scholarly journals The Change of the Water Regime of the Volga River in the Area of the Protected Island Bakhilovsky

Author(s):  

The ecological state of the protected Islands Seredysh and Shalyga (now Bakhilovsky island) depends on the water content and flow of the Volga River. We have analyzed the long-term changes in the water flow of the Volga River for the period 1958-2017 in the alignment Zhiguli dam, located 12 km upstream from the island. According to the average annual water consumption, there are three periods that differ from each other in water content: low-water period (1958–1976), high-water period (1977–1997) and the period of average water content (1998–2017), with extremely low-water (1967, 1973, 1975, 1976, 1977, 1996) and extremely high-water (1966, 1979, 1981, 1990, 1991, 1994) years. In highwater years, during the passage of the spring flood, the island is almost completely flooded, and in low-water years, during the summer low water, the area of the island increases and changes its configuration.

2019 ◽  
Vol 38 (3) ◽  
pp. 225-239
Author(s):  
Alexey P. Kuklin ◽  
Balzhit B. Bazarova

AbstractThe study of aquatic vegetation in the littoral of the dimictic water bodies of taiga is of particular interest in case of long-term observations carried out under conditions of climate fluctuations. During the low-water period, drying of the littoral with a decrease in the water level leads to the changes in phytomass of macrophytes, as well as in the composition of species and their distribution by depth. The area of littoral covered with ice in winter is also large in the low-water period; it affects the growth of perennial plants. When the water level decreases, the sand beach replaces the sand and pebble beach; it leads to the disappearance of epilithon and the predominance of rooting plants. The features of vegetation were determined for each period of water content. The low-water period is characterised mostly by grass-type vegetation; the high-water period is characterised by vegetation of mixed type.


Vestnik MGTU ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 202-213
Author(s):  
Vladimir Anatolyevich Seleznev

In the Volga River water, sulfate ions rank second among the main anions in terms of their contribution to water mineralization. To study the seasonal variability of sulfate concentration, an analysis of long-term data of hydrological and hydrochemical observations obtained on the River Volga (in the outlet section of the Kuibyshev reservoir) has been carried out. For the period of 2001-2018 the average annual water consumption in the dam section varied in the range of 6.2-9.0 thousand m3/s, the average annual concentration of sulfates was 55 mg/dm3, the highest - 64 mg/dm3, and the lowest - 45 mg/dm3. The content of sulfates in the reservoir is formed mainly under the influence of the Volga River water coming from the Cheboksary reservoir and the Kama River water coming from the Nizhnekamsk reservoir. The sulfate content is characterized by significant seasonal variability. During the winter low-water period, the highest concentrations of sulfates were observed with a maximum in April, before the beginning of the spring flood (67 mg/dm3). During the flood, the content of sulfates decreased, reaching the lowest values during the summer low-water period in August (44 mg/dm3), and then, from September, the concentration of sulfates gradually increased, reaching 57 mg/dm3 at the beginning of the winter low-water period. Over a long-term observation period, the amplitude of sulfate fluctuations was 34-87 mg/dm3, and its value depended on the water content of a particular year. In dry years, the concentration of sulfates in the water increased, and in dry years, it decreased. In the seasonal context, the main differences in sulfate concentrations in dry and high-water years occurred during the spring flood and winter low-water period, and during the summer - autumn low-water period, the differences became minimal.


2001 ◽  
Vol 38 (4) ◽  
pp. 720-731 ◽  
Author(s):  
Luc Morissette ◽  
Michel W St-Louis ◽  
Gordon C McRostie

Using settlement observations published for several embankments on marine clays of the Champlain Sea, an empirical model is proposed to estimate long-term settlements. The effect of the overconsolidation ratio is taken into consideration within the model. Footing- and raft-type foundation cases are considered to give guidelines when using the model for these foundation types. A specific embankment resting on a foundation of high water content clay with a high compressibility index demonstrates that a correction factor should be applied under these conditions.Key words: settlement, embankment, Champlain Sea clay, consolidation, empirical model.


Author(s):  
G.Kh. Ismaiylov ◽  
◽  
N.V. Muraschenkova ◽  
I.G. Ismaiylova

Water resources are one of the most important problems of our time. Population growth, industrial and agricultural development all over the world entail an ever-increasing demand for clean fresh water. These circumstances induce hydrologists to actively and thoroughly study the problem of studying water resources, changing their quantitative and qualitative characteristics in time and space, and the peculiarities of changes in the water regime of river runoff under conditions of climatic changes. In this work, we performed a retrospective analysis and assessment of changes in the water content of the Upper Don basin over a long 126-year period of hydrometric observational data (1881/1882–2006/2007). To study the change in the water content of the Upper Don River, we used the difference integral curves of the annual and seasonal (spring flood, summerautumn and winter low-water periods) runoff. Regularities of long-term cyclical fluctuations in the water content of the annual and seasonal runoff of the Upper Don are obtained. A retrospective analysis of long-term data of hydrometric observations made it possible to distinguish long phases of high-water, medium-water-content and low-water years on the differential integral curves of river runoff. Each phase, which is long in terms of water content, contains groups of years of shorter duration, for example, 2–3-year and 4–5-year phases of increased and decreased water content in a river. The analysis of the differential integral curves of the annual and seasonal runoff made it possible to establish that the long-term fluctuations in the annual runoff of the Upper Don are rhythmic, in contrast to the runoff of the spring flood, summer-autumn and winter low-water periods, which are characterized by a monotonic regime.


Author(s):  

The article is devoted to present-day specific features of the Don River basin rivers spring tide. On the basis of the recent data on the rivers’ water regime changes of maximal water flow, duration of high water period, high water runoff fractions in the annual runoff and hydrograph forms have been shown. It has been demonstrated that the spring tide character change is closely linked with the other phases of rivers’ water regime change.


Author(s):  
Natalia Ivanovna Chavychalova ◽  
Dina Germanovna Taradina ◽  
O.M. Vasilchenko ◽  
Raigul Sadyakhovna Mukhanova

A retrospective review of the main factors that caused the decline in the reproduction of semi-passable fish in the lower reaches of the Volga River is given. Long-term data on the yield of juvenile semi-passable and river fish are presented, on the basis of which the current state of natural reproduction of roach, carp is estimated as low; bream, bluefin and perch — satisfactory; crucian carp, gaster and rudd — safe. Overregulation of the Volga River flow near Volgograd violated the natural conjugacy of water and temperature regimes. In the regulated period, the timing of the onset of spawning temperature in most cases is ahead of the flooding of the strips. The lag of the delta spawning grounds begins when the runoff is less than 120 km³ and reaches the maximum values (up to 27 days) in years with extremely low water content. The delay in flooding of spawning grounds in conditions of unsatisfactory water content leads to the accumulation of producers in limited areas of strips and simultaneous spawning of fish with different ecology. This leads to increased food competition of the larvae and reduced survival. After the flow was regulated, the rates of rise and fall of the hollow waters increased by 2 times, the hatching of the larvae, as a rule, coincided with the onset of the flow of the hollow waters. The mass removal of larvae into the delta watercourses at the early stages of ontogenesis, due to their lack of viability in river conditions, leads to a decrease in the productivity of spawning grounds. In the modern period (2003– 2019), due to the predominance of unfavorable hydrological regime, the duration of high water and flooding of the poloi years, and in order to clarify the yield of juvenile fish in the lower reaches of the Volga, its accounting was carried out not only in the poloi of the delta, but also in the coastal watercourses (where a large number of larvae and fry that rolled off the poloi and from local spawning), in the kultuch zone and on the poloi of the lower zone of the Volga-Akhtuba floodplain.


Author(s):  
Zh. R. Shakirzanova ◽  
V. М. Boyko ◽  
M. V. Goptsiy ◽  
Е. І. Todorova ◽  
А. A. Dokus ◽  
...  

Introduction. In Ukraine, under the conditions of current climate variability, the water content of the rivers, including the period of spring flood, changes. Against the background of the general tendency of reduction of the runoff characteristics of the spring flood of the rivers in Ukraine, formation of catastrophic floods on rivers leading to flooding of territories and destruction of economic objects should not be ruled out. The research is aimed at solving an important scientific-applied and socio-economic problem of improving the water management in the basin of the country's large waterway, the Dnipro River, through probabilistic assessments of hydrological threats which include spring flood and its consequences – floods of various magnitudes. Therefore it is necessary to create a unified universal mathematical model for formation, calculation and long-term forecasting of water flood characteristics, and to implement it for the Dnipro Basin's rivers (including small ones which usually are not recorded in the data of runoff observations), taking into account the climate changes of the winter-spring period. The purpose consists in prognostic assessment of the hydrological regime characteristics of the Dnipro Basin's rivers during the most full-flowing phase of their water regime, the spring flood, for the purpose of spatial monitoring of the state of water objects during this period. The research offers the method of territorial long-term forecasts of the spring floods characteristics which is based on the theory of channel isochrones and consideration of the complex of runoff formation hydrometeorological factors with preliminary determination of the type of water content of spring flood. The spatial representation of forecast variables in cartographic form will allow estimation of the size of the water flood and its long-term repeatability throughout the entire basin and preparation of forecasts for separate rivers, regardless of the degree of their hydrological exploration. Results. As a result of application of the complex forecasting method of territorial long-term forecasts of the spring flood characteristics of the rivers (through the example of the Dnipro Basin within Ukrainian borders), typification of floods based on their water content was performed using a discriminant function apparatus which takes into account the probable combination of hydrometeorological factors of spring floods. In terms of regional dependencies forecast of runoff depths and maximum water flow of floods was conducted and probability of their occurrence in the long-term period was determined. Assessment of the forecast methodology provided satisfactory results, and, under the conditions of long-term tendency to decrease runoff depths and maximum water flow during the spring flood of the Dnipro Basin's rivers, it is proposed to specify the average long-term values of these variables which are basic ones when applying the method of territorial long-term forecasts of the maximum spring runoff of rivers. A spatial preliminary estimation of the size of spring floods within the Dnipro River Basin was also fulfilled. The authors completed implementation of the method of territorial long-term forecasts of spring flood characteristics using the data of the water flood of 2017-2018. Conclusion. In general, taking into account the obtained criteria of accuracy, the method can be considered effective and recommended for release of annual long-term forecasts of the rivers' spring flood characteristics at in operational units delivering forecasting hydrological services to respective consumers. Through the example of the spring flood of 2017-2018 the possibility of forecasting assessment of the hydrological regime characteristics of the Dnipro Basin's rivers was shown which allows determining the zones of increased river runoff over the spring period and increased threat of possible flooding of surrounding areas, especially when the floods with a rare probability of excess occur.


KOVALEN ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 218-223
Author(s):  
Riri Fauziyya ◽  
Anjar Hermadi Saputro

Meatballs and wet noodles are foods that are favored by the community. The high water content causes these two types of food to be vulnerable and easily damaged in storage. The addition of chemicals such as preservatives in the manufacture of food products is carried out by producers so that the products are more durable, economical, and produce maximum profit. One chemical that is often misused for food preservatives is formaldehyde. Formalin is a dangerous chemical that is carcinogenic, mutagenic, corrosive, and irritating. This study aims to determine whether there is formalin content in meatballs and wet noodles that are sold in the districts of Sukarame, Wayhalim, and Sukabumi. This research was conducted in a qualitative analysis using Schiff's reagent on 30 samples of meatballs and 30 samples of wet noodles which were sold in Sukarame, Wayhalim, and Sukabumi. The results showed that 10 samples of meatballs and 2 wet noodles showed positive results containing formaldehyde.  This shows that around 33.3% of the meatball sample and 6.66% of the wet noodles sample analyzed were identified to contain formaldehyde so that they are not safe for consumption in the long term and people must be careful in selecting meatballs and wet noodles for consumption. Keywords: Qualitative analysis, formalin, meatballs, wet noodles


2021 ◽  
Vol 14 (6) ◽  
pp. 679-690
Author(s):  
N. M. Mineeva

Abstract On the basis of field observations in 2009–2019, the seasonal and long-term dynamics of chlorophyll at six standard stations of the Rybinsk Reservoir is considered. The fluorescence method is used to determine chlorophyll. The average chlorophyll content at stations varies from the minimum 3.5–10.8 to the maximum 16.9–40.5 μg/L in different years and from 12.0 at station 5 (Sredny Dvor) up to 21.6 μg/L at station 2 (Mologa) on average for the entire period. The seasonal dynamics of chlorophyll is characterized by spring; summer; and, in some years, autumn maxima. With the same type of seasonal dynamics, the change in chlorophyll at the stations is to varying degrees coupled in the years of observation and is most often correlated in neighboring areas. Significant differences in the amount of chlorophyll at the stations are observed during surveys carried out within one day and are determined by the complex hydrological structure of the reservoir; active dynamic processes; and, in the spring, by the thermal regime. The presence of stable large circulation zones smoothes out the spatial differences of chlorophyll, the average seasonal concentrations of which do not differ significantly at all six stations in years with an average water level, and at four stations of the Main Reach in extremely high-water years. A close correlation in long-term dynamics is revealed for the average chlorophyll concentrations for the growing season at six stations, as well as at each station and the reservoir as a whole. The results of the work confirm the reliability of the data obtained for assessing the ecological state of the Rybinsk Reservoir.


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