Cheboksary Reservoir Research Articles

Composition, structure, and dynamics of phytoplankton in some left-bank tributaries of the Cheboksary Reservoir

The data on the composition, structure and dynamics of phytoplankton in morphologically different tributaries of the Cheboksary reservoir (the Vetluga, Kerzhenets and Vishnya rivers) are given. The floristic composition of algae includes 856 species and intraspecific taxa, algoflora is characterized as diatom-green-euglena algae. There is an increase in quantitative indicators of algocenosises from oligotrophic to oligotrophic-mesotrophic level in the middle course of the rivers, with mesotrophic-eutrophic level in the estuaries. The period of abnormally hot summer in 2010 led to increasing of vegetation of blue-green and dinophyte algae in the middle course and estuaries of the rivers. Since the early 2000s, penetration and naturalization of invasive algae species has been noted.

ЮРИНСКИЕ ДРЕВНОСТИ. ПРОДОЛЖЕНИЕ ИССЛЕДОВАНИЙ, НАЧАТЫХ А.Х. ХАЛИКОВЫМ

The article discusses and analyzes the results of field work of the Mari archaeological expedition and the author on a seasonal hunting site of the Stone and Early Bronze Age. Polyanskaya V site, located in the Western part of the Republic of Mari El, was attributed by its discoverer (A.H. Khalikov) to the circle of monuments of the Balakhna Neolithic culture, represented by hundreds of settlement monuments in the Middle Volga region. The main ceramic complex of the site consists of fragments of walls and corollas of vessels with pit-comb ornamentation. In the late 1970s, the Polyanskaya V site was partially destroyed during the creation of engineering protection of the Yurinskaya lowland from flooding by the waters of the Cheboksary reservoir. Due to the lack of possibility to conduct stationary excavations of the monument, V.V. Nikitin (Mari archaeological expedition) and we regularly collected lifting material. These fees were most effective in 2000-2005. The collection of flint inventory of the Polyanskaya V site has been significantly expanded. Thanks to our findings of throwing tools in the damaged by wind erosion cultural layer of the site, it was possible to more accurately determine the cultural identity of porous ceramics, which are also found on the monument square. Visiting the site by groups of hunters of the Eneolithic era is illustrated by flint arrow that have analogies in the inventory of Volosovo type settlements of the Mari Volga region. Keywords: Balakhna culture, stone tools, ceramics, archaeological collection

EVOLVEMENT AND DEVELOPMENT OF CHEBOKSARY HPP: TO THE HISTORIOGRAPHY OF THE ISSUE

The article presents an overview of research and social-political literature on evolvement and development of Cheboksary hydroelectric power plant. The authors carried out the analysis of scientific papers and publications using such scientific methods as system analysis, logical and structural research. The content of the article considers two periods in the historiography of the topic, each of which has its own peculiarities. The first period is mainly characterized by social-political literature. Publications are devoted to the grandeur of Cheboksary HPP construction. Particular attention is paid to the works, which were published by immediate participants of construction of the hydro-engineering complex. Historiography of this period mainly notes positive aspects of construction, negative aspects are either disregarded or considered insignificantly. The second period is characterized mainly by publications in periodicals. They are observed to contain more critical statements about the state of the hydroelectric power plant and Cheboksary reservoir. Articles about the difficulties in development of the hydro-engineering complex are analyzed. At this time studies of representatives of natural and technical sciences start to be published. They are devoted mainly to problems related to the rise of the water level in Cheboksary reservoir to the design mark. The analysis of publications on the ecological state of the flooding zone and hydrogeological survey of the hydro-engineering complex is also presented.
 
 The study makes it possible to state that the historical aspect of Cheboksary HPP evolvement and development in historiography has been studied extremely insufficiently. Most sources are marked by a departmental focus, journalistic character and a weak documentary base. The results of the review showed that there are no complex studies on the history of implementing the hydroelectric power plant construction in domestic historiography. The materials of the article can be used for further research of this topic, as well as when writing regional natural history works.

Anthropogenic Load and the Effect of Drainage Area on the Diffuse Runoff of Nutrients into a Large Water Body: Case Study of the Cheboksary Reservoir

A brief description is given for the natural conditions and economic activity on a local drainage basin of the Cheboksary Reservoir (less the Oka Basin). The main principles of a new version of landscape-hydrological method used to evaluate nutrient runoff from the drainage basin into water bodies are given. The article presents the values of the runoff of these elements into the Cheboksary Reservoir calculated taking into account the effect of the drainage basin and anthropogenic load from mineral and organic fertilizers applied on agricultural fields and the input of wastes onto the drainage basin from the population that have no access to sewage system.

Planktonic Community of a Large Eutrophic Reservoir during a Period of Anomalously High Water Temperature

The rise in temperature to anomalously high values for the Middle Volga (27–29°С) in the Cheboksary Reservoir in the summer of 2010 significantly increased (2–14 times) the biomass of some plankton components (phytoplankton, bacterioplankton, protozoans, and zooplankton) and the community as a whole. The total plankton biomass reached a record value of 3 g C/m3 for deep parts in the Upper and Middle Volga. The cyanobacterial bloom of water was observed in most of the reservoir. Differences in the structure of the plankton community and the bacterioplankton-to-phytoplankton production ratio were found between riverine and lacustrine parts of the reservoir. Autotrophic (in the riverine part) and heterotrophic (in the lower lacustrine part) stages of the plankton community development were observed simultaneously in different parts of the reservoir. The functioning of the plankton community in a water temperature that exceeded usual summer heating by almost 9°C led to the deterioration of water quality in the reservoir.

Dynamics and Overgrowth of Volga Reservoirs

Data on the overgrowth level and biomass reserves in Volga reservoirs, collected in 2003–2009, are given. The long-term dynamics and the character of overgrowth of the Ivankovo, Uglich, Rybinsk, Gorki, Cheboksary, Kuibushev, Saratov, and Volgograd reservoirs are analyzed taking into account the published materials of the previous studies. The analyzed data include the specific features of variations in the diversity and production of vegetation cover in reservoirs in various natural–climatic zones in the Upper, Middle, and Lower Volga, as well as reservoirs with filling level either constant or abruptly varying (the Rybinsk and Kuibyshev) over years and within a year.

Опыт использования функциональной классификации фитопланктона для оценки качества воды некоторых левобережных притоков р. Волги (бассейн Чебоксарского водохранилища)

Опыт использования функциональной классификации фитопланктона для оценки качества воды некоторых левобережных притоков р. Волги (бассейн Чебоксарского водохранилища)

Chlorophyll Content and the Modern Trophic State of the Volga River Reservoirs (2017–2018)

New data on the chlorophyll a (Chl a) content in the water of the Volga River reservoirs are presented. In years with different temperature regimes (2017 and 2018), the content of Chl a varied from minimal 2.2–13.8 to maximal 7.6–50.5 and 25.8–104 µg/L, respectively. As before, the Chl a concentration in the Volga cascade decreases from the upstream reservoirs to downstream ones; the maximum is recorded in highly eutrophic Shosha reach of the Ivankovo Reservoir and in the estuarine section of the Oka River in the Cheboksary Reservoir; and the local increase in Chl a is also recorded in tributaries and their mouth areas, protected shallow areas, and near-dam zones. The mean Chl a concentrations characterize the Ivankovo, Uglich, and Cheboksary reservoirs as eutrophic and the Saratov and Volgograd reservoirs as mesotrophic; the trophic status of the Rybinsk, Gorky, and Kuibyshev reservoirs varies from mesotrophic to moderately eutrophic and eutrophic.

Water Quality Assessment of Some Right-bank Tributaries of the Volga River (the Cheboksary Reservoir Catchment) using Phyutoplankton Functional Classification

Water quality assessment of the right-bank tributaries of the Cheboksary Reservoir (Kudma and Sundovik) using the phytoplankton functional group method and calculated on its basis community index Q, showed predominance in the Kudma River indicators of eutrophication and water pollution by the organic substances (codons D and W1). The main functional groups in the potamoplankton of the shorter river (Sundovik) were codons D and TB, which comprised the planktonic diatoms randomly entering the water column from benthic communities. The use of different approaches in the water quality assessment has demonstrated higher sensitivity of the community index Q and ecological quality ratio EQR as compared with the saprobiological analysis.

Dissolved and particulate nutrient transport in the Cheboksary Reservoir

The reservoirs of the Middle and Lower Volga are prone to eutrophication due to an exceptionally large anthropogenic impact from agricultural, industrial and urbanized areas. To better understand the exact factors driving this process, it is necessary to have accurate data on the nutrient loading of the reservoirs, which comes mostly as river inflow, but there is very little information on the structure of the rivers nutrient budget. Our summer field studies on a sector of the Cheboksary Reservoir from Nizhniy Novgorod to its lacustrine part in 20172019 provided a detailed picture of the dynamics of suspended and dissolved nitrogen and phosphorus and mineral silicon as the Volga River experiences significant hydrological and geochemical changes. The Oka River is shown be the primary supplier of nutrient elements into the reservoir which creates some distinct features of the nutrient regime of an over 100 km long part of the Volga cascade and contributes to a noticeable increase of the main rivers nutrient load.

Zooplankton Communities of the Middle River Part of the Cheboksary Reservoir and Factors Influencing Their Species Structure

Modern methodological approaches were applied to analyze the zooplankton community spatial distribution (with the example of the middle river part of the Cheboksary Reservoir). Zooplankton communities were sampled in the middle river part of the Cheboksary Reservoir (from the city of Nizhny Novgorod to Vasilsursk town) in the summer low-water period in 2018. The boundaries between the communities in the Cheboksary Reservoir were gradually changing during the history of the Cheboksary Reservoir from the time of its construction to present. In the middle river part of the Cheboksary Reservoir there are two distinct spatially stable zooplankton communities associated to the Oka and Volga streams. The distinction between these two zooplankton communities was demonstrated by hierarchical cluster analysis. Redundancy analysis has shown that chlorophyll- a and pH were the main factors influencing the specific zooplankton structure. Chlorophyll- a concentration reflects the meso-scale heterogeneity of the horizontal phytoplankton distribution and hence the distribution of the zooplankton’s food sources. The relation of zooplankton to pH level reflects the high sensitivity of the species of the genus Brachionus Pallas, 1766 to high acidity. The influence of pH as an environmental factor was less evident. However, this variable is well known as one of the leading factors determining the structure of zooplankton communities. Its role in zooplankton community assembly of lowland reservoirs deserves further investigation.

Composition and development of cyanobacteria of the Cheboksary reservoir and its tributaries (Nizhny Novgorod region)

Composition and development of cyanobacteria of the Cheboksary reservoir and its tributaries (Nizhny Novgorod region)

Особенности современного формирования стока биогенных веществ в центральной части Русской равнины

An attempt to evaluate the diffuse removal of mineral nitrogen and phosphorus from river catchments in the central part of the Russian Plain has been made. A rough esti-mate of the annual water-biogenic balance for the Linda and Kudma river catchments, which are the tributaries of the Cheboksary reservoir, and river catchments of the Kursk region is presented. It is shown that the diffuse removal of biogens from river catchments exceeds their removal into water bodies with wastewater, and in recent years (2008–2018) it reached 75–95 %. Along with the surface component of the runoff, the contribution of underground runoff and precipitation to this process is estimated. It is found that on the catchment area of the lateral tributary of the Cheboksary reservoir, the natural component in the diffuse removal of nutrients predominates comprising 55–75 % and more their total removal. Due to the intensive anthropogenic load in the Kursk region, the natural supply of biogens to the river catchments (30% nitrogen and 5% phosphorus) is much less than their anthropogenic input. The livestock business, poultry farming, urban areas (including the road network) and fertilization are the most significant sources of anthropogenic nutrient input. Resent chang-ers in nitrogen and phosphorus removal from river catchments are assessed. They have oc-curred mainly due to climatic changes in the water balance – due to decrease in the surface slope runoff and due to increase in the runoff of infiltration origin (underground runoff and vekhovodka). Annual biogens export from the Linda and Kudma river catchments has in-creased significantly (by 20–30 %). At the same time in the Kursk region, due to a reduction in the annual river flow (by 30–40 %), nutrient removal has decreased.

Aspects of the modern biogens runoff formation in the central part of the Russian Plain

The removal of biogenic substances (mineral nitrogen and phosphorus) from river catchments and its modern aspects of formation are considered. A rough estimate of the annual water-biogenic balance for the Linda and Kudma river catchments, which are the tributaries of the Cheboksary reservoir, and the river catchments of the Kursk region is presented. It is shown that the diffuse removal of biogens from river catchments exceeds their removal into water bodies with wastewater. Not only anthropogenic, but also natural factors play an important role in the biogens export to the rivers and waterbodies. Resent changes in biogens removal from catchments are assessed.

Особенности современного формирования стока биогенных веществ в центральной части Русской равнины.

An attempt to evaluate the diffuse removal of mineral nitrogen and phosphorus from river catchments in the central part of the Russian Plain has been made. A rough esti-mate of the annual water-biogenic balance for the Linda and Kudma river catchments, which are the tributaries of the Cheboksary reservoir, and river catchments of the Kursk region is presented. It is shown that the diffuse removal of biogens from river catchments exceeds their removal into water bodies with wastewater, and in recent years (2008–2018) it reached 75–95 %. Along with the surface component of the runoff, the contribution of underground runoff and precipitation to this process is estimated. It is found that on the catchment area of the lateral tributary of the Cheboksary reservoir, the natural component in the diffuse removal of nutrients predominates comprising 55–75 % and more their total removal. Due to the intensive anthropogenic load in the Kursk region, the natural supply of biogens to the river catchments (30% nitrogen and 5% phosphorus) is much less than their anthropogenic input. The livestock business, poultry farming, urban areas (including the road network) and fertilization are the most significant sources of anthropogenic nutrient input. Resent chang-ers in nitrogen and phosphorus removal from river catchments are assessed. They have oc-curred mainly due to climatic changes in the water balance – due to decrease in the surface slope runoff and due to increase in the runoff of infiltration origin (underground runoff and vekhovodka). Annual biogens export from the Linda and Kudma river catchments has in-creased significantly (by 20–30 %). At the same time in the Kursk region, due to a reduction in the annual river flow (by 30–40 %), nutrient removal has decreased.

A Record of the Tropical Species Thermocyclops Taihokuensis Harada, 1931 (Copepoda: Cyclopoida) in the European Russia

In July 2018, in the estuary area of the Sura River (a tributary of the first order of the Cheboksary reservoir, Nizhny Novgorod oblast, Russia) was record a tropical alien co-pepod Thermocyclops taihokuensis Harada, 1931 (Copepoda: Cyclopoida). Information about the discovery of this species in the European part of Russia is extremely scarce. There is only one report of the discovery of this species in the lower reaches of the Volga River. The main habitat of T. taihokuensis is distributed in East and Central Asia, as well as tropical regions. The paper presents a brief description of T. taihokuensis with updated drawings. The records in the estuarine area of the Sura River T. taihokuensis females had an average size of 1060±20 pm. The spread of tropical crustaceans beyond their natural habitat appears to be linked to human activities and the transport of ballast water by ships. In addition, the concept of zoochoria suggests that the settlement of this species may be associated with the transfer of resting stages of T. taihokuensis by migratory species of waterfowl. Thus, migration routes of various bird species from the Arctic and temperate climatic zones to subtropical and tropical regions pass over European Russia. Alien species have high phenotypic and ecological plasticity and are able to introduce ecosystems into imbalance. That is why new studies of the Sura River and the Cheboksary reservoir will help not only to judge the success of the naturalization of T. taihokuensis, but also about the environmental consequences of the penetration of this species into the territory of the European part of Russia.

Modern changes of nutrients’ removal into the southern forest zone rivers of Volga basin

The article analyzes on the example of the Linda river basin, the tributary of the Cheboksary reservoir, contribution of the main elements of its vertical hydrological structure (precipitation, surface and underground runoff, verhovodka runoff) in the formation of nutrients removal from rivers catchments in the southern forest zone of the Russian plain. The removal of nutrients from the Linda river catchment area with various elements of water flow for the year, its high-water and low-water periods was calculated. It is shown that due to the increased role of the changed hydro-climatic conditions, especially due to the increased flow of infiltration origin (underground and verhovodka runoff), the nutrients removal has increased in recent years. Anthropogenic component of nutrient leaching into the Cheboksary reservoir from Linda river catchment was identified. It is reduced in recent decades by the background dispersion in the catchment, diffuse nutrients leaching to surface and underground flow of natural origin.

Sustainable use of natural resources in a hazardous landslide slopes of Cheboksary reservoir (river Volga)

Often uncontrolled construction with insufficient consideration of the geotechnical and hydrogeological conditions of the territory, the increased man-made impact on the slope in the conditions of growing urbanization are leads to serious problems: landslide deformations and emergencies on the coast of the Cheboksary Reservoir, on the territory of the Cheboksary urban district and in the adjacent territories of Chuvash Republic. The increase in recreational load on coastal geomorphic systems also contributed to the activation of landslide, erosion, deflation and other dangerous relief-forming processes, and also affected the quality of water resources. The problem of assessing the stability of hazardous landslide slopes and slopes for civil, transport construction and recreational development of the coast of the Cheboksary reservoir is analyzed in this article. Minimizing the risk and damage from hazardous slope processes, including landslide, depends on the knowledge of the structure of the landslide geomorphic system and the slope array, harmonization of the interaction of the components of the designed object with the components of the geological environment (GE). On the basis of a professional analysis of engineering and geological factors, correct design models are proposed, with exact values of the slope stability coefficient (Cs) and rational design solutions leading to a reduction in natural and man-made risks.

Biogenic Runoff from the Nizhny Novgorod Area

The methodical approaches to the integral estimation of the biogenic diffuse export from urbanized areas have been developed and tested, using the Nizhny Novgorod area as an example in the absence of direct hydrological observations. The conditionally natural runoff of the Rakhma River, the catchment of which is mostly occupied by the present-day Nizhny Novgorod area, has been reproduced based on the RosHydroMet data on the Sundovik River-analog runoff for 2010–2017. The interannual distribution of the Rakhma River runoff has been analyzed, and the variations in the groundwater and surface runoff components have been estimated with regard to the joint impact of climatic and anthropogenic factors. The surface component of the Rakhma River runoff has been shown to increase twice while the groundwater component, to decrease by 38%. In this case the groundwater runoff value remains rather large (63 mm per year), accounting for 33% of the total river runoff. The calculations of the biogen export by the river into the Cheboksary Reservoir in different seasons, less the biogen input with wastewater, have been illustrated. The present-day diffuse export of biogens from the Nizhny Novgorod area has been roughly estimated. The export of mineral nitrogen (195 kg km–2) is maximal in the cold season and that of phosphorus (11 kg km–2), during the spring flood, respectively.

Changes in runoff and water quality in the catchment areas of the reservoirs

According to experimental data, a significant decrease in the surface slope runoff from agricultural land in recent decades in the southern part of the Russian plain, including the Volga basin, as a result of mainly climate change has been shown. Part of the decrease in surface runoff entering rivers and water bodies from agricultural land is offset by increased runoff from urban areas. In general, the diffuse removal of biogens (nitrogen and phosphorus) has decreased, although in many areas it exceeds their flow into rivers and wastewater reservoirs, in particular in the catchment area of small tributaries of the Cheboksary reservoir.