Global climate change has most significantly affected the Polar Regions. The increase in air temperature has stimulated the melting of glaciers in the Arctic and Antarctic, which has contributed to changes in the formation of water and sediment runoff. However, there are very few quantitative estimates of the sediment redistribution in the periglacial catchments of the Polar Regions. Specific features of water and sediment runoff were studied within the catchment area of the Korabelnyj Stream located on the Fildes Peninsula in Antarctica near the Bellingshausen Ice Dome. The main aim of the study was to investigate the conditions for the formation of water and sediment runoff and to identify the proportional contribution of washout and erosion material coming from the periglacial and maritime parts of the catchment area to the sediment runoff of the stream. A set of methods and approaches, including: a) estimates of the sediment flow connectivity index; b) fingerprinting technique; c) hydrometeorological observations; d) large-scale geomorphological survey and others, was ap[1]plied to identify the conditions for the formation of surface runoff and washout, the mechanisms of sediment redistribution in various parts of the fluvial network and to quantify the proportional contribution of two main sediment sources to the sediment runoff of the stream. A fraction with a particle size of ≤63 μm was used for geochemical and spectrometric analyzes of soils and sediments. In total, the content of 34 elements was analyzed, i.e. 6 radioisotopes and 28 stable elements. It has been established that despite the significant differences in the relief of the near-glacial and maritime parts of the catchment area, the indices of sediment connectivity are quite close and amount to –1,79 and –1,35, respectively. A significant part of the material transported by temporary streams from the slopes of the catchment area is redeposited in relief depressions partially occupied by water bodies. The main volume of sediments, which is at least 60–66% of the total sediment runoff in the outlet section of the Korabelnyj Stream, comes from the periglacial part of the catchment area. This is due to the increased water discharge relative to the non-glacial part of the catchment area, which results from the melting of snow and ice accumulated on the ice dome, the high erosion of moraine deposits unprotected by vegetation, and the presence of an ice core in moraines, which prevents water filtration.

The change of bioproduction indicators on the kurum slopes of the western part of the Central Siberian Plateau under the modern climate warming is considered. The change in heat availability over the period from 1991 to 2020 was estimated in comparison to 1961–1990, and an increase in the sum of active air temperatures above 5°C and 10°C was noted by an average of 165°C and 8 days for both cases. The kurum slopes in the study areas were identified based on the processing of remote sensing data (satellite images of the Landsat series with 30-meter resolution and the Sentinel-2 with 10-meter resolution). The vegetation index series (NDVI and NDMI) were calculated for them using the archives of these images. This made it possible to assess the dynamics of photosynthetically active phytomass and moistening of the ground cover from 1992 to 2023. The index values were calculated as the maximum for the growing season (July-August) of the analyzed year for all low-cloud Landsat and Sentinel-2 scenes available for observation. In general, the interannual change in the NDVI and NDMI values averaged over the analyzed kurums tends to increase. There is a positive dynamic in the fluctuations of both vegetation indices during the study period. The kurum landscapes were typified by the rate of their overgrowth, kurums with the largest, average and smallest difference of the obtained values were identified, and their spatial distribution was estimated. The role of morphometric characteristics of slopes (including their exposure) in the processes of kurum overgrowth was analyzed. It was revealed that the maximum values of the growth of vegetation indices correspond to the slopes of cold exposures (northern, north-western and eastern), while the influence of steepness is insignificant. The positive dynamics of the values of vegetation indices allows suggesting the “greening” of kurum landscapes, which is also confirmed by the results of repeated studies at the key sites. The overgrowth of kurums includes the increase in the area and height of mosslichen cover, the appearance of shrubs, the active growth of young small-leaved trees and rare undergrowth of conifers. The “greening” of kurum slopes is accompanied by the melting of the char ice, therefore, the middle taiga kurums of the Central Siberian Plateau become more characteristic of the southern taiga, which indicates a change in zonal landscape conditions in the areas of their occurrence.

The article presents the results of the study of carbon accumulation over the past 3000 years in the Stolbovoye karst mire located within the Smidovich Mordovian State Nature Reserve on the southern border of the coniferous-deciduous forests of the East European Plain. Minerothrophic (sedge, wood-sedge, grass) and mesotrophic (Sphagnum, grass-Sphagnum, sedge-Sphagnum, cotton grass) types of peat are present in the peat deposits of the Stolbovoye mire. The mire is at the mesotrophic stage of development. The content of organic carbon varies from 37,2 to 53,4% (49,7% on average). The nitrogen content in peat shows significantly higher variations along the core compared to organic carbon, i. e. from 1,1 to 2,6% (the average value is 1,9%). The total carbon pool in the Stolbovoye mire is about 6,7 kg/m².

The data obtained showed that a fast-growing peatland is capable to sequester large amounts of atmospheric carbon. The carbon accumulation rate in the studied peatland varies from 32,0 to 158,4 g C/m²/yr, with an average of 68,9 g C/m²/yr, which is significantly higher than the average carbon accumulation rates in different types of peatlands during the Holocene. A relationship between carbon accumulation rate and climatic changes over the past 3000 years was not revealed. A significant increase in the rate of carbon accumulation at a depth of 60 cm (480 cal. years BP) could be associated with the high productivity of vascular plants even at higher levels of mineralization/humification of their residues.

Specific features of tidal fluctuations of sea level and tidal currents in the straits of the Kuril Islands are studied using numerical modeling. Two-time intervals, i. e. 02.06.1977–03.06.1977 and 11.10.1977–12.10.1977, were taken to compare the parameters of tropical and equatorial tides. The simulation results were verified with the field data. It was found that the straits of the northeastern part of the Kuril Ridge have a mixed type of tides with a predominance of the diurnal course, and in the southwestern part a semi-diurnal course prevails. The highest tides (up to 2,5–3 m) in the study period were observed on 02.06.1977 near the Kamchatka Peninsula and the Hokkaido Island, as well as large islands of the Kuril Ridge. Four main oscillation periods of 12, 12,4, 24 and 25,8 hours were identified, which corresponds to the S2, M2, K1 and O1 harmonics. Analysis of the data obtained showed that the maximum velocities of the depth-averaged currents reach 4,5 m/s. The highest speeds were recorded in the Kruzenshtern, Frieze and Sredny Straits. Estimates of the tidal flow have shown that semi-daily fluctuations are more pronounced in the straits with lower average depths during a tropical tide. In deeper straits, semi-daily fluctuations at tropical tides are very weak or absent at all, an example is the Bous[1]sol Strait. It is calculated that when using a two-dimensional model, the maximum values of the tidal flow are observed in the Boussol Strait, reaching ~40 Sverdrups (Sv).

Most traditional landscape maps are still focused on reflecting regular combinations of geocomponents depending on the genesis of the geosystem and the position on the gradients of environmental conditions. But they contain little information about the nature of relationships between the spatial elements of geosystems. The article proposes a new concept of geosystem maps, which substantiate the development of methods for reflecting the internal structure of geosystems as both a cause and a result of lateral connections between spatial elements. Thus a concept of a structural map of geosystems is suggested. The concept is aimed at strengthening the systemic understanding of heterogeneous spaces. We propose a program of maps belonging to the land[1]scape family, but providing an explanation of the lateral relationships between the spatial elements of a geo[1]chore, the resulting texture and the ability of a spatial structure to self-develop. The geochores are characterized in terms of the complexity of internal structure, the position on regional ecological gradients, the set of internal ecological gradients, the range of the ecological gradient values, the types and intensity of lateral flows, the texture, the tendency of changes in the complexity of the structure, the presence of sharp and gradual boundaries, and the stability of their position. A structural map is a GIS layer that is built over a traditional landscapemap layer showing lower-ranking geosystems. The main purpose of using structural maps is to get an idea of the degree of space mosaic, the possibilities and limiting factors of economic activity, as well as the stability of the properties of components and the spatial structure. The maps will show the conditions for choosing the land use types and technologies that are sensitive to the size of land parcel and lateral influences of neighboring lands. From the viewpoint of a land user, this information facilitates the assessment of the reliability of land in the performance of socio-economic functions and cost. We use a case study in the Arkhangelsk region to characterize the geochores structure. Structural map of a geosystem is not an alternative, but an addition to traditional landscape maps. In the future, more explicit regional-specific criteria will be needed to identify significant structural characteristics.

The paper presents the results of studying the spatial distribution of heavy metals (Zn, Cu, Ni, Cr, Sr, Co, Fe, Mn) in the bottom sediments of the bays of the Sevastopol region. The data obtained during the 2003 to 2018 expeditions are analyzed. The spatial distribution and accumulation of heavy metals in the bottom sediments of the Sevastopol, Kazachya and Balaklava bays are studied. Correlations between their content and the physico-chemical characteristics of bottom sediments of the studied water areas (content of C_org, CaCO₃, fractional composition) were obtained.

The metals with the same correlation coefficients for both the content of C_org and the silt fraction content are identified. These are Fe (r = 0,7) and Ni (r = 0,6) for bottom sediments of the Sevastopol Bay, Fe (r = 0,6) and Cu (r = 0,7) for the Kazachya Bay and only Ni (r = 0,8) for the Balaklava Bay. High correlation between Sr and CaCO₃ content (r = 0,8) has been established for bottom sediments of all studied water areas.

 It is shown that the spatial distribution of heavy metals is determined by physico-chemical characteristics of bottom sediments, which is confirmed by the magnitude of correlations in terms of the content of fine fraction and organic carbon, while the difficult water exchange with the open sea contributes to their accumulation up to maximum values.

There are unique types and subtypes of soils within the territory of the Crimean Peninsula. The growing tourist pressure on the region requires the increasing productivity of all industries, including oil refining. All this increases the risk of spills and leaks of oil and petroleum products during their transportation and pumping. However there is a large gap in the field of regulation of soil pollution with petroleum products (gross content), i. e. the absence of maximum permissible concentrations in the regulatory framework of the Russian Federation. To predict possible negative consequences of environmental pollution with oil and oil products, it is necessary to develop regional environmentally safe concentrations of oil and oil products, with due con[1]sideration of the local ecological and geochemical characteristics of soil types. The purpose of the study is to find the environmentally safe content of fuel oil in the soils of Crimea. Fuel oil contamination (1, 5 and 10% of the soil mass) was simulated in laboratory conditions. The study examined 7 types of Crimean soils, namely residual carbonate chernozem, drained solonetzic chernozem, dark chestnut solonetzic soil, brown carbonate soil, brown leached red soil, brown forest acidic soil and underdeveloped chernozem. After 30 days of the model experiment, the most informative biological indicators were determined in soil samples, i.e. biochemical (activity of catalase and dehydrogenases), microbiological (total number of soil bacteria and Azotobactersp. abundance) and phytotoxic (root length) indicators. It was established that fuel oil pollution had a negative impact on the biological properties of studied soils. The following series of soil resistance to fuel oil pollution has been obtained: residual-carbonate chernozem ≥ solonetzic drained chernozem = dark chestnut alkali = brown leached red-colored ≥ underdeveloped chernozem ≥ brown carbonate soil > brown forest acidic soil. The values of the maximum permissible levels of residual fuel oil content (MRLC) in the soils of Crimea were obtained: 0,33% in residual carbonate chernozem, 0,30% in dark chestnut solonetzic soil and solonetzic chernozem, 0,28% in brown carbonate soil, 0,35% in brown leached red soil, 0,33% in underdeveloped chernozem, 0,21% in brown forest acidic soil. The results of the study could be used in biodiagnostics of the ecological state and health of soils polluted with fuel oil.

The study aimed to identify the impact of shelterbelts on cultivated soils at three key sites in the forest-steppe zone of the southern part of the Central Russian Uplands. Automorphic chernozems were studied under 30 m wide longitudinally oriented broad-leaved shelterbelts; their plowed analogues – near the shelterbelts. The research was carried out in the area with heavy loamy and clayey typical chernozems. Over 60 years of shelterbelt growth, significant changes in the morphological, physical, and chemical properties of chernozems have occurred. Field soil moisture was analyzed during two growing seasons (2020–2021) showing that soils in the fields are moister to the west of the shelterbelts than to the east, primarily due to the western transport of air masses in the warm season. Compared to arable soils, those under shelterbelts demonstrated greater depth of the humus-accumulative part of the profiles (on average by 13 cm), signs of clay illuviation in the B horizons (glossy films and thin cutans), and fragmentary lightening of the middle and lower parts of the humus layer in the form of a weak skeleton deposit. There is a radial outflow of carbonates in soils under shelterbelts, compared to arable analogues. Three-meter deep soil profile contains on average 40–50 t/ha less carbonate carbon than the arable soils. These differences indicate an evolutionary transformation of soils under shelterbelts from typical chernozems to leached chernozems. Higher stocks of organic carbon have been recorded in the three-meter profiles of shelterbelt soils (on average by 27 t/ha) compared to arable soils. The composition of humus in chernozems under shelterbelts undergoes significant transformation towards a forest type: the content of fulvic acid increases in the 0–20 cm layer, and deeper layers show a maximum accumulation of humic acids, while the chernozem type of its vertical distribution remains characteristic of soils on arable lands. Lateral transfer of several substances (particularly phosphorus) from arable land towards shelterbelts soils has been established due to the desuction activity of tree root systems. Thus, shelterbelts activate a complex of autochthonous and allochthonous phenomena in soil cover, resulting in an obvious transformation of soils over a 60-year period.

Case study of the Kоpanovka reference section made it possible to investigate the structure of Upper Pleistocene deposits to verify the Hyrkanian horizon in the Lower Volga region. At the moment the synthesis of data on stratigraphy and malacofauna analysis, obtained by comparing our own field materials and published data, doesn’t allow identifying the Hyrkanian deposits in the Kopanovka section. Suggestions about the age of the Hyrkanian deposits in the area of the Tsagan-Aman section do not agree with numerous data on stratigraphy and the absolute chronology of the Upper Pleistocene deposits of the Lower Volga region. The Hyrkanian deposits were found only in the Manych River deposits and the northern part of the Caspian Sea; the age of their accumulation correlates with the MIS 5 stage.

The results of channel analysis of the Middle Irtysh River (from the state border to the city of Omsk) are for the first time presented. Despite its water management and transport importance, until recently it remained a practically unstudied river in relation to channel processes. The Irtysh River channel doesn’t comply with generally accepted ideas about the meandering of medium and small rivers and the predominant branching of large and largest rivers. It was revealed that the meandering channel within Kazakhstan is replaced by a branched one to the city of Omsk and downstream, and then, becoming a largest river, it meanders, only being complicated by islands that appear on the wings and in the top parts of the bends. It has been determined that the changing geomorphologic type of the channel along the length of the Middle Irtysh River (state border – Omsk) leads to the morphological complication of branches. Parallel-arm branches are widespread there, characterized by the elongation of large islands (L_o/B_o >> 3–4) and the straightness of the arms. The location of the channel along the right leading bedrock bank leads to the formation of branches below its ledges and irregularities that deflect the flow to the opposite floodplain bank. High anthropogenic load on the river (regulation of flow and interception of sediment by reservoirs, quarrying, and construction of dams) led to the incision of the riverbed, transformation of branches, as well as to the regression and shallowing of low-water branches, and, in other cases, to the emergence of branches and dispersal of runoff. The resulting changes in the Irtysh River bed lead to deterioration and complication of the waterway operation and water management of the river.

The article deals with the geographical study of a think tanks (TTs) phenomenon. Since the last quarter of the 20th century their creation and distribution has accelerated dramatically around the world. The spatial unevenness of their growth has reduced the macro-regional imbalances in favor of the global South, as well as rotated the top 10 countries lowering the United States position and rising those of the Asian countries, primarily that of China. TTs with basic functions are becoming a widespread phenomenon and a necessary attribute of a large city. The TT’ elite, consisting of large internationally recognized organizations, which are capable to influence the solution of the most difficult problems and endow selected megacities with competitive advantages, is very limited. 174 such structures are based in 89 cities of 55 countries. 25 of them are concentrated in megacities of Europe, ¼ each in megacities of America and Asia, and less than 110 in other regions of the world. As calculations show, their actual placement does not depend on a city’s demographic and economic potential, its investment attractiveness, or the level of globality and is primarily determined by the factor of being a capital city. According to the territorial concentration of the leading TTs, several categories of expert analytical centers of the world are distinguished: the largest (more than 15 TTs, Washington), large (10–15, London, New Delhi), medium (5–10, Beijing, Brussels), small (2–5, 28 cities) and emerging (53 cities). Despite the evident role of TT resource in increasing the international importance of cities and the country’s authority, Russia is still lagging behind and is represented in the world ranking of expert analytical centers by Moscow only.