Permafrost dynamics in the north-east of European Russia at the end of the 20th century

In the major physiographic divisions of the north-east of European Russia, temperatures in the cryolithozone and the active/seasonally frozen layer were monitored during the period 1970 to 1995. Active layer depths increased on average by 11% to 15%, whereas the depths of the seasonally frozen layer decreased by 19% to 40%. The largest positive temperature increments, up to 1.2C, were characteristic for the piedmont and basement plains. Lacustrine-alluvial lowlands demonstrated oppositely directed temperature trends depending on a landform. Numerous sites with ongoing permafrost formation demonstrated negative temperature increments varying from 0.1C to 2.0C.     

Long‐distance fluid migration defines the diagenetic history of unique Ediacaran sediments in the East European Craton

The diagenetic history of the Ediacaran sedimentary rocks in the East European Craton (EEC) over the area extending from Arkhangelsk (Russia) in the north to Podolia (Ukraine) in the south was revealed by means of the XRD characterization and K–Ar dating of clay fractions, mudstone porosity measurements and organic geochemistry investigations. Mudstone porosity measurements produced direct evidence of shallow maximum burial of the Ediacaran sediments on the craton (Russia, Lithuania, Belarus, Volyn), not exceeding 1.5 km, and much deeper burial at the cratonic margin, in Podolia and Poland. In general, illitization of smectite and biomarker indices indicates more advanced diagenesis at the cratonic margin. K–Ar dating of authigenic illite–smectite and aluminoceladonite revealed the Palaeozoic age of mineral diagenesis (ca. 450–300 Ma) both on the craton and its margin, with older ages generally observed in the north. When the maximum palaeotemperatures were evaluated from illite–smectite and biomarkers, based on the calibrations from the conventional burial diagenetic sections, a major mismatch was detected for the cratonic area: 100°C–130°C from illite––smectite and tens of ^oC lower from the lipid biomarkers. This diagenetic pattern was interpreted as the result of short‐lasting (in ky scale) pulses of potassium‐bearing hot fluids migrating from the Caledonian and Variscan orogens deep in the craton interior, effectively promoting illitization in porous rocks without altering the organic matter. Analogous short pulses of fluids were responsible for numerous diagenetic phenomena, including Mississippi Valley‐Type ore deposits, in the American Midwest, in front of the Appalachians. K–Ar dating indicates that the entire Proterozoic sedimentary cover of the Great Unconformity on the EEC remained untouched by measureable post‐sedimentary changes until the early Palaeozoic, thus for over 1000 My, which is an unprecedented finding.     

Permafrost mapping of Northeast European Russia based on the period of climatic warming 1970-1995

Verdenskrigen som efterhånden i do krigførende land tok alle hjelpemidler og all intelligens i sin tjeneste og innskrenket den frie samferdsel selv for de nøitrale stater, måtte selvfølgelig legge hindringer i veien for forskningsekspedisjoner til Asia. De stoppet velikke helt op. Som vi skal se blev der også under krigen foretatt og begynt undersøkelser av denne art; men først efter krigen utviklet de sig igjen i større stil. Det synes derfor å være naturlig å velge denne verdenskatastrofe som et skille, og jeg vil i det følgende mere utførlig omtale bare de ekspedisjoner og forskninger, som vesentlig er blitt utført efter denne tid.     

Spatio-Temporal Assessment of Gully Erosion in the Zone of Intensive Agriculture in the European Part of Russia

Using the method of mapping by high resolution satellite imagery mapping, a study was made of the key areas which are located in the southern part of the forest, forest-steppe and steppe zones of Tatarstan and of Orenburg, Saratov and Voronezh oblasts. Two key indicators were determined: the gully length density and gully head density within the basins; results of the investigation were used in compiling respective maps in vector format. It is established that the density of the gully length in the basins varies over the range from 0 to 0.5 km/km² (from the absence of gullies to strong gully erosion), and the density of gully heads from 0 to 3 units/km². The slope type of gullies is dominant in all basins (about 80%), while the coastal and bottom types have approximately the same proportion (14 and 10%, respectively). Using methods of mathematical statistics we determined a high directly proportional dependence of the indicators of the contemporary gully network on the level of ploughness of the basins and the mean annual precipitation amount, and an indirectly proportional dependence on the level of sodding. An abrupt reduction in gullying indicators was determined. It was found that among the chief reasons behind an abrupt reduction in the gullies to date is a decrease of the rate of agricultural development, with an additional factor, namely, a dramatic decrease in surface runoff down the arable slopes during spring snowmelt caused by climate warming. It is concluded that that a significant part of the gully forms in the study area is currently inactive and massively passes into the balka stage.     

Reconstruction of cropland area in the European part of Tsarist Russia from 1696 to 1914 based on historical documents

Journal of Geographical Sciences - To evaluate the climatic and ecological impacts of anthropogenic activities in global change research, it is essential to reconstruct historical land use and land...     

俄罗斯人口结构研究

俄罗斯的人口数量自1994年起持续减少,人口结构也相应的发生着改变,人口问题已成为影响国家发展和民族生存的重大问题。基于人口的自然结构、地域结构和社会结构的现状,详细分析了俄罗斯人口年龄性别、城乡分布、就业、民族和移民结构等的影响因素及对社会经济发展的影响．为构建可持续发展的人口结构提供现实和理论依据。     

Risk Assessment and Disaster Management for Natural and Anthropogenically Induced Geologic Hazards: Application to the Preolkhon Region,Western Lake Baikal,Siberia, Russia

In the Western Lake Baikal, recent Baikal Rift's tectonics control the topography, seismicity, climate, geomorphology, and economy. Scarps, facets, structural terraces, horsts and grabens, and trapezoid valleys can be clearly observed. They have been generated by the recent tectonic movements along the faults and represent a serious geologic hazard. The specific geological conditions predetermine a unique variety of landscapes. Thus, the main type of the economy is tourism. However, unorganized tourism leads to the degradation of the unique landscapes. It increases risk and requires disaster management. Three criteria has been used for risk assessment: (1) degree of geologic hazard; (2) degree of landscape degradation; and (3) degree of the economy's vitality. The high ecological significance and low stability to antropogeneous pressure are typical for landscapes of the Western Lake Baikal. Thus, some special activities of disaster management should be implemented based on our investigation.     

Permafrost distribution and temperature in the Elkon Horst,Russia

The Elkon Horst is a geological structure that consists of heterogeneous strata with highly variable geocryological and temperature conditions. Gaining accurate knowledge of permafrost distribution patterns within this structure is of both scientific and practical importance. In mountainous terrain, the ground thermal regime is controlled by both surface and subsurface conditions. Surface conditions include snow cover characteristics, the presence or absence of vegetation, vegetation density, etc.. In contrast, subsurface conditions involve rock lithology or petrography, density, quantity and depth of fissures, groundwater, etc.. This article examines ground thermal regimes in various geomorphological settings based on temperature measurement data from geotechnical boreholes. The occurrence and extent of permafrost were evaluated for the entire horst area using direct and indirect methods. The maximum permafrost thickness measured in the Elkon Horst is 330 m, and the estimated maximum is 450 m at higher elevations. Thermophysical properties were determined for the major rock types, and the geothermal heat flux was estimated for the study area. The thermal conductivities were found to vary from 1.47 to 4.20 W/(m·K), and the dry bulk densities to range between 2,236 kg/m~3 and 3,235 kg/m~3. The average geothermal heat flux was estimated to be 44 mW/m~2.     

Surficial deposits on salt diapirs (Zagros Mountains and Persian Gulf Platform, Iran): Characterization, evolution, erosion and the influence on landscape morphology

The surfaces of salt diapirs in the Zagros Mountains are mostly covered by surficial deposits, which significantly affect erosion rates, salt karst evolution, land use and the density of the vegetation cover. Eleven salt diapirs were selected for the study of surficial deposits in order to cover variability in the geology, morphology and climate in a majority of the diapirs in the Zagros Mountains and Persian Gulf Platform. The chemical and mineralogical compositions of 80 selected samples were studied mainly by X-ray powder diffraction and X-ray fluorescence. Changes in salinity along selected vertical profiles were studied together with the halite and gypsum distribution. The subaerial residuum formed from minerals and rock detritus released from the dissolved rock salt is by far the most abundant material on the diapirs. Fluvial sediments derived from this type of residuum are the second most common deposits found, while submarine residuum and marine sediments have only local importance. The mineralogical/chemical composition of surficial deposits varies amongst the three end members: evaporite minerals (gypsum/anhydrite and minor halite), carbonates (dolomite and calcite) and silicates-oxides (mainly quartz, phyllosilicates, and hematite). Based on infiltration tests on different types of surficial deposits, most of the rainwater will infiltrate, while overland flow predominates on rock salt exposures. Recharge concentration and thick accumulations of fine sediment support relatively rich vegetation cover in some places and even enable local agricultural activity. The source material, diapir relief, climatic conditions and vegetation cover were found to be the main factors affecting the development and erosion of surficial deposits. A difference was found in residuum type and landscape morphology between the relatively humid NW part of the studied area and the arid Persian Gulf coast: In the NW, the medium and thick residuum seems to be stable under current climatic conditions. Large sinkholes and blind valleys with sinking streams are common. On other diapirs, the original thick residuum is undergoing erosion and the new morphology is currently represented by salt exposures and badland-like landscapes or by fields of small sinkholes developed in the thin residuum. Models for evolution of the subaerial residuum and the diapir landscape/morphology are described in this paper. While the thick residuum with vegetation has very low erosion rates, the salt exposures and thin residuum are eroded rapidly. During wet periods (e.g. early Holocene), the diapirs rose and salt glaciers expanded as the influx of salt mass was much faster compared to erosion. After the onset of an arid climate, c. 6 ka BP, the rising of the some diapir surfaces decreased or even reversed due to acceleration of erosion thanks to vegetation degradation and changes in the residuum type and thickness.     

Geomorphology of subglacial volcanoes in the Azas Plateau, the Tuva Republic, Russia

The Azas Plateau volcanic field is located in the Tuva Republic of the Russian Federation. The compositions of the Azas Plateau volcanics include low-viscosity trachybasalt and basanite. Volcanic edifices of Middle-Late Pleistocene age are widely distributed in the southeastern part of the volcanic field. There are subglacial volcanoes among the volcanic edifices, and their formation coincided with extensive ancient glaciations in the region. The dominant subglacial volcanoes in the area are tuyas. The general shapes of the tuyas (flat-tops with steep sides) are due to eruptions into meltwater lakes and confinement of ice walls, and effusive subaerial eruptions of basaltic lavas. There are also non-flat-topped subglacial volcanoes and at least one subaerial volcanic edifice in the area. Degradation appears to have modified the primary shapes of the tuya edifices, and such processes seem to include failures of over-steepened slopes, gully formation due to stream runoff and debris flows, cirque/valley glaciation, and modification by rock glaciers. The estimated thicknesses of the ice sheets covering the subglacial volcanoes during their eruptions range 300–600 m on average.     

Aeolian influences on the soils and landforms of the southern Yilgarn Craton of semi-arid, southwestern Australia

Within a landscape developed on the deeply weathered, dominantly granitic rocks of the Yilgarn Craton in southwestern Australia, there is strong evidence of prior aeolian activity. Multiple arrays of clayey saltation deposits occur as clay dunes or lunettes extending up to 5 km to the southeast of playas, and quartzose sand dunes and sheets occur in a 2-km wide band that extends 10 km southeast of an ephemeral creek line. Parabolic dunes occur within some clayey lunettes. The parallel orientation of these diverse features and the elliptical shape of the playas suggest that the winds that have created these geomorphic entities have been from the northwest. Multiple lunette arrays with up to seven members have not been previously reported in this region.There is evidence for a more widespread, but more subtle, aeolian influence on the soils. Dust deposits appear to mantle parts of the landscape and are inferred to be coeval with the clayey saltation deposits. Although these do not occur as a discrete layer, evidence includes a plume of calcareous and illitic soils southeast of the major playa, in a landscape otherwise characterised by acidic, kaolinitic soils. Similarly, the occurrence of deep sandy soils on many slopes with a southeasterly aspect may indicate the interference of topography on the transport of saltating sands during an arid climatic phase. The presence of such aeolian deposits has implications for agricultural management, mineral exploration and the interpretation of ecological gradients in similar undisturbed landscapes.Current desertification, in the form of salinization and wind erosion, has precedence in this landscape. The aeolian deposits provide a means of interpreting landscape-scale responses to previous climate change and a key to predicting possible outcomes of both desertification and future climate change. Assuming that Bowler's theory that clay dunes require an adjacent salinized playa bed to form is correct, the arrays of clayey lunettes together with vegetated former playas indicate that the landscape has undergone multiple cycles of salinization and recovery. The lunettes may thus provide a means of predicting landscape hydrological responses to the widespread removal of natural vegetation for farming. Dating of the various sequences is required to provide a time scale for these landscape processes.     

Surficial patterns of debris flow deposition on alluvial fans in Death Valley, CA using airborne laser swath mapping data

Debris flows are a common event in mountainous environments. They often possess the greatest potential for destruction of property and loss of lives in these regions. Delimiting the spatial extent of potential damage from debris flows relies on detailed studies of the location of depositional zones. Current research indicates debris flow fans have two distinct depositional zones. However, the two zones were derived from studies containing detailed analyses of only a few fans. High resolution airborne laser swath mapping (ALSM) data is used to calculate profile curvature and surface gradient on 19 debris flow fans on the eastern side of Death Valley. The relationship between these parameters is assessed to 1) identify if debris flow fans are accurately represented by two depositional zones, and 2) to assess how these terrain parameters relate to one another at the individual fan scale. The results show at least three zones of deposition exist within the sampled fans. These zones do not hold consistent when individual fan morphometry is analyzed in conjunction with localized fan surface gradients. Fans with consistently shallower gradients exhibit numerous depositional zones with more subtle changes in profile curvature. Steeper gradient fans exhibit significantly fewer zones with more pronounced local changes in profile curvature. The surface complexity of debris flow fans is evident from these analyses and must be accounted for in any type of hazard studies related to these features.     

Impact of copper smelting on lakes in the southern Ural Mountains,Russia, inferred from chironomids

Karabash (52°2 N, 60°10 E) is a copper smelting town in the southern Ural Mountains of Russia. The town is affected by sulphur dioxide emissions and deposition of metal-rich particulates from the smelter, acid drainage from old mine workings, and leachates from disused waste dumps and tailings dams. The close proximity of houses to these sources of pollution is of concern to human health and has devastated terrestrial vegetation in the environs. The environmental impact of the smelter on lakes in the area has been assessed using chironomids. Short sediment cores were taken from 16 lakes within a 50 km radius of the smelter and the composition of the chironomid fauna from the bottom of each core, representing conditions prior to the commissioning of the smelter in 1910, was compared with the present chironomid fauna in the surface sediments. Redundancy analysis (RDA) showed that changes in the chironomid fauna of most lakes were driven by trophic change, independent of the industrial activity. Lakes and ponds adjacent to the smelter and waste dumps, which directly receive contaminated waters were devoid of macro- and mesofauna and flora, but there is no evidence that other lakes have been severely impacted by smelter emissions. Local geology ensures that the lakes are well-buffered to the effects of acid deposition which will limit the bioavailability of metals in the water column and sediment.     

Satellite image based vegetation classification of a large area using limited ground reference data: a case study in the Usa Basin, north-east European Russia

Predicted global changes can be studied effectively by combining spatially explicit data sets on vegetation and other landscape properties with process models. However, detailed knowledge of the vegetation distribution of remote Arctic areas is relatively scarce. This paper shows how a mesoscale vegetation and land cover classification of a large, remote Arctic area can be conducted at a fine spatial resolution (30 m cell size) using a limited ground reference data set. The study area is the catchment of the River Usa (93 500 km²) in north-eastern European Russia. Vegetation zones in the Usa Basin range from taiga in the south to forest-tundra and tundra in the north, and to alpine in the Ural mountains in the east. Classification was done using a mosaic of spectrally adjusted Landsat TM5 images from five different dates and a semi-supervised method. Ground reference data were collected during the summers of 1998, 1999 and 2000. Accuracy of the 21-class vegetation type/land cover classification produced was tested against test points interpreted from oblique aerial photographs taken from a helicopter (logistic limitations prohibited the collection of representative ground reference data). The main vegetation types (forests, willow dominated stands and meadows, peatlands, tundra heaths, mainly unvegetated areas, and water bodies) were distinguished with relatively high accuracy: 84% of the test points were classified correctly. Spatially detailed land cover data sets like the one described here allow detailed landscape-level analysis and process modelling on many different subjects.     

The influence of Holocene tree-line advance and retreat on an arctic lake ecosystem: a multi-proxy study from Kharinei Lake,North Eastern European Russia

A consequence of predicted climate warming will be tree-line advance over large areas of the Russian tundra. Palaeolimnological techniques can be used to provide analogues of how such changes in tree-line advance and subsequent retreat affected lake ecosystems in the past. A Holocene sediment core taken from Kharinei Lake (Russia) was dated radiometrically and used for multi-proxy analyses with the aim of determining how climate and tree-line dynamics affected the productivity, community structure, carbon cycling and light regime in the lake. Pollen and macrofossil analyses were used to determine the dates of the arrival and retreat of birch and spruce forest. C:N ratios and percent loss-on-ignition were used to infer past changes in sediment organic matter. Visible-near-infrared spectroscopy and diatom analysis were used to infer past changes in lake-water carbon. Algal pigments and aquatic macrophytes were used to determine changes in lake productivity and light. Chironomids together with remains of the aquatic flora and fauna were used to provide information on past July temperature and continentality. Lake sedimentation was initiated shortly before 11,000 cal. years BP, when both chironomid- and pollen-inferred temperature reconstructions suggest higher summer temperatures than present, between 1 and 2°C warmer, and lake productivity was relatively high. A few trees were already present at this time. The spruce forest expanded at 8,000 cal. year BP remaining in the vicinity of the lake until 3,500 cal. year BP. This period coincided with a high concentration of organic material in the water column, and relatively high benthic productivity, as indicated by a high benthic: planktonic diatom ratio. After tree-line retreat, the optical transparency of the lake increased, and it became more open and exposed, and was thus subject to greater water-column mixing resulting in a higher abundance of diatom phytoplankton, especially heavily silicified Aulocoseira species. The colder climate resulted in a shorter ice-free period, the lake was less productive and there was a loss of aquatic macrophytes. Increased wind-induced mixing following forest retreat had a greater influence on the lake ecosystem than the effects of decreasing organic matter concentration and increased light penetration.     

Reindeer husbandry/hunting in Russia in the past, present and future

The dynamic state of reindeer husbandry in northern Russia during the 20th century was studied as a basis for predicting the consequences of the current drastic changes taking place there. Similar forms and methods of reindeer husbandry were used with different frequencies and effectiveness throughout the century. In the future reindeer husbandry will conform to market requirements, landscape features and national traditions. In some areas, the more sophisticated methods of management developed in conjunction with large-scale, highly productive reindeer husbanry, could be lost and a subsistence economy, including hunting, could predominate.     

历史时期分布在北京平原上的泉水与湖泊

历史时期北京平原上湖泊众多,地表泉数以百计。历史时期由于永定河冲积扇的地下潜水水位较高,在潜水溢出带周围出露数以百计的下降泉,成为平原上众多湖泊的主要水源补给,并满足城市规划、园林设计、运河漕运、游憩休闲的需要。随着现代化城市的迅速发展,永定河冲积扇的地下潜水水位迅速下降,原来分布在潜水溢出带周围的数以百计的下降泉已经全部枯竭,位于其下游许多湖泊也随之干涸消亡,北京平原地表水系被彻底改造,城市生态环境发生巨大变化。     

Rapidly growing towns in the former USSR and Russia, 1970-1993

"Using urban places of 15,000 or more inhabitants as its point of reference, this paper identifies and investigates the most rapidly growing towns and cities of the USSR during the recent intercensal periods of 1970-79 and 1979-89. Rapidly growing towns are defined as towns that grew by at least 50 percent overall for the intercensal period and at a rate of equal to or exceeding 4.1 percent annually. In addition, a category of 'doubling towns' is investigated, defined as towns that increased in population by at least 100 percent (or 6.3 percent or more annually). Special attention is devoted to the geographical aspects, economic functions, and size characteristics of the towns involved. Comparisons with 1959-70, an overall examination from 1959-89, and an update for contemporary Russia during 1989-93 also are undertaken."