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1.
Field observations showed that the characteristics of chemical composition of waters and the development of plankton algae in the lakes within the delta of the Selenga river are determined by their flowage. The most open Lake Nekipelovskoe communicates with the Selenga outlets throughout a year, and Lake Zavernyaikha only at the period of an open channel. Lake Semenovskoe and Lake Khlystov Zaton are located in the islands and are isolated from the outlets. According to composition of main ions, the lakes under investigation refer to the hydrocarbonate class, the calcium group. The sum of ions in the water of Lake Nekipelovskoe approaches the one in the Selenga (86?221 mg/dm3), and the highest sums of ions were recorded in the wintertime in the lakes isolated from the outlets (446?743 mg/dm3). The lakes of the delta are characterized by a high trophicity. The maximum concentrations of total phosphorus in Lake Nekipelovskoe and Lake Zavernyaikha were 68 and 122 μg mg/dm3, and in Lake Semenovskoe and Lake Khlystov Zaton ?0.8 and ?0.63 μg mg/dm3, respectively. The most intense development of algae is observed in Lake Zavernyaikha, which is due to the high population of Baikal endemics. Lake Zavernyaikha showed a close negative correlation between the concentration of NO 3 ? , mineral phosphorus and phytoplankton biomass; the correlation coefficient was ?0.8 and ?0.63, respectively. The lakes exhibited increased contents readily hydrolysable organic matter, and a decrease in dissolved oxygen concentration in winter; hydrogen sulfide was repeatedly recorded in Lake Khlystov Zaton. The water quality in the lakes during the springtime varies from “quite clean” to “weakly polluted”; at low-water periods, especially in winters, it can drop to the category of “exceedingly dirty”. The water quality of the Selenga can be influenced by the lakes during spring floods when material accumulated during the wintertime is transported to the river outlets and further to Lake Baikal.  相似文献   
2.
Changes in chemical runoff of the main tributary of Lake Baikal, the Selenga River, observed since the mid-1990s, and determinant factors of these changes are under consideration. The estimates derived are indicative of a 20–40% reduction in the annual removal of dissolved substances because of a decrease in the water runoff of the river due to climate oscillations. The decreased inflow to Lake Baikal of mineral substances, especially silicon, nitrogen, and phosphorus, can lead to disturbance of production processes in Lake Baikal.  相似文献   
3.
Concentrations of major ions in surface waters of the rivers of Khara-Murin and Snezhnaya are compared based on data of many-year observations carried out in the 1950s and 2000s. The concentrations of HCO 3 ? , Cl?, Ca2+, Mg2+, Na+ + K+ are shown to be stable. A considerable increase in SO 4 ?2 concentration was revealed.  相似文献   
4.
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   
5.
The dynamics of the entry of sulfates and nitrate nitrogen into Lake Baikal together with its influent waters is outlined. Changes in the discharge of chemical components by large water streams are largely determined by the entry of ingredients as part of effluents. It is shown that the current increase in the flow of pollutants from the atmosphere has a dramatic effect on chemical composition of water in small rivers of Southern Baikal with low mineralization.  相似文献   
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Based on the comprehensive hydrochemical and hydrobiological studies of the Selenga River near the Naushki settlement carried out in 2010, the quality of water flowing from the territory of Mongolia is assessed. The comparison with the results of the previous years indicates that the water quality deteriorated due to the intensification of economic activity in the river basin and unfavorable climatic factors.  相似文献   
9.
Water Resources - A sanitary–bacteriological and hydrochemical survey of rivers flowing into Lake Baikal near Listvyanka Settl. was carried out in period from 2014 to 2015. Water quality at...  相似文献   
10.
The seasonal and year-to-year dynamics of the concentrations of biogenic elements and organic matter, as well as quantitative composition of phytoplankton in water of Selenga delta branches is studied. The distribution of those components from the mouth of the Kharauz branch (the main branch) to the water area of the Selenga shallows in different hydrological seasons is shown. The concentrations of nitrate nitrogen and phosphate phosphorus in the zone of mixing of river and lake waters have been found to drop by 30 and 50%, respectively, because of the consumption of those substances by phytoplankton.  相似文献   
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