried out. The assessment of the degree of the influence of the digital changes on the Russian economy in general was made. Conclusions were drawn. The data of the “Indicators of digital economy” statistical compilation were used as the informational base of the study.

In the context of the implementation of a national action plan related to the leveling of the negative consequences of the pandemic of a new coronavirus infection and ensuring, among other things, the growth of the Russian economy and the corresponding structural changes, as well as taking into account the external sanctions imposed on Russia and the various restrictions generated by them that restrain the development of the national economy, today the issues of developing and the speedy implementation of measures aimed at ensuring the technological sovereignty of our country. The article substantiates appropriate measures, including improving approaches to ensuring the modern level of technological equipment of economic sectors, increasing the role of research and development in the development of the domestic economic complex.

This article presents the results of geochemical studies of the main landscape components in the estuarine zones of the tributaries (Goloustnaya, Sarma, Kika, and Barguzin) and the coast of Lake Baikal. An assessment is made of the pollution of snow, soil, vegetation and surface waters. It was established that the most severe pollution is observed in the mouths of the Goloustnaya and Barguzin rivers. In the case of the Goloustnaya river this is due to soil and snow pollution as a result of the atmospheric transfer of emissions from the Irkutsk industrial center. The water in the Barguzin river is heavily polluted, largely as a result of pollutants from overlying catchment areas. In the mouth of the Sarma river, the main pollutants are due to recreational activities and enter soils and river and lake waters. The territory of the mouth of the Kika river is experiencing significant recreational loads but has relatively low levels of soil and water pollution. Accumulation of pollutants occurs on the geochemical barriers of soils and alluvial deposits. A rise of the water level in the lake does not lead to a critical level of permissible content of pollutants, and the quality of drinking water complies with sanitary standards. However, there are local areas with increased levels of toxic elements and substances in the coastal waters of Lake Baikal and in soils near coastal settlements (Sarma, Ust’-Barguzin, and Bol’shoe Goloustnoye).

The estuaries of the rivers are the most vulnerable objects of the lake system, which first of all respond to natural and anthropogenic changes of the river flow and lake level. Results from studying the content of persistent organic pollutants in the estuaries of the Selenga, Barguzin and Upper Angara rivers are presented. The content and profiles of organochlorine pesticides, polychlorinated biphenyls and polyaromatic hydrocarbons were determined in the natural water samples taken during the winter low-water period of 2022. The analysis of the data obtained by gas chromatography with tandem mass spectrometry in the mode of multiple reaction monitoring established the regularities of distribution and pathways of entry of persistent organic pollutants into the main tributaries of Lake Baikal. It was found that the pollution of waters of the main tributaries of the lake by organochlorine pesticides is not high, and the content of polychlorinated biphenyls is “trace” in nature and does not exceed the detection limits. Analysis of polyaromatic hydrocarbons origin in the estuaries is important because, apart from anthropogenic sources, there are also their natural sources. In this connection, we analyzed the ratios of concentrations of individual polyaromatic hydrocarbons, which are markers of the sources of their entry into the environment. Polyaromatic hydrocarbons in the natural water of the estuarine zones of the main tributaries of Lake Baikal have a mixed genesis (pyrogenic and petrogenic), but most of them are of pyrogenic origin. Data obtained for the qualitative and quantitative composition of persistent organic pollutants can be used for regional ecological-geochemical and ecological-hygienic assessments of the natural environment, identification of sources of anthropogenic impact on the natural environment and environmental risk assessment.

This article provides a substantiation for the transformation of the Lake Baikal coast in the area of the Selenga river under the effect of abrasion and accumulation processes associated with the Lake Baikal level rise during the construction of the Irkutsk hydroelectric power plant. It is shown that in the first years after the runoff regulation, an intense erosion of the entire coast occurred. On the basis of processing and comparing cartographic material from different years it was found that there occurred a significant decrease in the length and area of islands, peninsulas and sand bars in the Sor and Cherkalova Sor bays and in the Selenga delta. At present, destruction of sandy islands in the mouths of the rivers and the transport of sandy material along the coast continue during the autumn storms. It is shown that the decrease of the Selenga delta surface is associated with changes in sedimentation conditions. Coarse fraction of the solid runoff began to accumulate in the middle delta, and only fine suspended material enters the lake delta.

An analysis is made of the results from investigating the composition, production indicators and the distribution of macrozoobenthos in the Maloe More Strait of Lake Baikal for different years (1936-1941, 1951-1952, 2008, and 2014) covering a period longer than 70 years. The composition of macrozoobenthos showed the presence of representatives of the following groups: Hydroidea, Turbellaria, Nematoda, Hirudinea, Polychaeta, Oligochaeta, Isopoda, Amphipoda, Gastropoda, Bivalvia, Chironomidae, Trichoptera, Ostracoda, Bathynellidae, and Acariformes. A clearly pronounced azonality of the vertical distribution of benthic invertebrates is described, which is caused by the nature of the deep horizons, bottom sediments, and the development of benthic vegetation. Differences were revealed in the occurrence of macrozoobenthos on the northwestern and southeastern slopes of the bed of the Maloe More Strait. The study revealed a correlation between the biomass indicators of macrozoobenthos and changes in the Lake Baikal level as observed during the period under investigation.

It is established that when making decisions concerning the level management in Lake Baikal which possesses a unique biota and unprecedented hydrological parameters, yet being used in the mode of a reservoir of long-term regulation, it is necessary to take into account the requirements permitting the lake ecosystems to operate sustainably. Such requirements can be defined in the process of developing conceptual scenarios reflecting the impacts of various factors on the biota with due regard for the relationships between them and ecosystem components. We examine the possible factors of the impact of changes in water level on three components (microbial communities, vegetation cover, and fauna) of coastal ecosystems of Baikal and suggest relevant conceptual scenarios. A number of mechanisms of the influence of the water level on microbial communities are highlighted, and direct and indirect impacts on structural and functional characteristics of microbial communities of Baikal in different conditions of water levels are suggested. A two-level framework of factors affecting aquatic and terrestrial coastal vegetation with rising and falling water levels has been developed, and the influence of each factor was qualitatively assessed. Potential threats for the fauna (waterfowl and near-water birds were involved as a case) generated by the water level fluctuations were outlined in connection with biotopic and trophic relationships. In general, the heterogeneity and multidimensional character of the biota responses to the water level fluctuations has been revealed. It is emphasized that environmental integrity of ecosystems of fresh-water lakes, and the character and degree of impact on the biota from changes in water level of lakes still represent a “white gap” for the modern science. This is why the general schemes for ecosystem-based management of lakes have still not been developed.

The influence of long-term and seasonal fluctuations in the water level of Lake Baikal on species diversity of near-water and waterfowl vertebrates, their population density and breeding success is analyzed, the negative impact is revealed as well as a change in forage specificity and behavioral adaptation of species. The animal population of the coastal ecosystems of Baikal is unique and specific in many respects, as a result of which some aspects of its adaptation to long-term fluctuations in the water level are unique. An analysis was also made of data on changes in the abundance and spatial distribution of terrestrial vertebrates depending on the decrease or increase in the water level. The role of the construction of the Irkutsk hydroelectric power station in changing the structure of the population and the dynamics of the number of vertebrates is revealed. It has been established that in the nesting populations of waterfowl inhabiting the Selenga river delta, the rate of water level rise exceeding 1-2 cm/day causes a significant increase in the death of nests and eggs. Prolonged low water, which covered about 20 years, led to a decrease in the number of waterfowl, gulls and waders, which had previously remained numerous. We collected and analyzed information on the distribution and characteristics of the ecology of more than 120 species of vertebrates, permanently or seasonally living on the coast of Lake Baikal and leading an aquatic or semi-aquatic lifestyle. A zoning of the territory of the coast into 10 regions with different lengths, but with similar natural and climatic conditions, was carried out. 46 key areas have been identified, which are most sensitive to water level fluctuations. For these sites, the species composition of background and rare species of animals was established, and the areas of optimal habitat for animals and the zones of flooding of habitats were determined. The cartographic characteristics of two vulnerable territories of the Baikal coast are given.

The features of the influence of seasonal and interannual changes in the level regime of Lake Baikal on the populations of the main commercial fish species inhabiting the littoral zone of the northeastern coast which is the least exposed to the negative anthropogenic impact, are considered. Based on results of monitoring studies conducted during 1984-1990, it was determined that changes in water level of Lake Baikal and its tributaries have only a minor influence on the structure of the fish population in the littoral zone and biological characteristics of the main commercial fish species (black Baikal grayling and lenok) inhabiting this zone. The dominant role of black Baikal grayling in the ichthyocenosis at any water levels has been revealed. Lenok is a subdominant. Other commercial fish species (taimen, lake and river whitefish, pike, roach, dace, perch, and burbot) are not numerous and occur infrequently, mainly in pre-mouth sections of tributaries. It is concluded that one of the mechanisms of fish adaptation to the extreme changing conditions of the lake level regime is, undoubtedly, trophic adaptation aimed at consuming the most numerous and accessible food object. For the black Baikal grayling, they are unarmed small and medium-sized amphipod species and for lenok, they are stone and sand sculpins and large unarmed and armed amphipods. The most numerous food objects, such as imago of the Baikal caddis flies, are intensively consumed by all littoral fishes during their intensive emergence. This significantly reduces competitive relationships and contributes to better adaptation of fish to negative influences.

The water quality in the Listvennichnyi Bay has been investigated in terms of sanitary and microbiological indicators during the period of open water in the years of extreme water level in Lake Baikal (2017-2021). It was shown that the degree of fecal pollution in the Listvennichny Bay didn’t correlate with the water level or temperature, but related to the season and significantly varied on the different sampling stations. The abundance of sanitary-indicatory microorganisms in the summer-autumn period was significantly higher compared to the spring period which could be due to the raising anthropogenic impact through the season. Maximum abundance of thermotolerant coliform bacteria and Enterococci was determined at two sampling stations where raw waste waters reached the lake. At the other sampling stations including the background monitoring station, the water quality was mostly consistent with the SanPiN 1.2.3685-21 requirements. The interannual dynamics showed no significant differences in the thermotolerant coliform bacteria and Enterococci abundance. In the period of extremely low water level in Lake Baikal (2017) the abundance of autochthonous and allochthonous organotrophic microorganisms was significantly higher compared to the high-water years (2018-2021). Also, the abundance of both groups of microorganisms was similar in the autumn period, which can indicate the pollution of the Listvennichny Bay with easily decomposable organic matter and incompleteness of self-purification processes.

Presented are the results from analyzing a long-term series of observations (1976-2018) of the infection with parasites of the Baikal omul in the Chivyrkuisky Bay of Lake Baikal. Baikal omul (Coregonus migratorius) is one of the most ecologically important and valuable commercial fish species of Lake Baikal, dominating the structure of the ichthyocenosis of the unique reservoir. Parasites observed in each year of research are allocated to the core group; the others are classified as satellite species, and rare species are considered separately among them. There are 31 species of parasites in the Baikal omul in the Chivyrkui Gulf of Lake Baikal, seven species make up the core of its parasitofauna; 24 species are classified as satellite species, including 15 rare species. Among the parasites of the Baikal omul, of the greatest interest to researchers is Diphyllobothrium dendriticum, which has the highest epidemiological significance in Buryatia. The life cycle of the D. dendriticum is complex, proceeding with the change of three hosts: the first intermediate (Cyclopoida), the second intermediate (various fish species), and definitive ones (fish-eating birds and mammals, including humans). The Baikal omul is the dominant second intermediate host of D. dendriticum in Lake Baikal. The level of infection of the Baikal omul with Proteocephalus longicollis and Contracaecum osculatum baicalensis decreases, whereas it increases with D. dendriticum when the water level in Baikal rises. The multidirectional trends in the level of infection of the Baikal omul with mass species of parasites due to changes of the water level in Lake Baikal emphasize the importance of parasitological data for assessing the state of the ecosystem of a unique reservoir.

The issue of water-level regulation of Lake Baikal has been considered since the construction of the Irkutsk hydroelectric power station (1950-1959). Moreover, it remains relevant now, especially during periods of prolonged low water or high water. In this paper, we examine the theoretical, methodological and procedural framework for damage assessment, determine the essence of socio-economic and environmental-economic damage, and review domestic and foreign experience in assessing flood damage, because in the 21^st century the issues of damage due to changes in the level regime of a reservoir have been studied mainly from the standpoint of high water (inundation and waterlogging). It is shown that in Russia there is a certain lack of theoretical and procedural developments on this topic. Particularly acute is the lack of comprehensive economic and geographical work on the assessment of precisely socio-economic and environmental-economic damage. It has been established that one of the gaps in determining the damage from level fluctuations in a reservoir is terminological uncertainty (inconsistencies), which leads to an arbitrary interpretation of basic concepts and, consequently, to a large variation in estimates. We formulated a basic approach to the concept of damage in three main positions: estimated losses for identified economic entities (individual, society, and economic spheres of activity); a cost measure taken when assessing losses in any field of activity, including environmental; accounting for property rights (state, municipal and private), which is significant when considering compensatory measures. We summarized the existing approaches and methods for assessing damages, and identified their features and shortcomings with a view to the possibility for their further practical application.

In this article we consider the results from developing digital elevation models of shallow-water zones and coastal areas which can be potentially damaged due to changes in water level for particular sites on the shores of Lake Baikal, the Irkutsk reservoir and Angara river in the downstream pool of the Irkutsk hydroelectric power plant, which are needed for implementation of the project to assess the impact of regulation of the water level in Lake Baikal. When solving problems that take into account changes in the water level, it is necessary to use a combined relief model that unites surface and underwater relief. We consider the experience gained in the construction of combined relief models for such water bodies as the Irkutsk and Bratsk reservoirs as well as Lake Baikal. When building the combined relief model we tried to use all available data on the relief: topographic and pilot maps, the results of depth measurements using the echo sounder, and coastline contours identified using satellite images. We have developed several algorithms based on the use of Delaunay triangulation to combine data from various sources. A registry of key areas has been compiled for which it is necessary to perform additional data collection in order to update the coastal relief. We also consider techniques for obtaining digital surface models by using unmanned aerial vehicles of various types: quadcopters and aircraft-type drones. Currently we are carrying out digital aerial photography of selected key areas, where it is required to refine their terrain models.