共查询到20条相似文献，搜索用时 62 毫秒
1.
L. M. Sorokovikova G. I. Popovskaya I. V. Tomberg N. V. Bashenkhaeva 《Water Resources》2009,36(4):443-452
Specific features of the concentration dynamics of biogenic substances, organic C, and phytoplankton in the lower reaches of the Selenga and its delta branch are identified. The quantitative and qualitative changes in these components are demonstrated for the conditions of extremely low water abundance. High correlation was shown to exist between variations of the concentrations of nitrate N, mineral P, and phytoplankton biomass. 相似文献
2.
L. M. Sorokovikova G. I. Popovskaya V. N. Sinyukovich I. V. Tomberg N. V. Bashenkhaeva N. A. Tashlykova 《Water Resources》2006,33(3):321-328
Results of comprehensive studies that were carried out during freezing period in the lower reaches of the Selenga River and in water bodies located within its delta revealed peculiarities of water chemistry, phytoplankton species composition, and the characteristic features of alga development. Quantitative assessment of algae is also presented. 相似文献
3.
Averaged many-year measurement data on the concentrations of mineral forms of biogenic elements are analyzed, and their total concentrations in the rivers of Selenga, Chikoi, Khilok, Uda, Dzhida, and Temnik are evaluated. The monthly variations of the concentrations of major biogenic substances are characterized, and their ratios within a year are determined. Characteristics of river water runoff and biogenic substance concentrations are used to evaluate their within-year discharge by rivers. Characteristic variations in the ratios between the total and mineral forms of biogenic elements discharged by rivers have been revealed. It is established that the share of mineral components in the total input into the Selenga delta Ntot and Ptot are 82 and 22%, respectively. 相似文献
4.
The gas regime and active reaction of water in Selenga basin rivers are analyzed. It is shown that, in the lower reaches of the Selenga and Uda rivers, which experience the highest anthropogenic impact, the minimal values of hydrogen index were recorded in under-ice period, while in the rivers of Chikoi, Khilok, Dzhida, and Temnik, during spring flood and summer freshets. The concentrations of organic substances are heterogeneous and vary widely under the effect of matter input with major tributaries and wastewater discharge from GOS. It has been established that the concentrations of readily oxidizable organic substances in 28–33% of the taken samples are above the established standards on maximal allowable concentrations in the period of open river channels. In spring and autumn, the organic matter in the rivers of the basin is mostly represented by soil terrigenous material. 相似文献
5.
Principal-Component Method is used to identify the major factors governing the long-term variations of water chemistry in
the transboundary rivers of Selenga and Kiran. Their preliminary interpretation was made. Water chemistry formation in both
large (Selenga) and small (Kiran) rivers is shown to be mostly governed by natural-climatic factors. Thus, an increase in
water abundance has a dual effect on water chemistry: on the one hand, water is enriched with substances increasingly entering
it because of the more intense erosion and dissolution of solid rocks, and, on the other hand, the concentrations of chemicals
of anthropogenic origin decrease because of their greater dilution. A conclusion was made regarding a relationship between
a positive trend in water temperature and an increase in the concentration of chlorine ion in water. A preliminary estimate
is given to the effect of municipal and industrial wastes, as well as surface and subsurface waters of various genesis on
long-term variations of river water chemistry. Trends in changes in water chemistry were studied by using approximations of
long-term series of the variables that determine the interpretation of principal factors with the help of a slow trend by
“caterpillar” method. 相似文献
6.
Daniel Karthe Sergey Chalov Vsevolod Moreido Margarita Pashkina Anna Romanchenko Gunsmaa Batbayar Andrei Kalugin Katja Westphal Marcus Malsy Martina Flörke 《Water Resources》2017,44(3):399-416
The Selenga River is the main artery feeding Lake Baikal. It has a catchment of ~450000 km² in the boundary region between Northern Mongolia and Southern Siberia. Climate, land use and dynamic socioeconomic changes go along with rising water abstractions and contaminant loads originating from mining sites and urban wastewater. In the future, these pressures might have negative impacts on the ecosystems of Lake Baikal and the Selenga River Delta, which is an important wetland region in itself and forms the last geobiochemical barrier before the Selenga drains into Lake Baikal. The following study aims to assess current trends in hydrology and water quality in the Selenga-Baikal basin, identify their drivers and to set up models (WaterGAP3 framework and ECOMAG) for the prediction of future changes. Of particular relevance for hydrological and water quality changes in the recent past were climate and land use trends as well as contaminant influx from mining areas and urban settlements. In the near future, additional hydrological modifications due to the construction of dams and abstractions/water diversions from the Selenga’s Mongolian tributaries could lead to additional alterations. 相似文献
7.
The intra-annual and spatial dynamics of the major ion concentrations and TDS of Selenga River water (Russian segment) was analyzed. Water salinity was found to decrease in the open-channel period and in the downstream direction. The anthropogenic effect manifests itself not only in an increase in the concentration of reactive components with growing volume of discharged wastewaters, but also in changes in its annual distribution. 相似文献
8.
N. L. Frolova P. A. Belyakova V. Yu. Grigor’ev A. A. Sazonov L. V. Zotov 《Water Resources》2017,44(3):359-371
Many-year variations of river runoff in the Selenga basin are analyzed along with precipitation, potential evapotranspiration, and basin water storages. Data of ground-based (1932–2015) and satellite observations, as well as the analysis of literature data suggest the presence of within-century cycles in the series of annual and minimum runoff. Compared with 1934–1975, the Selenga Basin shows a general tendency toward a decrease in the maximum (by 5–35%) and mean annual (up to 15%) runoff at an increase in the minimum runoff (by 30%), a decrease in the mean annual precipitation (by 12%), and an increase in potential evapotranspiration by 4% against the background of a decrease in evaporation because of lesser soil moisture content and an increase in moisture losses for infiltration because of permafrost degradation. The observed changes in water balance may have unfavorable environmental effects. 相似文献
9.
Bioassay methods are used to assess the toxicity of bottom sediments in the main watercourses of the Selenga River basin and Lake Orog in Mongolia. Toxic bottom sediments are found in a brook in the region of the Erdenet Mining and Concentration Complex, as well as in the Eroo and Bukhlyn rivers, which experience the effect of intense gold mining. The conclusion is drawn that the Selenga River water flowing from the territory of Mongolia cannot directly affect the quality of water in Lake Baikal. 相似文献
10.
Concentrations of Zn in the surface (river and lake) and subsurface waters are assessed in the basin of the Selenga River—the
main tributary into Lake Baikal. Specific geographical features are revealed in Zn distributions in natural waters, which
are determined by different Zn concentrations in drained rocks and soils and by the geochemical redox conditions of Zn migration.
Areas with low, medium, and relatively high Zn concentrations (as compared with their Clarke concentrations) are determined. 相似文献
11.
Jan Pietroń Jeffrey A. Nittrouer Sergey R. Chalov Tian Y. Dong Nikolay Kasimov Galina Shinkareva Jerker Jarsjö 《水文研究》2018,32(2):278-292
The Selenga River delta (Russia) is a large (>600 km2) fluvially dominated fresh water system that transfers water and sediment from an undammed drainage basin into Lake Baikal, a United Nations Educational, Scientific, and Cultural Organization World Heritage Site. Through sedimentation processes, the delta and its wetlands provide important environmental services, such as storage of sediment‐bound pollutants (e.g., metals), thereby reducing their input to Lake Baikal. However, in the Selenga River delta and many other deltas of the world, there is a lack of knowledge regarding impacts of potential shifts in the flow regime (e.g., due to climate change and other anthropogenic impacts) on sedimentation processes, including sediment exchanges between deltaic channels and adjacent wetlands. This study uses field measurements of water velocities and sediment characteristics in the Selenga River delta, investigating conditions of moderate discharge, which have become more frequent over the past decades (at the expense of peak flows, Q > 1,350 m3 s?1). The aims are to determine if the river system under moderate flow conditions is capable of supporting sediment export from the main distributary channels of the delta to the adjacent wetlands. The results show that most of the deposited sediment outside of the deltaic channels is characterized by a large proportion of silt and clay material (i.e., <63 μm). For example, floodplain lakes function as sinks of very fine sediment (e.g., 97% of sediment by weight < 63 μm). Additionally, bed material sediment is found to be transported outside of the channel margins during conditions of moderate and high water discharge conditions (Q ≥ 1,000 m3 s?1). Submerged banks and marshlands located in the backwater zone of the delta accumulate sediment during such discharges, supporting wetland development. Thus, these regions likely sequester various metals bound to Selenga River sediment. 相似文献
12.
The runoff of the Selenga R., the largest tributary of Lake Baikal, in recent two decades corresponds to a low-water period. Such decrease can be due to the global climate processes, which have an effect on the amounts of precipitation onto and evaporation from Selenga drainage basin, which is located in arid climate zone. The adaptation of Ecomag software complex to simulating river runoff in the Selenga Basin based on global databases (relief, soils, vegetation, and weather information) is described. The model was calibrated and verified, and the statistical estimates of calculation efficiency were constructed. The obtained model of runoff formation in the Selenga Basin was used to assess the possible changes in the climate and water regime in the XXI century with the use of data of global climate models under different scenarios of greenhouse gas emissions. Throughout the XXI century, the Selenga R. runoff may decrease by 10–40%, depending on the forecasted climate conditions. 相似文献
13.
Specific features of the geomorphology and hydrology of Selenga River delta are considered. Fractal theory is used to evaluate the fractal dimension of the river delta as a branched structure. The fractal dimension of the planar pattern of the Selenga and Volga deltas are evaluated for the first time using three independent methods. The obtained values are 1.38 and 1.72, respectively. 相似文献
14.
Seasonal variations in water temperature in Selenga Shallow Waters is studied. The contributions of the regimes of waves, river runoff, thermal fronts, and thermobars to the formation of physical structures are assessed. 相似文献
15.
Khazheeva Z. I. Urbazaeva S. D. Bodoev N. V. Radnaeva L. D. Kalinin Yu. O. 《Water Resources》2004,31(1):64-67
The overall concentration of Cu, Pb, Zn, Cr, Mn, and Fe are determined in the water and bottom sediments of the Selenga River delta. The concentration of Cu, Pb, and Zn is found to decrease in the lower course of the river, at the delta outlet. The concentration of Mn and Fe is found to decrease in the downstream direction from the river's upper course along the investigated delta arms, whereas the concentration of Zn and Cr in certain arms exceeds their concentration in the upper section of the delta. 相似文献
16.
V. V. Parfenova O. N. Pavlova I. A. Terkina M. Yu. Suslova T. Ya. Kostornova I. G. Nikulina V. N. Sinyukovich L. M. Sorokovikova 《Water Resources》2005,32(2):204-208
The distribution and abundance of some groups of saprophytic microorganisms in bottom sediments of Selenga Delta area were investigated. The species composition of 57 strains of the genus Pseudomonas was determined. The distribution of Actinomycetes in sediments was found to be uneven, they were represented by the genera Streptomyces and Micromonospora. Formation of the microbial community in bottom sediments of the investigated area is influenced by the Selenga River.Translated from Vodnye Resursy, Vol. 32, No. 2, 2005, pp. 227–231.Original Russian Text Copyright © 2005 by Parfenova, Pavlova, Terkina, Suslova, Kostornova, Nikulina, Sinyukovich, Sorokovikova. 相似文献
17.
Water Resources - The Selenga River, which originates in Mongolia, contributes about 50% of the total inflow into Lake Baikal. Hydroclimatic development and abrupt landscape evolution due to... 相似文献
18.
According to the two-term principle of zoning of mouth areas, parts of the mouth area of the Selenga River are recognized and their boundaries are determined based on hydrological–morphological characteristics. 相似文献
19.
The study is aimed to evaluate a hydrological simulation model intended for assessing climate change impact. A new test was suggested and applied to evaluate the performance of a physically based model of Selenga River runoff generation. In this test, to calibrate the model, an enhanced Nash–and-Sutcliffe efficiency (NSE) criterion was used, including trend-oriented reference (benchmark) models instead of the simple reference model used in the original NSE criterion. Next, modifications were made in the Differential Split Sample test (DSS-test) of V. Klemeš (1986), focused on differences in the model performance criteria for climatically contrasting periods, and a new statistical measure was proposed to estimate the significance of these differences. After that, model performance was evaluated for four sites within the catchment, three indicators of interest (daily, monthly, and annual discharge series), and the model ability to reproduce the observed trends in annual and seasonal discharge values was assessed. The model proved robust enough to be applied to assessing climate change impact on the annual and monthly runoff in different parts of the Selenga River basin.
相似文献20.
太湖草/藻型湖区沉积物-水界面环境特征差异 总被引：3，自引：0，他引：3
在太湖草、藻型湖区进行冬、夏两季多点采样,分别对采样点的水环境特征、泥面以上5 cm上覆水中营养盐以及沉积物的含水量、中值粒径、有机碳、氮、磷、金属元素和溶解氧进行测定.结果表明:夏季藻型湖区表层水体pH高于中、底层,冬季草型湖区各层水体pH高于藻型;草型湖区水体浊度夏季低于藻型,冬季反之;藻型湖区上覆水中的硝态氮和磷酸根浓度显著高于草型;草型湖区沉积物中含水量冬季显著高于夏季;草型湖区沉积物中总有机碳显著高于藻型;Fe、Zn、Ca、Pb、Na和K等元素在草、藻型湖区间差异显著;沉积物中溶解氧表现为冬季深于夏季,藻型深于草型的规律. 相似文献