Lomonosov Geography Journal最新文献

{"title":"SENSITIVITY OF A 1D LAKE MODEL TO THE INPUT METEOROLOGICAL DATA","authors":"M. Tereshina, O. Erina, D. Sokolov","doi":"10.55959/msu0579-9414.5.79.3.6","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.6","url":null,"abstract":"The paper evaluates how the choice of a source of meteorological data used as boundary conditions and the changes in model calibration parameters affect the adequate performance of a model of lake thermo- and hydrodynamics. The quality of simulation of water temperature dynamics in a small lake by a onedimensional GLM model using data from an automatic meteorological station on the lake shore, a state weather station and two global reanalyses was quantitatively assessed. It is shown that the best modeling result (RMSE of water temperature calculation 0,8-2,0°C, Nash-Sutcliffe efficiency >0,7) can be achieved using data sets that explicitly provide incoming shortwave and longwave radiation fluxes. At the same time, good representation of the bottom water temperature requires correct setting of wind regime, which is only possible if data from instrumental ground-based observations at a stationary weather station are applied. Combining ground-based observations of wind speed, air temperature and humidity with radiation fluxes from global reanalyses makes it possible to achieve a calculation error ≤1°C at all depths.The analysis of model sensitivity to calibration parameters in case when the reanalysis data are applied showed that parameters related to wind mixing, i.e. the scaling factor for wind speed and constants related to the in-model description of wind impact energy, have the greatest influence on the final calculation error. If we change the intensity coefficients of other types of mixing during calibration it does not lead to an obvious trend in the quantitative estimates of modeling quality. It could also be reasonable to introduce correction multipliers to the values of air temperature and solar radiation fluxes, thus neutralizing the effect of unrepresentativeness of the meteorological data applied for a particular lake, as well as to correct the value of solar radiation extinction coefficient relative to the value obtained from the Secchi depth. The results of the study could be used to justify the choice of meteorological data source and to optimize the methods of calibration of lake thermal stratification models","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"135 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ADAPTATION OF AN AGRICULTURAL PROJECT TO THE REGULATION OF GREENHOUSE GAS EMISSIONS","authors":"D. Kovbashin, N. M. Svetlov, N. Dronin","doi":"10.55959/msu0579-9414.5.79.3.3","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.3","url":null,"abstract":"Using an original methodological approach, a model analysis of the adaptation of an agricultural project to the regulation of greenhouse gas emissions from agricultural land was carried out for the farms in the south of Russia. Emissions from both technological and ecosystem processes were taken into account. Methods of operations research and simulation modeling are applied to the study of two options for regulating greenhouse gas emissions, i.e. through market mechanisms focusing on the cost of carbon units in the EU and through the administrative control, which sets the emission limits. For each of the options, the optimal intensity of use was estimated for each land plot involved in the project.The proposed methodology supplements the scientific and methodological support for the analysis of the largescale agricultural projects under the state regulation of the impact of economic activities on the Earth’s climate. It is applicable to projects with a significant spatial dispersion of plots. As a result of the study, the scientific visions of the climate policy impact on the technological configuration of agricultural production were specified. A significant margin of sustainability of agriculture in the south of Russia to carbon market methods has been revealed; It is shown that as the restrictive administrative approaches are tightened, farmers prefer to stop the intensive use of areas with the highest productivity potential while maintaining the maximum production intensity within the rest. The totality of the results obtained is recommended for practical application for developing and analyzing investment agricultural projects, including the analysis of project risks, as well as for improving the state environmental and climate policy as a tool for analyzing its consequences.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"9 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DISPERAL OF THE LILIACEAE REPRESENTATIVES IN RELATION TO THE STRUCTURE OF THEIR REPRODUCTIVE ORGANS","authors":"P. S. Iovlev, A. V. Bobrov, M. Romanov, N. Zdravchev, A. S. Timchenko, M. V. Kandidov, N. D. Vasekha, A. A. Mikhaylova, M. Stevanovich, K. V. Kuptsov, A. N. Sorokin","doi":"10.55959/msu0579-9414.5.79.3.1","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.1","url":null,"abstract":"The Liliaceae family is a terminal one in the order Liliales sensu APG IV (2016) and consists of 15 genera with more than 700 species. The family’s geographical range covers most of the Northern hemisphere and extends through several natural zones, from forest tundra (Gagea species) to tropical forests (Tricyrtis imeldae Guthnick), within three continents, i. e. Eurasia, North America and Africa. Most Liliaceous genera occur both in Eurasia and North America. Representatives of Liliaceae develop coenocarpous fleshly indehiscent berries or dry dehiscent capsules. In most cases, multi-seeded berries themselves are a diaspore, whereas in the case of capsules, the seeds are normally a diaspora. The capsules play a vital role in seed dispersal. Structural adaptations of fruits allowed representatives of Liliaceae to spread into the territories that make up the modern range of the family.The aim of the study is to determine the principal patterns of fruit development for the representatives of Liliaceae with different types of dissemination. The study is based on the investigation of morphological and anatomical structure of fruits which is related to geography, ecology and biology of the Liliaceae taxa dissemination.The study has revealed that the wind is the most typical and widespread agent of dissemination for the investigated representatives of Liliaceae. The specialized capsules responsible for anemochory, i.e. auto-anemochory and anemochionochory (mainly in representatives of the ground cover of deciduous forests in temperate and subtropical climatic zones of the Holarctic Kingdom), are characteristic of representatives of the Lilioideae subfamily. Unlike the capsules supporting the anemochory, which actively participate in dissemination, the primary function of capsules of baromyrmecochorous representatives of Liliaceae is seed production rather than their dispersal, which is reflected in the anatomical structure of the capsules, with numerous intercellular spaces in the pericarp and almost complete lack of its lignification. The endozoochory of fleshly berries of Liliaceae is effective for dispersal by long-distance transport, primarily by birds. Supposedly, the ornitochory prevents dispersal among a large number of ecosystems, which is echoed in the ranges of Clintonia, Prosartes and Streptopus genera, representatives of the ground cover of coniferous and broadleaf forests of the Holarctic Kingdom.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"350 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CONDITIONS OF THE OAK FORESTS GROWTH AND CULTIVATION ON THE TOP SURFACES AND SLOPES OF THE NEAR-VOLGA AND ERGENI UPLANDS AND THE PLAINS OF THE SAL-MANYCH INTERFLUVE","authors":"A. S. Manaenkov","doi":"10.55959/msu0579-9414.5.79.3.5","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.5","url":null,"abstract":"Planted oak forests in the south of European Russia are of great conservation and economic importance. The widespread practice of their creation in dry steppes and semideserts dates back to the 1950-1970s and allows to form oak (Quercus robur L.) plantations with longevity up to 40-60 years. The aim of the study is to investigate the growth features of oak trees under different soil-climatic and biocenotic conditions and to suggest methods to increase their longevity.The research was carried out in 2011-2016 in the south of the Near-Volga Upland, the northern part of the Ergeni Upland and lowland plains of the Sal-Manych interfluve at 28 temporary sample plots using common methods of forest inventory and regression data analysis.It has been established that the viability of oak is limited by unfavorable topographic position of plantations, increased climate dryness (HC 0,4-0,6), high content of soil carbonates and shallow-lying horizon of their accumulation, as well as the presence of shrub layer and other competitors for moisture. Under these conditions, afforestation of depressions on the plains and shady slopes with pure plantations of oak and other species without shrubs should gain advantage. The methods of their creation should be modified depending on the topographic position of particular forest area and the climate dryness.So, the main soil cultivation in depressions could last 1-2 years, applying the system of black fallow with plantation plowing. It is advisable to keep 3,5-4,0-meter row spacing, frequent tending, and intensive clearing of young tree stands. Maturer plantations need careful sanitary-selective cuttings, mainly the low-type ones, and preservation of high canopy density. Poor water availability and deterioration of plantations should be prevented by construction of dams.Reclamation plantations of low marketability are created on flat areas after 2-3 years of deeper basic tillage. The carbonate horizon should be loosened and a large moisture reserve is needed. Row spacing of 2,5-3,0 meters is reasonable, accelerating the canopy closure. The area of tree nutrition is expanded by low-intensive uniformly selective cuttings, forming more open stands. The longevity of oak in already existing plantations could be increased by eliminating its competitors, such as living ground cover, shrubs and associated species.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"2 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MINERALOGICAL AND GEOCHEMICAL PARAMETERS OF SNOW COVER WITHIN THE ANTHROPOGENICALLY DISTURBED SITES OF THE NADYM-PUR INTERFLUVE (NORTHERN PART OF WESTERN SIBERIA)","authors":"A. Opekunov, M. Opekunova, S. Kukushkin, S. Janson","doi":"10.55959/msu0579-9414.5.79.3.2","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.2","url":null,"abstract":"The article analyzes the content of metals in solid aerosols and snow water sampled in the anthropogeni-cally disturbed and background sites of the Nadym-Pur interfluve. The results of microscopic studies of solid aerosols showed the presence of secondary minerals, technogenic formations, as well as a large amount of pyrite in samples from the eastern part of the study area. The maximum concentrations of metals in solid aero-sols were found in snow of the sanitary protection zones of waste disposal facilities, with the exception of Ca, which prevails in snow cover of Novy Urengoy (up to 10% of dry matter). The urbanized area is characterized by the highest values of dust load (up to 111 mg/m2 a day). The local contamination with Ba within the waste landfills in Novy Urengoy is associated with the sites of barite and drilling waste processing. We applied the factor analysis to identify the main metal associations characteristic of solid aerosols from different functional zones: Ca-Co-V-Mn (city), Ba-Sr-K-Na and Cd-Cu-Pb (waste disposal sites), Cu-Ni-Cd (the entire studied area). Based on the study of the content of dissolved forms in snow water, a high mobility of metals in the northern landscapes and its decrease in urban environment were revealed. The mineralogical and geochemical analysis of snow suggests the influence of the Norilsk industrial region on the eastern part of the Nadym-Pur interfluve, Zn, Cu, Ni, Pb and the mineral pyrite being the indicators. The risks of environmental pollution under the aerotechnogenic transport are associated with high content of Zn, Cu, Ni, Pb and Ba in solid aero-sols. The calculation of the Toxicity Probability Index (MERMQ) showed that some aerosol samples from the landfill sites have a high probability of biological effects. Using data on the chemical composition of soils and soil water, no visible effect of snow pollution on the growth of metal concentrations in soil and soil water was revealed, with the exception of local contamination with Ba, which led to a twofold increase in the content of the metal in the upper soil horizon.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"55 s62","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"СLIMATIC AND PHYTOCENOTIC EVENTS OF THE LATE PLEISTOCENE (MIS 5-MIS 3) AT THE SOUTHEASTERN COAST OF THE GULF OF FINLAND","authors":"N. S. Bolikhovskaya, A. Molodkov","doi":"10.55959/msu0579-9414.5.79.3.8","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.8","url":null,"abstract":"The paper analyses a debatable issue concerning the ranking of climatic-stratigraphic units within two marine isotope stages (MIS) - MIS 5 and MIS 4. Palynological records from the Mikulino interglacial sections of the northwestern Russian Plain which are most critical for correlations are reviewed. A representative series of numerical dates obtained by the IR-OSL method, and detailed palynological records enabled a detailed climatic-chronostratigraphic division of the Late Pleistocene sequence of the Voka reference section on the southeastern coast of the Gulf of Finland. The representative palynological spectra provide strong evidence of a warm interval of interglacial rank in the latter half of MIS 5, corresponding to the standard M6, M7, and M8 Mikulino palynozones. Additionally, they highlight a period of significant cooling during MIS 4, characterized by the dominance of periglacial vegetation formations in the study area. This challenges the viewpoint of the extensive Kalinin glaciation during that time, believed to have spread many hundreds of kilometers south of the Gulf of Finland. Data for MIS 3 reveal a two-fold alternation of interstadial and stadial (periglacial) climate intervals during the period between 39 ka and 33 ka.For the first time, detailed reconstructions and datings of climate-phytocenotic successions of paleoclimatic events approximately between 100 ka and 30 ka have been provided for the territory of the East European Plain (and Northern Eurasia as a whole). These events correspond to the latter half of MIS 5, MIS 4, and an interval between 39 ka and 33 ka during MIS 3.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"134 9‐12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SENSITIVITY OF THE KOLYMA RIVER RUNOFF TO MODERN CLIMATE CHANGE","authors":"A. A. Lisina, A. A. Sazonov, N. Frolova, I. Krylenko, Yury Motovilov","doi":"10.55959/msu0579-9414.5.79.3.9","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.9","url":null,"abstract":"The Kolyma River is a large river in the continuous permafrost zone. Its basin is subject to significant climatic changes. An information-modeling complex ECOMAG is employed for the study of water regime features and dynamics. ECOMAG calculates daily water flow rates at specified points based on meteorological data with a one-day resolution.This study analyzes the actual dynamics of water runoff and runoff-forming factors during the period from 1979 to 2013. A physical-mathematical model is adapted for the Kolyma River basin. Furthermore, the study examines the sensitivity of water regime characteristics to changing climate parameters. Calibration and verification demonstrated the ECOMAG’s ability to accurately reproduce observed water discharges for two points on the Kolyma River and the satisfactory performance on its tributary, the Bolshoy Anyui River. The ECOMAG model was for the first time employed for the Kolyma River basin, thus allowing the investigation of climate-related runoff changes. The preliminary statistical analysis revealed that if the average hydrological characteristics in the Kolyma River basin from 2000 to 2013 are compared with those from 1979 to 1999 a 5,1% rise of annual river runoff is evident for the Kolymskoye river section 283 km upstream the Kolyma River mouth (from 99,4 km3 in 1979-1999 up to 104,5 km3 in 2000-2013). The ECOMAG model also effectively captures changes in the annual water runoff and its intra-annual distribution.A rise in the mean annual air temperature by 1,3°C is characteristic of the modern time period. According to weather station data, the air temperature in March, April, November, and December increased by more than 2,5°C. The total annual precipitation increased by 8,3%, with September and March experiencing the most pronounced growth.To gain a more comprehensive understanding of the mechanisms governing the Kolyma River’s response to climate changes, the sensitivity of water runoff characteristics to air temperature and precipitation changes was analyzed using the ECOMAG model to generate artificial meteorological data series. The study demonstrates that water discharge is more sensitive to a 5% increase in precipitation than to a 1ºС rise in air temperature.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"25 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ISOSCAPES AND PALEOISOTHERMS OF THE HOLOCENE MEAN JANUARY AIR TEMPERATURE IN THE NORTHWESTERN SIBERIA (BASED ON STABLE OXYGEN ISOTOPE COMPOSITION OF ICE WEDGES)","authors":"N. A. Budantseva, Y. Vasil'chuk, A. Vasil'chuk","doi":"10.55959/msu0579-9414.5.79.3.7","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.7","url":null,"abstract":"Holocene ice wedges at 16 sites in the Northwestern Siberia were studied, the age of ice wedges was determined, and stable isotope data ( 18O and 2Н values) for all studied ice wedges have been summarized. The δ2H-δ18O ratio and the dexc values for ice wedge ice indicate good preservation of the isotope signal of winter precipitation in ice, which allows to use the obtained δ18O values for paleotemperature reconstructions. The isoscapes (lines of equal 18O values) created for the Holocene ice wedges and modern ice veinlets are generally submeridional; the 18O values decrease from west to east of the study area. Taking into account a new Holocene tripartite division scheme it was shown that the mean January air temperature (TmJ) in the Northwestern Siberia ranged approximately from -21 to -30°С during Greenlandian and the first half of the Northgrippian stage of the Holocene (11,4 to 6 cal ka BP) and approximately from -24 to -27°С from the end of the Northgrippian - to the Meghalayan stage of the Holocene (5,2 to 0,9 cal ka BP). The Holocene isotherms are close to the modern sub-meridional position and show an eastward decrease in TmJ values. Winter climatic conditions in the Northwestern Siberia were generally stable during the Holocene, meanwhile TmJ was on average 1-2°C lower than modern ones.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"321 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HEAT BUDGET OF THE BARENTS SEA SURFACE IN WINTER","authors":"A. Sumkina, V. V. Ivanov, K. Kivva","doi":"10.55959/msu0579-9414.5.79.3.10","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.10","url":null,"abstract":"Variability of the total heat balance (HB) of the Barents Sea during the cold period of the year has been studied. The cold period is that of cooling of the sea surface when the heat flux is permanently oriented towards the atmosphere. The contribution of two major components of the HB, i. e. sensible and latent heat fluxes, to the observed increase of the total winter heat transfer at the sea-atmosphere interface has been estimated. Data on short-wave and long-wave radiation fluxes, and sensible and latent heat values were obtained from the atmos-pheric reanalysis of the European Center for Medium-term Weather Forecasting ERA5. HB of the sea surface was calculated as a sum of short-wave and long-wave radiation fluxes and those of sensible and latent heat. The total HB, as well as the total flux of sensible and latent heat for the cold period were calculated by summing up the corresponding values between the start and end dates of the cooling season. Calculations demonstrated an increase in the sum of HB over the cold season for the northern part of the Barents Sea (up to 2000 MJ/m2 over 40 years), and a decrease in the southern part of the sea (up to 1000 MJ/m2 over 40 years). In the northern part of the sea, the contribution of sensible and latent heat fluxes decreases to 0,3-0,4. The observed trend of sum of HB over the cold season and its turbulent components could with high probability be explained by increasing difference between air temperature and sea surface temperature.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"5 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141686226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MODERN PROCESSES IN THE BEADED CHANNELS OF STEPPE RIVERS OF THE KHOPER-BUZULUK PLAIN","authors":"A. Tarbeeva, I. Krylenko, V. V. Surkov, N. Mikhailova","doi":"10.55959/msu0579-9414.5.79.3.11","DOIUrl":"https://doi.org/10.55959/msu0579-9414.5.79.3.11","url":null,"abstract":"Beaded-shaped channels (or chain-of-ponds), characterized by alternating lake-like extensions and narrow runs, are widespread on small rivers of the steppe zone of Russia. Extensions of channels - beads (pools or ponds), with a depth of up to 5-6 m, are of great importance for cattle breeding, providing a watering place during the dry periods of the year, when the flow of small rivers stops. However, the mechanisms of their specific channel shape formation are still debatable: it is explained by uneven siltation of channels, formation of whirlpools, groundwater discharge, karst processes or relict thermokarst. The aim of the study was to assess the role of water flow in the formation and support of the beaded shape of river channels. The tasks were to reveal the hydrological regime of the Kardail and Kupava rivers, determine the hydrodynamics of the flow in beads and runs, describe the characteristics of erosion and accumulation processes and the sediment transport, as well as to identify relict elements of the channel and floodplain structure that do not correspond to modern water state. Water flow of the studied rivers shows a long-term decrease in snowmelt flood, as evidenced by the rare flooding of the high-level floodplain, low rates of bank dynamics, and the discrepancy between the size of meanders and the width of the channel. The annual sediment load of the studied beaded rivers is low, estimated at 6,05 t/km2 in 2023. The reason is a low supply of sediments from the catchment area and low rates of erosion of channel bed and banks built of clay and silt. The present-day dynamics of water flow do not help the deepening and expansion of the beads. The flow reaches maximum speed (up to 1-1,3 m/s) in channel runs, while in channel extensions flow speeds drop to 0-0,3 m/s, supporting the sediment accumulation, despite the presence of whirlpools. A significant part of channel extensions is located on sites of former pools of the ancient meandering channel, inherited by the modern watercourse. On the former riffles the channel narrowed and a low-level floodplain was formed. Deep channel extensions were preserved due to the low sediment load and its fine composition, which prevents its rapid settling from the suspension. The results of the study suggest possible contribution of other factors to the formation of original deep pools, including the cryogenic ones.","PeriodicalId":158808,"journal":{"name":"Lomonosov Geography Journal","volume":"21 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}