scholarly journals Assessment of Hadzhibeysky estuary and forecasting possible water level in it

2017 ◽  
pp. 156-163
Author(s):  
Zh.R. Shakirzanova

Introduction. Modern hydrology of the Hadzhibeysky estuary is due to natural and anthropogenic factors and characterized by their intense economic use. Since the beginning of the last century, there was an intense discharge of municipal waters from Odessa (biological treatment plant "North"). This led to a significant increase in the levels of water in the estuary, which threatened to destroy the dam that separates the estuary from the sea, with the possible flooding of residential areas and enterprises of the Peresip area, as well as the road, on the dam, especially in disastrously high water years. Purpose. The purpose problems – are estimation of filling the closed estuaries-reservoirs in north-west area of the Black sea and long–term forecasting of their condition during the spring period of year. The first task – an analysis of conditions of the Hadzhibeysky estuary in the presence of an exceptional spring flood and rain floods of exceedance probability (P = 1%). The second task – is to develop a methodology for the long-term forecasting of filling of the Hadzhibeysky estuary during the spring flood, which is the most abundant phase in the hydrological regime into the territory. Results. For the first time, the possibility of assessing the filling degree surface water from melting snow and rainfall when the estimated probability of exceeding P=1% in the closed estuaries-reservoirs of the Black Sea areas. The method of the long-term forecast of surface water during the spring period for the closed estuaries was substantiated. Typification of spring floods in accordance with their water content according to the model – discriminant function DF, which takes account of the complex of factors having an influence upon conditions of spring flood formation. Setting the probability of occurrence of the forecasting flow layers in the long-term period are implemented. Conclusion. This method allows risk assessment for sustainable land – and water use planning within the Black Sea estuaries. The method of the long-term forecast was realized by the author in operational work at the Hydrometeorological Center of the Black and Azov Seas.

Author(s):  

The main problems of an engineering hydrology connected with the analysis of non-stationary sequences of hydrological characteristics, statistical inauthenticity of estimates, uncertainty of long-term forecasts, taking into account the need of the accounting of anthropogenic factors of the runoff alterations are discussed. The novel complicated hydrological tasks reasons have been analyzed, problems of the extreme events hydrological analysis have been classified, issues of decision making in the various uncertain conditions have been explored. The problem of the input long-term forecast reliability in the process of water management computations has been studied with the Lake Baikal level fluctuations range as a study case. Relevant issues of the hydrological characteristics assessment in the conditions of future climatic changes uncertainty have been considered. The Bayesian method of probabilistic assessment of extreme water consumption and levels on water bodies in conjunction with possibilities of the long-term forecasting based on the atmosphere circulation models are recommended.


2019 ◽  
Vol 59 (6) ◽  
pp. 1008-1015
Author(s):  
A. D. Gubanova ◽  
O. A. Garbazey ◽  
D. A. Altukhov ◽  
V. S. Mukhanov ◽  
E. V. Popova

Long-term (20032014) routine observations of zooplankton in Sevastopol Bay (the Black Sea) have allowed the naturalization of the invasive copepod Oithona davisae to be studied in the Black Sea coastal waters. Inter-annual and seasonal variability of the species and their impact on the native copepod community have been analyzed. The invasion of O. davisae and their undoubted dominance in terms of abundance were shown to alter the community structure but, at the same time, the abundances of the native species did not decrease, excepting the Black Sea earlier invader Acartia tonsa. A significant decline in A. tonsa numbers over the stages of O. davisae establishment and naturalization provided evidence of competition between the species. O. davisae have been demonstrated to gain competitive advantage over A. tonsa, that ensured their fast dispersal in the Black Sea, acclimatization in the new habitat and the successful competition over native species.


Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 491-501 ◽  
Author(s):  
G. I. Shapiro ◽  
D. L. Aleynik ◽  
L. D. Mee

Abstract. There is growing understanding that recent deterioration of the Black Sea ecosystem was partly due to changes in the marine physical environment. This study uses high resolution 0.25° climatology to analyze sea surface temperature variability over the 20th century in two contrasting regions of the sea. Results show that the deep Black Sea was cooling during the first three quarters of the century and was warming in the last 15–20 years; on aggregate there was a statistically significant cooling trend. The SST variability over the Western shelf was more volatile and it does not show statistically significant trends. The cooling of the deep Black Sea is at variance with the general trend in the North Atlantic and may be related to the decrease of westerly winds over the Black Sea, and a greater influence of the Siberian anticyclone. The timing of the changeover from cooling to warming coincides with the regime shift in the Black Sea ecosystem.


2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Galina Surkova

AbstractAn initial investigation of recirculation is carried out for the coast of the Black Sea. The local mesoscale circulations (land-sea breezes, mountain and valley winds) in coastal areas are shown to be an additional risk factor in creating favorable conditions for air stagnation and accumulation of air pollutants in the surface atmosphere layer. Two types of annual recirculation patterns are revealed for northern and north-eastern coast of the Black Sea. Long-term changes in recirculation are investigated. It is shown that the recirculation parameter values remained quasistable until the mid-1970s. Since 1976–1977, steady intensification of recirculation in both winter and summer is identified.


1996 ◽  
Vol 32 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Adriana Cociasu ◽  
Liliana Dorogan ◽  
Christoph Humborg ◽  
Luci Popa

2019 ◽  
Vol 26 (6) ◽  
Author(s):  
A. I. Mizyuk ◽  
M. V. Senderov ◽  
G. K. Korotaev ◽  
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2019 ◽  
Vol 46 (1) ◽  
pp. 58-69
Author(s):  
V. L. Dorofeev ◽  
L. I. Sukhikh

Herein, we present a simulation of the dynamics of Black Sea ecosystems using a three-dimensional interdisciplinary model that assimilates satellite color scanner measurements. Calculations were performed for the fifteen years from 1998 and a set of 3-d biogeochemical fields of the Black Sea were generated on a regular grid with a discreteness time of 1 day. Analyses of core biogeochemical parameters of the marine ecosystem were then performed. The qualities of received fields were evaluated using comparisons with existing data from in situ measurements.


2019 ◽  
Vol 4 (4) ◽  
pp. 3-14
Author(s):  
G. V. Zuyev

Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) is one of the abundant species of fish in the Sea of Azov – Black Sea basin. Due to its large number sprat plays an extremely important role in the ecosystem of the sea, being an intermediate link between zooplankton and representatives of the highest trophic level – large predatory fish, dolphins, and birds. At the same time sprat is one of the important commercial fish in all the Black Sea countries, steadily being on the second place of catch volume in recent decades (after anchovy). The total catch reaches 100 thousand tons. Turkey and Ukraine are the main producing countries. Monitoring and forecast of biological state of sprat population with rising fishing intensity and climate changes are urgent tasks. The research subject of this article is the long-term (2000–2016) dynamics of biological (qualitative) parameters determining the population fecundity of Black Sea sprat in Crimean region, the current state of reproductive potential, and the conditions for its formation. The article is based on the results of own research. Parameters determining the population fecundity – the length-age structure of the spawning part population, the absolute individual fecundity, and the sex structure population (ratio between females and males) – were studied. In the long-term plan (in 2011–2016 compared with 2000–2004) the average length of spawning females decreased by 1.22 times (from 7.36 to 6.03 cm). It was accompanied by a decrease in the absolute individual fecundity by 2.39 times (from 13 625 to 5690 eggs). The numerical ratio between females and males decreased by 1.23 times (from 1.95 to 1.59). Simultaneously the sprat stock in the northern part of the Black Sea was reduced by more than 2.5 times (from > 500 thousand tons to < 200 thousand tons). As a result, the population fecundity of sprat in Crimean region decreased by more than 7 times (2.39 × 1.23 × 2.5). The conditions of sprat fishing in the northern part of the Black Sea (from the mouth of the Danube River to the Kerch Strait) were studied. They showed 2-fold decrease (from 251.9 thousand tons in 2000–2004 to 129.1 thousand tons in 2011–2016) in the total catch and more than 2.3-fold decrease (from 50.4 to 21.4 thousand tons) in average annual catch in this region. On the contrary, in the Crimean shelf the total catch at that time increased by 1.2 times (from 76.9 to 92.2 thousand tons), and its average annual value remained constant (15.4 thousand tons). While reducing the stock by 2.5 times, this means that the fishing pressure on the Crimean population increased 2.5 times. This fact suggests considering the factor of fishing as the main cause of its degradation. Validity of this version is confirmed by the fact of conjugacy (inverse connection) of interannual fluctuations between the catch and the length-age parameters of sprat in Crimean region in 2003–2013 previously found: catches over 15–16 thousand tons were accompanied by a next year decrease in the fish average length. Regulation of fishing is a necessary condition for preventing further degradation, for restoring and maintaining sustainable state of sprat population in Crimean region and its reproductive potential. The negative impact of natural (climatic and trophic) factors on the state of the population should be recognized as a secondary one. Local overfishing indicates indirectly the structuring of the commercial stock of Black Sea sprat, its division into a number of geographical aggregations (stock units), i. e. the presence of intraspecific differentiation.


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