M. V. Kurlenya1, V. V. Skazka1,2,3, A. V. Azarov1, A. S. Serdyukov1,4, A. V. Patutin1 1Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Sobolev Institute of Mathematics, Novosibirsk, Russia 3Novosibirsk State University, Novosibirsk, Russia 4Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Seismic monitoring, underground structures, tunnels, surface waves, rock behavior control, phase characteristics of surface waves
The authors discuss applicability of phase characteristics of surface waves in monitoring of underground openings and tunnels. The mathematical model of surface wave propagation along extended cavities is presented. The properties of the numerical solutions obtained using the model are analyzed, including the amplitude and frequency characteristics, and the phase and group velocities of the waves. It is possible to recover elastic properties of a medium using the dispersion curves of the phase velocities. The data of numerical modeling of surface wave propagation along cavities of different geometry using the method of finite spectral elements are presented. The calculated results of the axisymmetrical and three-dimensional problems of surface wave propagation along cavities are studied.
Yu. V. Osipov1,2, A. S. Voznesensky1 1National University of Science and Technology-MISIS, Moscow, Russia 2Gazprom geotekhnologii LLC, Moscow, Russia
Keywords: Bischofite, rheological properties, complex stress state, viscoelastic model, laboratory tests
Bischofite rock samples from a well at the Vologda underground gas storage are subjected to rheological tests. The time curves of deformation are plotted at different axial and lateral stresses. A viscoelastic phenomenological model is proposed, and the equation to describe these dependences is obtained. Being developed and algorithmically implemented, the experimental data interpretation procedure allows determining rheological characteristics of test rocks at different stress ratios. It is found that rheological properties of bischofite weakly depend on depth.
F. K. Nizametdinov1, V. D. Baryshnikov2, A. O. Oralbay1 1Abylkas Saginov Karaganda Technical University, Karaganda, Kazakhstan 2Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Pitwall rock mass, reference point, rock scanner, laser scanning, geological-geomechanical model, safety factor
The implementation stages of ground laser scanning of an open pit field and the obtained data processing in Maptek I-Site Studio are discussed as a case-study of Kentobe open pit mine of iron ore. The procedure of a digital geological-geomechanical model is described; the framework is a set of spatial points obtained from the laser scanning. The model enables a detailed study of geological structure of the pitwall rock mass, with regard to the structure and tectonics, as well as the physical and mechanical properties of rocks. Using the developed model, the authors estimated the pitwall stability and substantiated safe slope parameters for deeper mining.
N. Abbas1, K. Li2, N. Abbas1, R. Ali1 1Karakoram International University Gilgit, Gilgit, Pakistan 2Kunming University of Science and Technology, Kunming, China
Keywords: Uniaxial compressive strength, point load index, Schmidt hammer, rock types, correlation
To predict uniaxial compressive strength using the indirect techniques of the Schmidt hammer rebound number (N) and Point Load Index (PLI), it is required to have valid empirical equations based on rock types. This study is an attempt to address this issue by developing a model that is valid for various rock types. Three models, i.e. linear, power and quadratic, were tested on each rock type (sedimentary, ingenious and metamorphic). The highest correlation was achieved by the quadratic model. The generalized model showed the lowest correlation as against the individual models.
V. M. Seryakov, A. A. Krasnovsky
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Rock mass, roadway, support system, unstable rocks, stress concentration, stress-strain behavior, void behind support
The authors estimate stress state in the support system and in rocks nearby a roadway driven in unstable rock mass and when the voids and cavities in the roadway roof are filled with hardening foam. The calculation includes an assumption that the support system, rocks and the hardening foam deform elastically. The stress distribution in the support system is determined at different heights of the rock cavity in the roof rocks in the roadway and at different initial stress state of rocks. The zones of potentially hazardous stress concentration in the support system are identified.
S. V. Serdyukov, L. A. Rybalkin, A. N. Drobchik, V. I. Vostrikov
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Rock mass, underground opening, stress state, hydraulic fracturing, physical modeling, laboratory experiment, acoustic and seismic emission, power fluid pressure, measurement equipment
The article describes the lab-scale testing data on acoustic and seismic emission generated in hydraulic fracturing of a cement block under volumetric loading by nonequal stresses. The connection of the acoustic and seismic emission with the rate of injection of power fluid and the change in the fluid pressure in the course of the fracture initiation, growth and arrest is demonstrated. The authors recommend on improvement of receiving equipment and on using the research findings in the hydraulic fracturing control.
I. P. Shcherbakov, Kh. F. Makhmudov, A. E. Chmel'
Ioffe Institute, Russian Academy of Sciences, Saint-Petersburg, Russia
Keywords: Granite fracture, trigger effect, compression load, impact load, acoustic emission
This study focuses on an impact wave generated in a uniaxially compressed granite sample by a pendulum hammer in the direction transversal to compression. The pressure was varied from zero to a pre-destructive value. Microcracking during impacts was recorded using the method of acoustic emission (AE). The energy distribution in the time series of AE pulses followed an exponential law both in the unloaded and in the statically loaded samples. The first impacts induced local damage with a splash in AE from small cracks which, under subsequent impacts, coalesced and initiated redistribution of larger microdamages. In generation of an impact wave in a sample under pre-limiting compression, the surface of the induced main crack exceeds the area of the local damages by a few orders of magnitude, which is typical of the trigger effects which lead to large-scale fractures under external impacts at a safe-density energy.
P. V. Nikolenko, M. G. Zaitsev
National University of Science and Technology, Moscow, Russia
Keywords: Stress-strain behavior, rocks, ultrasound, coda wave, crack, control
The scope of the experimental research embraces velocities of elastic waves in rock samples before and after formation of a horizontal main crack. In undamaged samples, there is no essential change in the elastic wave velocity as the axial pressure increases from 0 to 20 MPa. The main crack having its surfaces approaching gradually leads to the increase in the elastic wave velocity. Aimed to improve sensibility of kinematic ultrasonic parameters relative to mechanical stresses, the coda wave interferometry algorithm is implemented as an analysis of times of the first arrivals of multiply scattered waves. With the mentioned algorithm, sensibility of the ultrasonic control grows considerably even in uniform samples.
S. N. Zharikov, V. A. Kutuev
Institute of Mining, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
Keywords: Rock fracture, blasting, perimeter blasting, slot raise, jointing, higher permeability zones, explosion seismics, drilling-and-blasting technology adaptation
The article describes the decision-making concept for the systemic blasting in open pit mining at structurally complex mineral deposits. The authors discuss approaches to determining allowable seismic impact in rocks having different strength characteristics.
S. V. Kovalevich1, I. V. Zyryanov1,2, V. I. Chernobay3 1Yakutniproalmaz Institute, ALROSA, Mirny, Russia 2Polytechnical Institute, Ammosov North-Eastern Federal University, Mirny, Russia 3Saint-Petersburg Mining University, Saint-Petersburg, Russia
Keywords: Mine, open pit mine, kimberlite ore, explosive rupture, detonation velocity, slot raise, grain size composition, stemming, locking arrangement, charge formation, impact wave attenuation, radial clearance, holding device, wet boreholes
The article describes semi-commercial testing of different technologies and facilities which ensure the required level of mining efficiency and quality of diamond-bearing ore. The use of the column charge explosives with radial clearance and air-split emulsion explosives allows stress state control in rock mass and reduces zones of high risk of crystal damage. The chain charge explosives appear to be a clever engineering idea for difficult mining conditions. The authors review the modern methods of drilling-and-blasting at mining sites of ALROSA.
I. E. Semenova, S. A. Zhukova, O. G. Zhuravleva
Institute of Mining, Kola Science Center, Russian Academy of Sciences, Apatity, Russia
Keywords: Geodynamic risk control, stress-strain behavior, close-spaced deposits, large-scale mining, numerical modeling, tectonic-stress rock mass, seismic monitoring
The seismic activity in undermined rock mass in a mine at the Khibiny Massif is analyzed over the period from 2008 to 2020. The influences on deformation, tensile fracturing and caving in undermined rock mass are revealed. Three zones of deformation of different nature and velocity are identified in undermined rock mass in Kirov Mine: the zone at the juncture of underground and opencast mining; the zone of overhanging rocks; the zone of two- and three-side buttress at the edges of operating deposits. It is found that mining with head-on fronts, with formation of a support pillar and with overhanging of an uncaved rock mass beam is adverse. The pillar collapses later on and deformation of the pillar-supported rock mass during breaking of the butt section on sublevels occurs in the dynamic mode with high seismic activity both in terms of the number of seismic events and their energy emission. It is found that the width of the seismic activity band and the caving pitch of the overhang depend on the height of undermined rock mass.
V. L. Gavrilov1,2, V. I. Cheskidov1, E. A. Khoyutanov2, A. V. Reznik1, N. A. Nemova1 1Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Chersky Institute of Mining of the North, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russia
Keywords: Brachysyncline-type coalfields, open pit mining, overburden rocks, internal dumping, methods, environmental safety
The authors review the application range and parameters of internal dumping in open pit mining of brachysyncline-type coalfields. Specifics of the technology is described. The factors that govern the volume of internal dumping are identified. The possible ways of increasing the volume of internal dumping are shown. The methods and means for increasing the intake capacity of internal dumps are revealed. The ecological and economic advantages of internal dumping are discussed.
V. I. Golik1,2, O. Z. Gabaraev1, A. O. Kudrya3 1North Caucasus State Technological University, Vladikavkaz, Russia 2Moscow Polytechnic University, Moscow, Russia 3Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Mineral deposit, underground mining, stress, ore, rocks, backfill, rock mass, small thickness, perimeter blasting
For structurally complex orebodies in weak zones of enclosing rock mass, a variant of the sublevel stoping technology with cemented paste backfill is proposed. On the ground of the in-situ data, the analytical relations are constructed to determine stability of artificial roof and sidewalls in stopes. It is found that backfill possessing the uniaxial compressive strength of 3 MPa preserves stability in the course of extraction of ore from adjacent stopes and in mining on the lower lying level. The recommendations on backfilling are given.
I. E. Semenova, I. M. Avetisyan, O. G. Zhuravleva, O. V. Belogorodtsev
Mining Institute, Kola Science Center, Russian Academy of Sciences, Apatity, Russia
Keywords: Tectonically-stressed rock mass, rockburst-hazardous deposits, undermined overburden rock mass failure, stress-strain behavior, seismic activity, underground mining systems
The article highlights the urgency of studying processes of deformation, displacement and collapse of undermined strata at rockburst-hazardous deposits of the Khibiny Massif with regard to geomechanical and geodynamic risks. The authors analyze failure specifics in undermined strata under the action of tectonic stresses, which consists in impeding of fracturing due to subhorizontal compression. It is found that as the thickness of ore bodies decreases and their dip angle grows at great depths, the pitch of failure increases. The problems to be solved to continue extraction of apatite-nepheline ore at minimized induced risks and at the preserved economic efficiency are listed.
B. F. Simonov, A. O. Kordubailo, A. E. Grachev, A. A. Leutkin, E. M. Pozdnyakova
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Body, piston, coil, electromagnet, expansion gap, average current, thermal conductivity, heat transfer
The authors investigate thermal processes in an electromagnetic percussion assembly of a downhole pulse vibration exciter at the rated energy mode in the naturally cooled air environment and at different methods of heat energy transmission from the coil to the body. The interrelation is found between the coil and body temperature, external cooling, duty cycle and the coil-body expansion gap when it is filled with air or oil. Based on the obtained results, the duty cycle of the vibration exciter in a well is calculated when the body of the electromagnetic percussion assembly is cooled with flow water.
L. A. Kienko1, O. V. Voronova1, S. A. Kondrat'ev2 1Khabarovsk Federal Research Center, Far East Branch, Russian Academy of Sciences, Khabarovsk, Russia 2Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Manmade materials, fine dissemination, fluorite, flotation, shielding coating, micaceous impurities, fine milling, electrolysis
The authors discuss concentration of fluorite from waste at Yaroslavskaya Mining Company. The waste accumulated in the tailings storage for the long operating period contain 11.6-20.7% of fluorite. Old tailings have specific process properties because the initial ore has experienced certain physicochemical treatment during primary processing, and owing to long storage. The package of balanced effects which ensure selective recovery of fluorite is substantiated. The obtained concentrates contain up to 95% CaF2. Production of fluorite concentrates at maximal removal of silicon dioxide, which is a strictly restricted impurity, is discussed. The ways of improving the processing circuit are proposed, and the efficiency of electrochemical treatment of the pulp fluid phase at the final stages of recleaning is proved. It is found to be possible to reduce the silicon dioxide content of the concentrates to 1.25-0.99%.
A. G. Mikhailov1, I. I. Vashlaev1, E. V. Morozov2 1Institute of Chemistry and Chemical Technology, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russia 2Kirensky Institute of Physics, Krasnoyarsk, Russia
Keywords: Mass transfer, upward capillary flow, dissolving, leaching, fluid, permeation
The article describes the studies into the process of upward mass transfer in flotation tailings with water solutions. The swift-flowing geological process is investigated using the magnetic resonance imaging. The kinetics of water-soluble minerals as well as the structure and substance transformations in the body of tailings are studied for substantiating in-situ formation of the target concentration zones at the tailings surface.
A. V. Edelev1, N. V. Yurkevich1, V. N. Gureev1,2, N. A. Mazov1 1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: Reclamation, disturbed land, dup, tailings pond, overburden, enclosing rocks, ecology, environmental damage, review
The article gives a review of scientific publications and regulatory documents connected with reclamation activities at the sites of waste storage in the mining industry in the Russian Federation. The environmental, economic and social impacts of mining are discussed. The role of reclamation in the recovery of the disturbed lands and ecosystems is illustrated, and the methods and stages of reclamation are described. The main obstacles of reclamation to be successive are revealed. It is highlighted that the spotlight should be on improvement of reclamation legislation to enhance efficiency of rehabilitation measures.
S. V. Serdyukov
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Geomechanics, hydraulic fracturing, laboratory research, equipment, LabView-based measurement equipment, data acquisition, deformation, breakdown pressure, seismic and acoustic emission
The author focuses on the measurement and recording equipment for the laboratory research of hydraulic fracturing in the conditions of rock pressure simulation. The choice of the test values, discretization intervals and observation periodicity is substantiated. The functional flows of the program code in LabView are presented. The program code ensures synchronous multi-point measurements of deformation, breakdown pressure, acoustic and seismic emission, power fluid flow rate, etc. The recommendations on selecting equipment, sensors and research findings for designing measurement and monitoring systems for geodynamic processes are given.
O.I. BAZHENOVA, A.A. CHERKASHINA
V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: Holocene, radiocarbon dating, paleosoils, fluvial phases, aeolian processes, dynamical phases of morpholithogenesis
On the basis of long-term station-based studies and soil-sedimentary sequences, a reconstruction of the morpholithogenesis of the Onon-Torey plain in the Holocene was performed. A rhythmicity of the functioning of geomorphological systems is revealed. It manifests itself in a regular change in the dynamic phases of relief formation. Characteristics of morphological, lithological and dynamic parameters of each phase are obtained. The sequence of their change in geomorphological cycles at different hierarchical levels is determined. It is shown that the largest cycle, encompassing the entire Holocene, on the Onon-Torei plain is most fully represented in sections of the valleys of the Imalka and Onon rivers. In eolian deposits, 1800-year cycles are especially clearly pronounced by periods of pedogenesis. A change in the conditions of aeolian accumulation in dune sections occurs every 260 years. In the mouths of the ravines opening into the basin of Lake Zun-Torei and the valley of the Builesan river, in the proluvial and proluvial-solifluction deposits of the Atlantic and Subatlantic periods, 130-year and intra-secular Brickner cycles are recorded, the duration of which is about 50 years. A regional scheme of alternation in the Holocene of extreme fluvial and arid phases with normal zonal dynamic phases of relief formation has been compiled. The horizons of fluvial genesis comprise the lower part of the sediments of the Holocene macrocycle. A strong manifestation of fluvial processes was noted in the Preboreal and Atlantic periods of the Holocene as well as in the transitional time from the Atlantic to the Subborial period. The normal zonal phase of matter integration in systems is evidenced by buried humus soil horizons. Soils aged about 8 and 6.4 as well as 1.2-1.4 thousand calendar years ago received regional formation. A tendency towards a reduction in the area of the lakes and an increase in the role of eolian processes against the background of a general aridization of the climate over the past 10 thousand years has been established. According to radiocarbon dating, sedimentation-accumulation rates were obtained. In general, the high dynamism of morpholithogenesis in the steppes of Central Asia is shown, which causes planation.
V.V. ZUEV1, S.L. BONDARENKO1, I.G. USTINOVA2 1Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia 2National Research Tomsk Polytechnic University, Tomsk, Russia
Keywords: UV-B radiation, total ozone content, air temperature, precipitation amount, density of annual rings, data mining
Analysis of data on the density of annual rings of conifers for the periods 1979-1993 and 1979-2006 allows us to identify patterns in the response of trees, taking into account the processes of abnormal decrease and natural recovery of total ozone content. Reconstructions of changes in total ozone content over the past 300 years along the Ural meridian according to satellite monitoring of total ozone content TEMIS (Tropospheric Emission Monitoring Internet Service project) and stem wood responses observed in data on the maximum density of annual rings of pine, spruce and larch were performed on the basis of methods of dendrochronological and spectral singular analysis, which made it possible to compare the current and past state of stratospheric ozone fields. Although changes in stratospheric ozone can play the role of a factor significantly limiting the annual growth of wood, such an approach to estimates works only in conditions of overlapping responses of trees under UV-B effects in the spectral range of 280-315 nm on stress responses from other climatic factors. Based on the results of a numerical modeling for three latitude ranges, models of maximum annual density were calculated in terms of changes in total ozone content and reconstructions of their past changes were given. The aridity of the climate and its cyclicity increase the stress effect of the ozonosphere on vegetation associated with an increase in UV-B radiation, and allow us to differentiate the responses of trees according to stressors by statistical methods. Reconstructions of total ozone content from April to September for the Ural meridian show that the level of total ozone content has not yet reached the previous historical values.
N.V. PODNEBESNYKH
Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Tomsk, Russia
Keywords: surface temperature, atmospheric pressure, precipitation, characteristics of cyclones and anticyclones, Siberia
The study is made of the changes in climatic characteristics, such as air temperature, atmospheric pressure and precipitation and their relationship with the large-scale atmospheric circulation over Siberia for the climatically significant time interval 1979-2018. The study area was limited to 50-70° N and 60-110° E. In calculating the series of territory-averaged values of surface temperature, atmospheric pressure and average precipitation, daily observational data from NOAA-GSOD were used. The characteristics of baric formations of cyclones and anticyclones were determined on the basis of surface synoptic maps for standard meteorological periods. It was found that by the end of the study period the trend in surface temperature and precipitation is positive, and the trend in atmospheric pressure is negative. The trend in characteristics of baric formations, such as the number of cyclones and anticyclones, is positive, as is the pressure trend in the centers of anticyclones. On the contrary, the pressure trend in the centers of cyclones is negative, as is the trend in the duration of the impact of cyclones and anticyclones. It is shown that these trends underwent the most dramatic changes during 2012-2018, with a change of sign of the trend in pressure in the centers of anticyclones. Taking into consideration the close relationship between climatic characteristics and large-scale atmospheric circulation it can be suggested that the warming in Siberia before 2012 was due to a weakening of anticyclonic activity, and after 2012 it was due to an increase in cyclonic activity.
A.V. POZDNYAKOV, YU.S. PUPYSHEV
Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, Tomsk,Russia
Keywords: Chuya-Kurai basin, ultra-high-pressure ice-dam, abrasion terrace, ablation, thermal erosion, paleolake
New results from studying the possible mechanisms of formation and degradation of the Chuya-Kurai ultra-high-pressure ice-dammed lake are presented. The conclusions are based on the analysis of the climatic hydrothermal regime which governs the development of the processes of self-freezing of the ice-dam and its subsequent degradation. According to updated data, at the maximum filling to the absolute level of 2133 m, the depth of the paleolake was 657 m, the volume of water was 753 km3, the water area was 3054 km2, and the maximum hydrostatic pressure was 65 kg/cm2 (6.37 MPa/cm2). The drainage of the lake basin was accompanied by the formation of 200 abrasive-accumulative terraces on the slopes of the basins in the height range of 1530-2133 m. A quantitative assessment of the formation time of one abrasive terrace in periglacial conditions is made as well as estimating the duration of the action of wind-wave processes for the development of abrasion: it did not exceed 90 days of a warm season. The water layers drained during the year through the thermal erosion channels of the ice dam were determined by the difference in the heights of the abrasive terraces. The duration of the existence of an ice-dammed lake has been clarified. The study used current quantitative data on measuring the average annual flow rate of the Chuya River at the nearest Chagan-Uzun hydrological post. Calculations have shown that the filling of the lake basin to the maximum volume of water of 753 km3 (taking into account the water accumulating in the ice dam, 68 km3 (total V = 821 km3)) was carried out for 5324 years. The duration of water discharge, determined by the number of abrasion terraces, was no more than 200 years. The frequency of retrogression of the lake level, equal to 20 years, has been revealed. Apparently, it was caused by climatic fluctuations: changes in cooling and warming.
a:2:{s:4:"TYPE";s:4:"HTML";s:4:"TEXT";s:103:"P.S. BORODAVKO1, M.A. MEL’NIK1, E.S. VOLKOVA1, O. DEMBEREL2";} 1Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia 2Khovd State University, Khovd, Mongolia
Keywords: Western Mongolia, glaciation, GIS, climate, water resources, lakes
Based on field expedition research and analysis of high-resolution polychronous satellite imagery data carried out in AlWaRes GIS environment, the latest data on the modern state of lake-glacial resources of Tsambagarav Ridge (Western Mongolia, Mongolian Altai), and their changes since the maximum of the Little Ice Age of the 17th-19th centuries were obtained. It was found that at the maximum transgressive stage of the Little Ice Age, with 3D topography of mountain-glacial basins taken into account, the glaciation of the ridge covered 99.1 km2, and the total volume of glaciers reached 4.72 km3. The subsequent climate changes during the post-maximum phase of the Little Ice Age entailed a spatial transformation of the nival-glacial belt of the ridge, implying a progressive reduction in the size of the glaciation and the uplifting of its lower vertical limits. By August 2020, the total glaciation area of Tsambagarav Ridge decreased to 65.21 km2 and ice reserves decreased to 2.98 km3. A statistical analysis of the mean annual air temperature of the northern regions of Western Mongolia over a half-century period showed a steady positive trend. A rise of annual air temperature was also accompanied by a decrease in temperature during the ablation period (June-August). In the modern deglaciation belt of the ridge, eight glacial lakes have appeared with a total water area of 0.34 km2 and a water reserve of 1 260 000 t. Analysis of satellite imagery from 1966 to 2020 shows that most of them have formed in the last half a century and are confined to the pre-glacial margins of modern glaciers. Dependencies developed in the course of the study are used to calculate the indicators of intrastructural redistribution of water storage from glacial to limnic systems from the maximum of the Little Ice Age to 2020.
G.V. VASILIEVA, S.N. GOROSHKEVICH
Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia
Keywords: edificator species, natural hybridization, introgression, Eastern Siberia, hybrid zones, intraspecific diversity
This paper presents the results of long-term expeditions which were aimed to study the occurrence of natural hybrids between Siberian stone pine (Pinus sibirica Du Tour) and Siberian dwarf pine (P. pumila (Pall.) Regel)). It was found that the ranges of these species are the most extensive among the five-needle pines, and they are located mainly in northern Asia. The eastern part of the Siberian stone pine range and the western part of the Siberian dwarf pine range overlap. Where both species grow together and the conditions for their cross-pollination are favorable, hybrids F1 are formed. It is shown that hybrids do not withstand competition with upright trees in phytocenoses typical for Siberian stone pine and are often damaged by snow piling. In phytocenoses typical for Siberian dwarf pine, hybrids show good growth, but are damaged due to frost weathering. It was found that the most favorable locations for hybrids are open sunlit areas where they form a balanced symmetrical crown and have abundant cone-bearing, but such locations are scarce. It is shown that the hybrid zone is characterized by mosaic structure, and in the northeastern and southwestern parts hybridization transforms into introgression. In the northeastern part of the hybrid zone, which coincides with the northeastern border of the Siberian stone pine range, hybridization has led to the replacement of Siberian stone pine by cryptic hybrids with the morphology of this species and mitochondrial DNA of Siberian dwarf pine, which are obviously more adapted to local conditions. In addition, it was found that hybrids growing in the south of Tomsk oblast are resistant to local climate and pests to the same extent as are parental species, and their unusual crown form, intermediate relative to the species, allows us to consider hybrids as an additional source of plant material for use in breeding work.
T.A. Blyakharchuk1,2, M.A. Pupysheva2 1Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences, Tomsk,Russia 2Tomsk State University, Tomsk,Russia
Keywords: paleofires, microcharcoal, lacustrine sediments, climate, pollen, Holocene
This article compares three methods of representing micro-charcoal analysis data for studying the thousand-year history of paleofires by using, as an example, microcharcoal data from the bottom sediments of Lake Uzunkol (Ulagan Plateau, Central Altai). The advantages of using the CC index of absolute concentration of microcharcoal per 1 cm3 (Charcoal Concentration) and the CI index for calculating the annual accumulation of microcharcoal per 1 cm2 unit area (Charcoal Influx) in lake sediment samples in comparison with data on absolute counts of microcharcoal are proved. The results from applying the CC and CI indexes of microcharcoal to paleocharcoal data from bottom sediments of Lake Uzunkol, covering the time interval from the Late Glacial (17 000 cal. yr BP) till the present, are analyzed. The application of these indexes removes the artificial effect of the increased abundance of microcharcoal in the case of low pollen productivity of steppe landscapes. Results from studying paleomicrocharcoal in bottom sediments of Lake Uzunkol by using the three methods showed that natural fires in Central Altai were most intense in the Holocene during the transitional, unstable climatic period 9500-9000 cal. yr BP, when one type of landscape (steppe) was replaced by another type (forest). That is, forest-steppe landscapes were the most prone to natural fires in the past. By using the CI index, it was found that the development of ancient cultures in the Altai region was accompanied by a general increase in the concentration and accumulation of microcharcoal in lacustrine sediments, starting from 4500 cal. yr BP. A dramatic increase in the concentration and annual accumulation of microcharcoal occurred after 1700 cal. yr BP, which could be caused by an increase in population density in this region of Altai.
V.V. KRAVCHENKO
V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: river channels, vertical deformations, hydrometric data, calculation methods, relationships between water flow rates and levels, lowest elevations of channels
Methods for calculating vertical channel deformations based on hydrometric observations at the network of Roshydromet posts are considered. A method based on the relationship between water flow rates and levels is evaluated. It is concluded that the use of this method causes a number of serious difficulties and contradictions which do not allow its use in mass calculations. A method for assessing deformations based on using the lowest elevations of the channel is proposed. These marks are calculated from measurements of the channel simultaneously with the regular determination of water flow rates. The method was tested at 41 stations with a catchment area from 116 to 186 000 km2 in the basins of the Angara, Upper Lena, Vitim, and Lake Baikal. The data were used for the entire observation period, with a duration of 35 to 80 years from 1943 to 2017. Vertical deformations are noted at all posts without exception. Their characteristic amplitude for the observation period is 50-150 cm. At one quarter of the posts, this value reaches 150-300 cm. The trend of deformations is multidirectional. In 41 and 39 % of cases, scouring and alluvium were observed, respectively. At the other posts, the trend is not pronounced. The calculations and the examples of their interpretation show the ability of the approach described to reveal various features of the process of vertical deformation of river beds. In particular, on its basis, it is concluded that there is a relationship between deformations and water flow rates when the same water flow rate on small rivers can produce tens of times more work of deformation of the channel bed than on large rivers.
H. MORALES-IGLESIAS1, A.G. PRIEGO-SANTANDER2, E. DÍAZ-NIGENDA1, M.A. ALATORRE-IBARGÜENGOITIA1 1Instituto de Investigación en Gestión de Riesgos y Cambio Climático, Universidad de Ciencias y Artes de Chiapas, Tuxtla Gutiérrez, Mexico 2Universidad Nacional Autónoma de México, Morelia Michoacán, Mexico
Keywords: geocomplex, biodiversity, natural landscape, geomorphology, landscape analysis, sustainable use of the territory
This research has identified the landscapes in Chiapas State (Mexico) with the best natural conditions by using the theoretical-methodological principles of complex physical geography. To achieve this goal, the biodiversity was assessed by calculating the number of vascular plant species for each landscape unit and correlated with the results of previous research regarding landscape diversity and anthropization of vegetation cover. The results indicate that the highest levels of biodiversity correspond to the predominant and recurring landscapes. These geographical relationships indicate the influence of the geomorphological component on the distribution of biodiversity, which was quantitatively validated via two statistical correlations. It was found that the complexes of summits, hillslopes, and gullies in mountain landscapes of tectonic-karstic, tectonic-accumulative and tectonic-intrusive origin, in temperate, semi-warm humid to subhumid, warm humid, and warm subhumid climates, located in the physical-geographical regions of Lacandona Mountains, Southern Mountains of Chiapas, and Western Mountains of Chiapas, all have the most preserved physical-geographical landscapes. In recent years, however, geocomplexes have been impacted by society, which is particularly evident in the Northern Mountains of the Chiapas region. The results of this research are an important contribution to the land-use planning processes because they make it possible to objectively establish environmental policies in Chiapas. For instance, this research provides the geographic basis for modifying or promoting new natural protected areas.
T.I. ZABORTSEVA, A.R. BATUEV, V.M. PARFENOV
V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: socio-economic geography, natural resource studies, taiga territories, integrated development, systematic approach, thematic mapping
A brief review of research and organizational and teaching activities of a famous geographer Yuri Petrovich Mikhailov, whose creative life activity is connected with the V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences (1961-2010). The fields of his scientific interests are considered: theory and methods of socio-economic geography, problems of nature management, peculiarities of the development of the domestic agrarian sector and rural areas, and integrated development of the taiga territories of Russia. A special place in Yu.P. Mikhailov’s scientific work is occupied by the issues related to the study, assessment and mapping of natural resources as well as geographical expert examination of major projects, the study of processes associated with the transformation of the habitat and the prediction of the consequences, and the protection and reproduction of the natural environment. It is explicitly pointed out that the wishers and message of Yu.P. Mikhailov’s scientific work to future generations of geographers imply their commitment to a system approach in geography. Presented is an extensive geography covered by the scientist’s research: Leningrad oblast, Crimea (subjects-polygons of his first field work) and, later, the territories of Siberia and the Far East. Qualitative and quantitative parameters of his publication activity and achievements in research and organizational activities are reflected. It is emphasized that the works of Yuri Petrovich Mikhaylov have an enduring theoretical and methodological, constructive and ideological significance.
I.V. BYCHKOV1,2, I.I. ORLOVA1,2 1Matrosov Institute for System Dynamics and Control Theory, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 2Russia Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Scientific Council of the Siberian Branch of the Russian Academy of Sciences on Lake Baikal Problems, norm formation procedure, permissible impact, Lake Baikal level regulation modes, scientific support
The problem of regulation of the lake level, the operating modes of the Irkutsk hydroelectric power station and its impact on the Baikal ecosystem is a subject of active discussion at various public and scientific levels in Russia and internationally. By the decision of the Presidium of the Russian Academy of Sciences No. 115 of June 22, 2021, the Scientific Council of the Siberian Branch of the Russian Academy of Sciences (SB RAS) on the problems of Lake Baikal was tasked to consider scientific problems, the results of research as well as draft regulations on Lake Baikal conservation on the basis of open, uncompromising and professional discussion, pursuing the goals of Lake Baikal conservation in conditions of ensuring the rights of the region’s residents. Presented is an overview of the efforts made by SB RAS and the Scientific Council of SB RAS on Lake Baikal Problems in 2021, the norm formation procedure as regards the permissible impact on the lake ecosystem and the achievement of coordinated positions of scientists concerning the issues of joint definition of requirements for discharges into Baikal and presumption of danger of anthropogenic impact on the ecosystem. In the work on studying the influence of the Lake Baikal level regulation modes on the condition of its ecosystem, SB RAS performs the functions of the leading organization in relation to scientific institutes under the scientific and methodological guidance of SB RAS, educational institutions and research institutes of federal departments. Measures are suggested in this paper to further develop the powers of SB RAS to carry out integrated scientific research, and the use of the “only supplier” institute represented by SB RAS is substantiated to provide scientific support of the measures for the conservation of Lake Baikal.
I.V. BYCHKOV1, V.M. NIKITIN2 1Matrosov Institute for System Dynamics and Control Theory, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 2Melentiev Energy Systems Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: water resources, level fluctuation, water level conditions, flow rate of the Irkutsk HPP, water balance, environmental requirements
The problems of Lake Baikal level regulation, hydrological conditions and characteristics of changes in the level regime of the lake in recent years, including the low-water (2014-2017) and high-water (2020-2021) periods, and also the changes in the legislative framework caused by them are considered. A historical overview of the development of the water resource management rules of the Irkutsk reservoir (Lake Baikal) for the period from the end of the construction of the Irkutsk HPP to the present is given. The main problems that arise in the regulation of the lake level in different periods of water level in the Baikal basin, and the contradictions of the existing WRMRs are analyzed. The reasons and prerequisites for the adoption of Decree No. 234 and temporary Decrees of the Government of the Russian Federation on the regulation of the lake level are pointed out. The results of individual, previously performed studies on this issue are presented. Particular attention is paid to the analysis of the proposed “environmental requirements” that must be taken into account when regulating the level of the lake. The reasons that do not allow their practical application are noted. The ideas that have developed in recent years about the causes of emerging problems and ways to solve them are considered. The most urgent and still unresolved issues related to the level regulation are highlighted. To form scientifically based and practicable principles for regulating the level of Lake Baikal in different water level conditions, taking into account modern environmental, socio-economic and water management requirements and restrictions, it is reasonable to carry out a comprehensive research work. The purpose, main tasks and expected results of research work on the topic “The impact of changes in the water level in Lake Baikal on the state of the lake ecosystem, the determination of damage to economic facilities and infrastructure of the coastal territory of the Republic of Buryatia and Irkutsk oblast, depending on the levels of the lake and discharges from the Irkutsk HPP” are outlined. The work has been carried out within the framework of the national project “Ecology” (“Preservation of Lake Baikal” subproject) by the institutes of the Siberian Branch of the Russian Academy of Sciences, the Ministry of Science and Higher Education of the Russian Federation, the Federal Service for Hydrometeorology and Environmental Monitoring, and the Federal Agency for Fishery.
A.K. TULOKHONOV, A.S. MIKHEEVA, S.N. AYUSHEEVA, T.B. BARDAKHANOVA, A.N. BESHENTSEV, L.B.-Zh. MAKSANOVA
Baikal Institute of Nature Management, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, Russia
Keywords: damage, direct losses, lost profits, mapping, legal acts
An analysis is made and methodological approaches are suggested to assess the economic, social and environmental consequences of flooding and waterlogging of territories confined to the water area of Lake Baikal. The concept of economic assessment of the impact of the level regime of a water body on natural and economic complexes and the population is generalized. The factors influencing the valuation of damage are identified, and the main characteristics of the consequences of the negative impact of water are presented. The necessity of updating the methodology for assessing the likely damage from the negative impact of water and assessing the effectiveness of the implementation of preventive water management measures in terms of certain categories of damage is shown. A technique for geoinformation mapping of the negative impact of the level regime of Lake Baikal on natural and socio-economic sites is suggested. The cartographic database contains a vector layer of land boundaries and an attribute table. On the basis of direct counting methods, local damages are calculated by taking into account actual losses based on standard specific indicators and prevailing market prices for products, lost profits, and valuation of ecosystem services. The methods of transport and recreational costs are used, which assess the willingness to pay for environmental benefits in accordance with information on time and cost expenditures when visiting a recreational facility. An analysis of the regulatory framework for assessing socio-economic risks in case of changes in the water level in Lake Baikal is made by using the territory of Buryatia as an example. A grouping of socio-economic systems of coastal territories was carried out according to vulnerability criteria.
V.M. NIKITIN1, N.V. ABASOV1, E.N. OSIPCHUK1, T.V. BEREZHNYKH1, V.Yu. GEORGIEVSKY2, A.V. IZMAILOVA2, T.G. MOLCHANOVA2, T.V. FUKSOVA2 1Melentiev Energy Systems Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 2State Hydrological Institute, St. Petersburg, Russia
Keywords: water balance, surface inflow, useful inflows, precipitation, evaporation, discharge through the HPP, climatic changes
Presented are the results from investigating changes in the water balance components of Lake Baikal for the operation period of the Irkutsk HPP (1960-2020) on the basis of analyzing the long-term dynamics, including the surface inflow, discharge through the Irkutsk HPP, precipitation on the lake surface, and evaporation from the lake surface in monthly, quarterly and yearly resolutions. The surface inflow constitutes the main component of the inflow portion of the water balance and is determined from observational data obtained at 32 posts on the rivers flowing into the lake and from calculated values of the inflow from the part of the catchment which is not covered by hydrometric observations. It is pointed out that the share of the large rivers (Selenga, Upper Angara, and Barguzin) accounts for about two-thirds of the total surface (river) inflow. Over the last several decades, the proportion of the inflow via the Selenga river has decreased by 20 % against the preceding period. An analysis of the long-term changes in the river and useful inflows showed the existence of two periods with low water: 1976-1981 and 1996-2017 as well as two periods with abundance of water: 1960-1975 and 1982-1995, and an increase in the inflow since 2018. A comparison is made of the water balance components for two periods of equal duration: 1971-1995 and 1996-2020. A disturbance of the uniformity is observed for the discharges through the Irkutsk HPP. The study revealed an increase in mean annual temperature by 1-2 °C and a decrease in atmospheric precipitation almost throughout the lake drainage basin. The annual values of precipitation after 1996, compared with the preceding period, decreased throughout the territory of the lake drainage basin by 30-60 mm. Using two extreme periods of low water (2014-2017 and 1976-1981) we consider the role of the Irkutsk HPP in the regulation of the level regime of the lake.
V.N. SINYUKOVICH
Limnological Institute, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: water level, regulation, extremes, seasonal increase/decrease, optimal regime, overload
Based on regular observations of the water-level regime of Lake Baikal, we studied the characteristics of interannual fluctuations in the level of the water body under natural conditions and in the period of the regulated lake. There were differences in the onset of the seasonal water level extremes, the range of its fluctuations and the rate of its increase/decrease in different months. The main differences in the characteristics of the water-level regime of the lake were associated with forcing and anomalous periods in terms of water content. In the forcing years, the interannual range of fluctuations in the water level increased by 20-25 %, and the dates of autumn water filling of the lake delayed up to 30-40 days. The intensity of increase in the water level after the regulation of the lake remained within 6-7 mm/day but reached 18 mm/day in August 1973. The restructuring of interannual fluctuations in the surface water inflow to the lake caused by climate change could also affect the changes in individual indicators of the water-level regime of Lake Baikal. The assumption about the adaptability of Baikal organisms to the water-level regime of the lake, which existed under natural conditions, included concerns about the need to preserve its main parameters in the years after regulation of the lake. Some problems are pointed out regarding the compliance with the rules for the use of the Baikal water resources and maintenance the optimal water-level regime of the lake for its aquatic biological resources. The major problems are the new restrictions of the discharge through the Irkutsk Hydroelectric Power Station both in terms of non-flooding of economic facilities in the downstream of the hydroelectric complex and in terms of ensuring uninterrupted water and heat supply to the cities located there. Also, there are restrictions of the upper limit water level of Lake Baikal in the zone of variable backwater. Moreover, the existing legislation concerning regulation of the lake runoff and its water level needs to be improved.
In conditions of extremely low- and high-water years, the boundary conditions for the level regime of Lake Baikal as established by resolution of the RF Government No. 234 of 3.26.2001 (within 456-457 m according to the Pacific Elevation System, PES) cannot be complied with objectively for a number of reasons. An objective assessment of the influence of the water level on the socio-economic and ecological state of the coastal territories requires a modeling of the position of the shoreline with its different levels. On the basis of an analytical overview of publications, we compiled a list of settlements located along the eastern coast of Lake Baikal which are experiencing the negative influence of water level fluctuations. Information regarding the existence of unique natural sites and a well-developed touristic-recreational infrastructure was also included. Field and laboratory work was made on modeling the characteristics of the topography of model territories involving high-precision aerial photographic imaging from an unmanned aerial vehicle, and the creation of orthophotomaps and digital elevation models. Flood zones of the coastal areas of Lake Baikal were constructed for extremely high levels of water surface (457.25, 457.50, and 457.85 m PES). We compiled the list of natural sites within the flood zone: nesting sites of rare species of the avifauna and rare and endangered plant species included in the Red Data Books of the Republic of Buryatia and Russia. The possible negative effect on the ichthyofauna of the aquatic ecosystem of the Posol’skii Sor Bay is pointed out. The negative consequences of the high water level in Lake Baikal also imply coastal forest dieback due to abrasion processes affecting the shores. The results obtained by modeling efforts can serve as a basis for calculating the potential damage to economic and ecological systems of model territories.
This article discusses the main methods for assessing the impact of dynamic changes in hydrological conditions of the lake on the natural environment of its coast. A brief component-wise analysis is made of the current state of the natural conditions of the coastal territory with a focus on the formation of the analytical physical-geographical basis for assessing the ecological consequences under various scenarios of changes of the Lake Baikal level. The territories vulnerable to the occurrence and development of unfavorable natural processes, which are most susceptible to fluctuations of the lake water level, have been identified Baikal. It is shown that the estuarine zones of tributaries and low coastal areas, which are the habitats of endemic and red-book biota species, are most susceptible to the negative influence of fluctuations in the lake level. The study of the natural components of the coast: geomorphological elements, soils, vegetation, animal world and landscapes in general has been carried out on the basis of published data and the results of previous and current research by the authors. It is concluded that the influence of the lake’s hydrological regime on the adjacent territory has not been adequately explored to date.
A.M. PLYUSNIN, E.G. PERYAZEVA
Dobretsov Geologrical Institute, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, Russia
Keywords: abrasive and accumulative processes, landslides, permafrost processes, flooding, waterlogging of lands
This article considers the reasons for the intensive destruction of the eastern shore of Lake Baikal during the rise of its level, and gives quantitative characteristics of the wave abrasive activity. It is shown that the most active development of abrasion occurred in 1962, 1964, 1971, 1973, 1983-1985, 1988, and 1990-1994 when the highest rise in the water level in Lake Baikal was observed. Due to the rise of the level in the estuaries of rivers and the coastal part of the lake, the direction and intensity of lateral currents have altered, lateral erosion has intensified, and deposit accumulation conditions have changed. It is shown that sand material washed away from the shores does almost not form beach deposits, because it is moved by currents along the coast. Engineering structures in settlements remain unprotected from the wave impact and continue to collapse. Their operation requires annual repairs. It is shown that when the lake level rises, due to an intensification of flooding, tens of square kilometers of agricultural land will be withdrawn from economic circulation, and motor roads and power transmission lines will be affected. The article highlights the areas of the most intensive development of various negative phenomena during the rise of the water level where additional research is required to determine the damage caused to nature and to engineering structures.
a:2:{s:4:"TEXT";s:27:"E.A. IL’ICHEVA, M.V. PAVLOV";s:4:"TYPE";s:4:"text";}
V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Keywords: estuarine system, morphostructure, order of the river system, coast, near-shore zone
The natural preconditions for the development of various morphogenetic types of estuarine systems of the main tributaries of Baikal are considered. The objective of this study was to examine the estuarine areas and adjacent shores of the lake, the development of which is largely due to fluctuations in the current level of the lake-reservoir. The river mouth systems are represented by a complex of subaerial and subaquatic accumulative-erosive landforms and their sediments formed by a river and the lake within the river mouth at the present stage. Within the estuarine areas, there is a wider range of landforms created during the more ancient stages of interaction in the river - sea system. The main recent factors in the development of the estuarine systems of Baikal include fluctuations in the level of the reservoir, wave activity, alongshore currents, and the associated sediment transport and river runoff. The preconditions for the formation and development of various morphogenetic types of estuarine systems are the geological and tectonic features of the coast, which in turn are predetermined by the positive and negative morphostructural elements of the Baikal rift zone as well as by the layer of loose deposits. In addition, tectonic structures determine the nature of the interaction of river flows at the contact with the waters of the receiving reservoir in conditions of deep or shallow near-shore zone. The relationship between the development of morphogenetic varieties of river mouths and the morphostructural features of the marginal elements of the Baikal rift zone, the geometric pattern of the coasts, the slopes of the seashore, and also the ordinal structure of the river system has been determined. The estuarine systems of Baikal undergo multidirectional changes during periods of different water levels, which correspond to the formation or degradation of coastal landforms and channel deformations in the lower reaches of tributaries. An integrated scheme has been developed, which combines the dynamic and morphogenetic classifications of coasts and the types of mouth for the Baikal tributaries. A schematic map of the morphogenetic types of estuaries and the geological and tectonic preconditions for their formation is presented.
