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The article summarizes published and new geological, geochronological, biogeographical, paleomagnetic, and petrological-geochemical data to support the tectonic zoning of the Central Asian Fold Belt (CAFB) and its Vendian-Paleozoic geodynamic evolution as a complex folded structure consisting of deformed fragments of collisional and accretionary orogens. It has been shown that the Central Asian-Siberian Platform was formed in the zone of junction of the collisional and accretionary margins of the Siberian craton, similar to the modern tectonic interactions between the Indo-Atlantic and Pacific global tectonic segments of the Earth and Eurasia. It has been shown that in the Vendian and Early Ordovician, there were two active margins around the Siberian craton: the collisional Tuvo-Mongolian margin and the accretionary Kuznetsk-Altai margin, which separated the craton from the tectonic plates of the Paleo-Asian Ocean (Indo-Atlantic segment) and the Paleo-Pacific Ocean (Pacific segment), respectively.A distinctive feature of the Paleoasiatic Ocean plate is complex structure, which includes fragments of oceanic crust and Precambrian Gondwana microcontinents with fragments of the Grenville orogeny. Fragmentary Grenville zircons (1.3-0.9 billion years old) are widely found in the Vendian-Paleozoic sedimentary deposits of various geodynamic settings of the collisional orogen. A distinctive feature of the accretion orogen is the widespread presence of oceanic crust fragments and the absence of Precambrian blocks of Gondwana, and as a result, the absence of Granville-age clastic zircons in the Vendian-Paleozoic sedimentary rocks of various geodynamic settings. The Early-to-Middle Paleozoic Charysh-Terekta-Ulagan-Sayan-Olkhon suture-shear zone separates the collisional orogen from the shelf of the back arc basin located in the northern part of the Altai-Sayan folded region framed by the Siberian craton. The suture-shear zone consists of fragments of the Vendian-Early Paleozoic oceanic crust of the Back Arc basin, Ordovician blue shales and Ordovician-Silurian turbidites, Late Silurian-Devonian collisional metamorphic rocks and granites. Based on the structural position of the suture-shear zone and the data of petrological and geochronological studies, it is concluded that it is a subduction-collision complex formed at the site of the back-arc basin of the Vendian-Cambrian Tuva-Mongolian island arc. Late Paleozoic shifts and thrusts manifested themselves in the CAFB in the Late Devonian-Early Carboniferous as a result of the collision of the Kazakhstan-Baikal orogen (composite continent) with the Siberian craton with the formation of the North Asian continent, and in the Late Carboniferous-Triassic as a result of the collision of the East European and North Asian continents. As a result of collisional events, the initially linear structures of the collisional and accretionary orogens were deformed into large oroclinal folds, divided by shifts and thrusts into many fragments, where the Vendian-Paleozoic structures are complicated by thrust-fold deformations.

The toponyms of the Lena River basin, represented by hydronyms and oikonyms, are considered. To conduct an analysis of the classification of toponyms, geographical toponymic dictionaries, special regional studies, popular science, reference, encyclopedic and educational literature, materials from the periodical press and the media were used. A database of geographical names of significant tributaries, large lakes and settlements was compiled based on the sources used. The analysis of the information entered the database was carried out according to the classification of toponyms. The following semantic classification was used for the etymology of the identified toponyms (names reflecting natural conditions and processes; anthropotoponyms; production toponyms; trade and transport; toponyms indicating types of settlements; ethnotoponyms; memorial toponyms; religious and cult toponyms, etc.). The language classification reflects the settlement of peoples along the Lena River basin, where Tungus (Evenki and Even) toponyms are more common in the upper and lower reaches of the river, Yakut names are present in the Middle Lena, Russian names are mainly in the territories of the Zabaikalski Krai, Irkutsk Oblast and Amur Oblast. Classification by objects of toponymic nomination showed the prevalence of hydronyms (limnonyms and potamonims). A series of thematic maps was compiled, displaying the spatial distribution of toponyms of the Lena River basin, toponymic information. The sources for compiling the maps were publicly available topographic maps of scale 1:100 000, 1:200 000. The created GIS database and toponymic maps made it possible to systematize different types of toponyms identified in the territory of the Lena River basin to visualize their spatial distribution.

Process-based estimates of the hydrological consequences of the natural and anthropogenic components of climate change in the Selenga River basin were obtained based on the ECOMAG hydrological model and data from the CMIP6 ensemble of Earth system models. The aim of the study was to determine the impact of anthropogenic climate change on the river runoff formation of during the long low-water period of 1996-2017 and to provide forecast estimates for the near future of the 21st century. For this purpose, calculations were carried out using a physically-based model of runoff formation, previously verified against observational data, using two implementations of Earth system models: considering only the natural oscillations of the climate system and external impacts of natural origin, and considering the impact of anthropogenic activity, expressed in an increase in greenhouse gas emissions, including according to SSP scenarios for the future period. Warming in the summer period of 1996-2017 led to an increase in total evaporation, which, together with a decrease in the amount of precipitation and an increase in runoff losses due to infiltration, led to a long-term low water content of the Selenga. Under natural climatic conditions, the annual runoff of the Selenga in 1996-2017 should have been 28 % greater, including the spring flood runoff by 10 % and the summer-autumn runoff by 30 %. In the near future, on average by 2040, under scenarios SSP2-4.5 and SSP5-8.5, a decrease in the annual runoff of the Selenga by 9-25 % is likely, especially in the summer-autumn period.

The article examines the specifics of demographic processes in the Irkutsk agglomeration against the background of the regional situation. In the context of the theories of the second demographic transition and the second stage of the epidemiological transition, authors analyze the features of fertility and mortality in large and small cities and the suburbanized zone of the agglomeration. Based on the features of the age composition of fertility and mortality, the authors show the existence of three types of population reproduction in the onesomes space of the agglomeration: in a small town, large cities and suburbia. The first type was formed during the period of mass Soviet urbanization in the mid-20th century, the second - at the turn of the 21st century as part of the second demographic transition. The latter combines two oppositely processes: a decrease in mortality and an increase in life expectancy as part of the second stage of the epidemiological transition and an increase in the birth rate of migrants from the city while maintaining in general its urban age structure.

The article describes the development of an online cartographic service for the rapid assessment of the quality of the urban environment within urban agglomerations. The server being created allows users to obtain information about the quality of the urban environment at a selected point based on a customizable set of criteria. The paper describes a methodology for forming an index of the quality of the urban environment, which includes an assessment by various groups of criteria, such as climatic, social, environmental conditions, transport infrastructure, etc. For each criterion, a rating method is used, which allows forming a final index. The territory of the Irkutsk urban agglomeration was chosen as the object of the study. The work describes the stages of creating a service, including collecting and processing data, developing algorithms for calculating indices, creating a website based on a geoportal. As an example, the calculation of the index of accessibility of comprehensive schools and proximity of industrial enterprises is considered. The created system will make up for the lack of services for rapid assessment of the quality of the urban environment and will become available to a wide range of users, including professionals and ordinary citizens, will make it possible to use extensive data for assessment.

Various factors affecting the housing market in the Irkutsk urban agglomeration, both for urban areas and for peri-urban area are evaluated and systematized. The research was based on the open data of the site CIAN 2024. Evaluated the statistical relationship between housing prices and factors of density of greenery, density of social infrastructure, transport accessibility and the presence of factors of negative and positive neighborhood in suburban and urban areas. It was found that for large Siberian agglomerations center-peripheral and coastal price differentiation is characteristic. Irkutsk agglomeration is characterized by higher population growth due to suburbia and the imbalance of housing affordability in the city: the largest population growth was recorded not only in the most attractive urban areas with high housing prices, but also in areas with low, middle-price areas are growing noticeably slower. The study showed fundamental differences in the differentiation of housing prices in urban and suburban areas. It was concluded that for urban areas the most important is the density of social infrastructure and transport accessibility, the criminal environment and the least - ecology and greening. In the peri-urban area, the most important factors are the type of permitted use of land (which is primarily related to the availability of engineering infrastructure), transport accessibility, natural and environmental factors (proximity of objects of negative neighborhood).

Landscape-hydrological zoning and mapping of the Central Ecological Zone of the Baikal Natural Territory has been performed in accordance with the runoff-regulating functions of landscapes, which determine the transformation of precipitation into surface and groundwater runoff, conditions for the redistribution of runoff seasonally, reduction of peaks of floods and improvement of water quality. The runoff-regulating level of landscapes is determined by the structure of the vegetation cover, the structure of the soil-ground layer and morphological characteristics. These structural parameters determine the environmental protection and water-ecological functions of the natural complex, which are expressed in water protection, soil protection, anti-erosion, anti-avalanche and other properties of the territory. Orographic elements and types of landscapes play a leading role in the spatial landscape-hydrological differentiation of the territory. The individual landscape-hydrological characteristics of the natural complexes of the districts are substantiated by a comprehensive analysis of forest-growing and geo-morphological features, structural and typological characteristics of soils. The purpose of zoning is identify natural complexes with various landscape and hydrological functions that reflect the intensity of drainage, water-ecological potential and environmental conditions of the territory. The performed zoning of the Central Ecological Zone of the BNT is based on the analysis of cartographic, analytical and expedition materials, as well as the results of previously performed landscape-hydrological, geo-morphological and soil studies within the boundaries of the Baikal natural territory. The constructed landscape-hydrological map shows areas with different morphological, soil-vegetation and hydrological conditions. These natural conditions characterize the level of runoff regulation, the intensity of soil migration of matter, the danger of erosion and mudflow processes, and, as a result, show areas with different environmental protection and water-ecological properties.

The work is based on field landscape-geochemical and office analytical studies conducted in 2015-2024 on the coast of Lake Baikal and the adjacent territory. Samples of surface water and soil were collected at key sites, and chemical and physicochemical analyses were carried out in the field and laboratory conditions of the V.B. Sochava Institute of Geography, Siberian Branch of the Russian Academy of Sciences (IG SB RAS) using standard methods. Increased contents of F^-, NH₄⁺, PO₄^3-, Pb, Ni and oil products were found in surface waters near populated areas on the coast of Lake Baikal, exceeding the MAC values. The main anthropogenic sources of environmental pollution are: construction and road enterprises, thermal power plants, boiler houses, railway and motor transport, waste dumps. The sources of surface water pollution with phosphates and ammonium are housing and communal facilities. In the soils of the coast of Lake Baikal, local high content of Mn, Pb, Ni, Co, Cr, Zn, Cu was found, exceeding the MAC near the settlements of Listvyanka, Baikalsk, Bolshoe Goloustnoe, Sarma, Kabansk, Turka, Ust-Barguzin, Severobaikalsk and Nizhneangarsk. The maximum concentrations of chemical elements in soils in relation to the background also have: Ba, Sr, V and oil products, but do not exceed sanitary and hygienic standards. High concentrations of HM in coastal soils are possibly associated not only with anthropogenic sources, but also with deposits of rare metals.

The problems of mapping the relief of deep-sea surfaces are mainly associated with the impossibility of obtaining data on the geological structure of the discovered forms, which often makes it difficult to unambiguously determine their genesis. The paper provides examples of using additional information to increase the reliability of conclusions about the relief of the bottom surface of a deep-sea basin. To clarify the genesis of the bottom forms of the Baikal Basin, published data from seismic and geophysical studies of the bottom surface, and core drilling materials were widely used. As a result of the analysis of the obtained material, the genesis of the remnants on the underwater slope of South Baikal was established, and it was found that the sharp turns of the valleys of some canyons are explained by the lithological, structural and textural features of the slope deposits.

To study the adaptive capacity of crop production under changing climatic conditions, a database of spatiotemporal characteristics of hazardous and adverse natural-climatic events during the warm season has created at the Laboratory of Geoecology and Geosystem Dynamics at the Institute of Monitoring of Climatic and Ecological Systems the Siberian Branch of the Russian Academy, for the southern taiga of Western Siberia. The components of the database, its structural features, and its capabilities of spatial assessment and cartographic visualization of the studied phenomena which it allows are shown. Based on the analysis of meteorological data from 32 stations over the last 20-year period, a series of thematic and integrated maps illustrating the territorial and temporal patterns of hazardous and adverse natural-climatic events have been created within a GIS environment. Intra-regional patterns in the intensity, frequency, and duration of these events were identified. Statistical assessment and mapping have revealed that climate-induced risks to the local crop production system are not decreasing and that their spatiotemporal patterns are heterogeneous. The highest risks for plant growing occur during the spring season and are associated with the hazardous phenomenon of late spring frosts. During the summer, climatic hazards in the northeast of the region are associated with intensive precipitation, while in the southwestern they are caused by hot weather. It has been noted that adverse events occur more frequently than hazardous ones and, in combination, create a high risk-forming potential. A detailed analysis of the spatiotemporal characteristics of the studied phenomena and the cartographic visualization of the results enable monitoring of developing hazardous situations, risk forecasting, and the formulation of recommendations for minimizing losses in crop production.