Geography and Natural Resources最新文献

Abstract

This article presents the main results of the joint academic atlas mapping of the transboundary Baikal region obtained by the Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences (SB RAS), and the Institute of Geography and Geoecology of the Mongolian Academy of Sciences with the participation of other academic institutions and universities. A structural–semiotic analysis of the created atlases is carried out, and it is shown that the number of information–semiotic modules in each atlas can vary and depends on its subject matter, territorial coverage, and purpose. The analysis of the internal semiotic structure of atlases is carried out through the prism of a unified system of syntactic classification of conventional signs and methods of graphic display on the example of a number of atlases. The system of structural–semiotic organization of atlases is proposed to be methodically and practically supported with the help of geoportal methods and technologies for their use in creating new digital atlas projects.

Abstract

Questions of the evolution and taxonomic status of the humpback whitefish Coregonus pidschian and its relationships with the complex C. lavaretus sensu lato (s.n.) are as of yet unresolved problems in the study of Coregonus fauna. With the exception of the Amur basin, the only representatives of the genus Coregonus in native Mongolian fauna are humpback whitefishes (Kottelat, 2006; Dulmaa, 2015). The taxonomic status and origin of the previously described forms found in Mongolia require clarification. The study analyzes their relationships with other representatives of the Coregonus genus using phylogenetic reconstruction based on the mtDNA cytochrome b gene. It is discovered that there are two divergent mtDNA lines of humpback whitefishes coexisting in lakes of the Darkhad Depression. A potential history of their migration to Lake Dood Tsagaan through the upper reaches of the Yenisei River is proposed. The hypothesis of the Darkhad Depression being a refugium that gave birth to a quick-growing form of the Issatchenko whitefish (C. fluviatilis Isaczenko, 1925, Yenisei basin), separate from the C. lavaretus complex, is disproven. It is shown that a form conspecific with the Issatchenko whitefish definitely occurs on the territory of Mongolia, but only in the Selenga River basin, from where its range extends throughout the Angara–Yenisei basin to the Nizhnyaya Tunguska.

Abstract

The Baikal Natural Territory (BNT) and Khuvsgul region have similar environmental problems. It is relevant to carry out integrated scientific studies and monitor the state of the components of the natural environment in these areas. This paper presents the results of a number of joint Russian–Mongolian projects aimed at studying and developing new methods and technologies for integrated environmental monitoring and prediction. A digital platform has been created to support scientific research and environmental monitoring. This platform makes it possible to collect, store, process, and analyze large arrays of heterogeneous spatiotemporal data and predict environmental situations using a set of mathematical and information models, services, and machine learning methods. The authors have also developed methods and web services for environmental monitoring based on the processing of Earth remote sensing (RS) data. A technology for classifying multispectral Sentinel-2 satellite images has been created that makes it possible to distinguish 12 classes of the land cover using artificial intelligence methods. A service for monitoring the state of the atmosphere over large areas has been created based on the processing of Sentinel-5P satellite data. This service makes it possible to display the concentrations of SO₂, NO₂, CO, CH₄, H₂O, O₃, formaldehydes, and aerosols in the air.

Abstract

The species composition, abundance, biomass, and productivity of zooplankton have been studied in different biotopes of Lake Dood Tsagaan in July 2022. Concerning to the qualitative composition, the lake community is characterized as cladoceran–copepod and almost equally represented by cladoceran and copepod crustaceans. Based on biomass data, dominant species have been identified in the nearshore and deepwater zones of the lake. The copepods Mixodiaptomus incrassatus (Sars), Arctodiaptomus paulseni (Sars), Arctodiaptomus anudarini Borutzky, Mesocyclops leuckarti (Claus), and Cyclops scutifer (Sars) were dominant in biomass in all biotopes of the lake. The mean zooplankton abundance in the lake was 86 300 ± 24 300 ind./m³ and biomass was 1463.7 ± 415 mg/m³. The qualitative and quantitative indicators of zooplankton have not significantly changed over the last 60 years. With respect to the quantitative characteristics of zooplankton, the trophic status of the lake can be considered as a-mesotrophic, with a medium food supply for planktophagous fishes.

Abstract

This paper discusses the results of a study of a rare natural phenomenon—the Utaat-Minchuur hot vapor anomaly located in the east of Mongolia. The first information about it appeared several centuries ago, but until now this phenomenon has not received due attention, and the question of its origin remains controversial. According to the authors, two main hypotheses are most likely. The first involves an underground coal fire. This is supported by the widespread occurrence of vapor-bearing coal deposits in the area and the constant formation of fresh depressions of ground. The second hypothesis suggests the presence of an endogenous heat source. This can be confirmed by the presence in the released gas of significant amounts of ammonia and carbon dioxide, which are characteristic of volcanic processes. In addition, effusive rocks are widespread in the vicinity of the vapor anomaly. At a distance of 8 km from the vapor anomaly, the ratio of ³He/⁴He isotopes in water samples from a self-flowing well was 1 × 10^–6, which exceeds the similar ratio in many thermal springs of Mongolia. Based on the results of drilling operations, the presence of clays with a high content of organic matter, which were heated to a temperature of more than 60°C, was revealed in the upper part of the rock formation section. To clarify the conditions for the formation of a single heat source, it is planned to conduct geophysical research and drill deep exploration wells. Thanks to the combination of balneological factors (high vapor temperature and the presence of ammonia and a number of microelements), Utaat-Minchuur is a very promising object for the development of sanatorium and resort construction. Here, patients with diseases of the musculoskeletal system, peripheral nervous system, kidneys, etc., will be able to receive treatment. The experience of balneological use of natural vapor is known in a number of resorts around the world, such as Yangantau (Russia, Republic of Bashkortostan), Obygarm (Tajikistan), and Lorderello (Italy).

Abstract

The intensively developed densely populated parts of the Baikal–Mongolian region (BMR) within the Selenga River basin and the southwestern part of the Baikal seismic zone have been selected for research. Geomorphologically, the territory is located within the Selenga Dauria, which merges with the mountain ranges of Mongolia. Earthquakes constantly occur here, and their strength varies widely, sometimes reaching catastrophic values. The high seismic potential of the region is due to the presence at a relatively short distance of seismically active zones in the north (Lake Baikal) and in the south (Mongolia) and the presence of earthquake epicenters with an energy class reaching 15. The main tectonic elements of the area are the faults that control the Meso-Cenozoic depressions. Fragments of these faults correspond to the zones of occurrence of earthquakes with a magnitude of 5.5–6.0. Therefore, the study of the seismic process, the features of the manifestation of seismicity, and the assessment of the seismic hazard of this territory are currently given special importance.The research results are aimed at developing methods for studying and predicting the seismic effects of large earthquakes in the BMR. As a result, the most probable seismic-soil models are formed for various thicknesses of loose deposits, differing in their composition and state, taking into account the depth of bedrock occurrence. The available seismogeological and geophysical information and the data obtained by us on the study of engineering and seismological conditions for the construction of a number of industrial and civil facilities are used. According to the records of the last large earthquakes by permanent seismic stations, a single initial signal was formed for the accepted level of initial seismicity. When using it for the constructed models and implementing theoretical calculations, a comparative analysis of the effect of near-surface inhomogeneities on the initial seismic signal was carried out using a set of main indicators of seismicity manifestation: seismic characteristics (accelerograms, spectra, and frequency characteristics) and their parameters (maximum accelerations and prevailing and resonant frequencies). The data presented for the prevailing varieties of soils of various conditions lead to the possibility for their use in zoning the seismic hazard of the study area.

Abstract

Global climatic changes in recent decades cause changes in the dynamics of mountain geosystems. Of interest is the response of nival-glacial inland geosystems, which is different from those in the pre-Oceanic regions. In 2013, the authors substantiated the expediency of separating the nival-glacial mountain range geosystems within the Baikal Rift Zone and Mongolian Altai into a meridional research transect, within which it is possible to establish latitudinal patterns of modern intracontinental glacier functioning. Over the past decade of ongoing studies of glacial forms within the transect, many new data have been collected and analyzed. The present article based on systematic generalizations of these materials.

The analysis of the state of mountain glaciation in the south of Eastern Siberia and Mongolia in the last decades has revealed a number of peculiarities. The deglaciation that began in the 1970s–1980s continues in all the mountain systems under consideration. It is a reaction to global climatic changes. The greatest reduction is experienced by the near-slope glaciers and flattop glaciers and to a lesser extent by the cirque ice glaciers. They have a significant volume loss due to thinning, while changes in the area of such glaciers are less significant. This is the main difference between the intracontinental glaciers and the preoceanic glaciers. In general, many nival-glacial geosystems of transitional forms are formed.

Quantitative characteristics are based on the calculation of the volume of the East Sayan glaciers measured by geophysical radar. Thus, over 120 years, the Peretolchina (northern) Glacier has decreased in length by a factor of 1.75, in area by a factor of 2.9, and in volume by a factor of 3.71. During the same period, the area of the neighboring Radde Glacier decreased from 0.43 to 0.09 km²; its thickness by 30 m; and, accordingly, its volume by 3 times. The warming of air temperature for Western Mongolia is 0.03–0.29°C/10 years and, for the Baikal region, 0.2–0.5°C/10 years. Warming of air temperatures in the ridges of the Mongolian Altai is noted up to 48° N, and southward the trend is unstable.

Abstract

The results of terrestrial landscape studies obtained in the goletzes of the Barguzin Range and Baikal Range are presented. Modern exogenous processes of relief formation, which change the structure of glacial geosystems, are considered. Profiles for further large-scale research into geosystems have been laid in the key areas. It has been revealed that, on the Barguzin Range, rocky watershed and corrie complexes and steep-slope rocky–coarse-clastic, slope–shrubby dwarf mountain pine–steppe complexes predominate. On the Baikal Ridge, the landscape structure of the key area consists of rocky, steep-slope rocky–coarse-clastic, and slope dark coniferous complexes of reduced and limited development. Using satellite images, topographic maps, and the results of ground route surveys, landscape maps of key areas were created. The basic unit of mapping at a scale of 1 : 50 000 is represented by a group of facies which is characterized by the similarity of locations and by the belonging of plant associations to one group and soil phases to one genus, which represent homogeneous natural and natural–anthropogenic geosystems of topological level. Groups of facies are differentiated with respect to the regime of moistening in different areas, the geological and structural features of rocks, the position in the relief (the relation to the altitudinal belts, steepness of slopes and exposure, and the effects of barrier shade and insolation), and the altitudinal-belt differentiation of soil and vegetation cover. It is concluded that the modern structure of goletz geosystems of Cisbaikalia is experiencing changes associated mainly with climate warming. Conditions are being created for soil formation; the overgrowth of rubbly areas with pioneer vegetation; and the expansion of dwarf mountain pine–clastic, yernik, and alder shrub habitats.

Abstract

This article considers the possibility of using probabilistic models to analyze the maximal flow discharges of rivers in order to obtain reliable calculated statistical characteristics for basins with poorly studied hydrological features. The research was performed by the example of Cisbaikalia, which is characterized by a flood regime of river flow. It is found that floods in the study area most often occur in summer (July−August), are associated with the climatic characteristics of the region, and are often destructive. The analysis of the maximal flow of rivers is based on data from the Roshydromet observation network. The series of maximal water discharges are checked for homogeneity and, in general, no disturbances in the steady state of runoff caused by climate changes are detected. A generalized distribution of extremes is proposed as the main probabilistic model; it is recommended to determine its parameters on the basis of the group analysis. The integrated approach has been applied for the first time; it combines conventional methods of hydrological calculations, which are most often used to refine the characteristics obtained for the runoff in the zone of extreme values: the apparatus for truncation of distributions; joint analysis of data; a reduction formula with the reduction of the drain modulus value not only to the area of 200 km², but also to the mean height of basins in the region; and the frequency probability method for estimation of obtained results. These methods are recommended by regulatory documents for discharge calculations and are most often individually used. The comprehensive approach described by the authors enables us to take into account the features of the runoff formation in the zone of extreme values and obtain more accurate values of characteristic quantiles of a given probability of excess for use in design on poorly studied rivers of the region.

Abstract

The efficient use of solar energy requires an accurate assessment of the incoming solar radiation. The study involves comparing the accuracy of monthly means of the global solar radiation flux from the ERA5 reanalysis database, the SYN1deg satellite-based observation database, climate reference data, and data of regression models for seven settlements in the east of Russia. The study employs two well-known regression models, including parameters of extraterrestrial solar radiation, total cloudiness, air humidity, minimum and maximum air temperature, atmospheric pressure, and a new regression model, which additionally includes parameters of low-level cloudiness and sun elevation angle. The accuracy of databases and regression models is evaluated by comparing their data with ground measurements of weather stations. The indices of the mean absolute error, root-mean-square error, and mean bias error are calculated. The comparison shows that the data of climate reference books for the period from 1937–1957 to 1980 have the smallest deviation from the estimates of the monthly mean flux of global solar radiation for 2006–2020 at most of the points discussed. The ERA5 monthly mean estimates of the global solar radiation flux are more accurate than the SYN1deg data at five of the seven points considered. The new regression model proposed in the study makes it possible to provide greater accuracy of monthly estimates of the global solar radiation flux compared to the data of SYN1deg and ERA5 for most of the points considered.