Сучасна реседиментація донних відкладень Дунайського району Чорного моря
Альтернативна назва
Modern resedimentation of bottom sediments of the Danube district of the Black Sea
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Дата
2025
Науковий керівник
Укладач
Редактор
Назва журналу
ISSN
2303-9914
E-ISSN
2415-315X
Назва тому
Видавець
Одеський національний університет імені І. І. Мечникова
Анотація
У статті представлено дослідження вторинного замулення донних відкладів у північно-західній частині Чорного моря, зокрема в Дунайському районі. Розглядаються причини та наслідки цього процесу, включаючи вплив річкового стоку, гідрологічних фронтів та господарської діяльності людини, такої як дампінг і днопоглиблювальні роботи. Описано методи відбору проб та наведено результати екологічного моніторингу за період 2019–2020 рр., з оцінкою стану замулення, його поширення та потужності шару намулку на різних дослідницьких станціях.
Problem Statement and Purpose. The northwestern part of the Black Sea is undergoing significant changes in the composition and structure of bottom sediments, which is manifested in secondary siltation or resedimentation. This phenomenon is a consequence of the complex interaction of natural and anthropogenic factors, but their complex impact and regional features require further study. An assessment of the scale and dynamics of this process in the environmentally sensitive Danube region, which is subject to significant anthropogenic load, is especially relevant. The main objective of the study is to determine the boundaries of the spread of secondary siltation of bottom sediments in the Danube region of the Black Sea based on expeditionary observations of the UkrNCEM for the period 1998–2020. The object of the study is modern Holocene bottom sediments of the Dzemetyn Stage of the northwestern part of the Black Sea and the coastal zone of the Danube River. In the process of ecological research in the coastal zone of the Danube, the task was set to assess the level of siltation, its distribution, thickness, color and consistency. It was established that secondary siltation in the northwestern part of the Black Sea is caused by changes in river runoff (volume and composition) under the influence of river regulation and industrial and agricultural activities. Hydrological fronts play an important role in coastal zones, where intensive sedimentation of suspended matter occurs. Anthropogenic activities, including dredging, soil dumping and other types of management, cause specific pollution and disruption of ecosystems. In the Danube littoral, the phenomenon of resedimentation has been recorded both in the approach channel and in the open part of the sea, with the most intensive siltation in the area of soil dumping. The study confirms the significant influence of both natural and anthropogenic factors on the processes of secondary siltation of bottom sediments in the northwestern part of the Black Sea, especially in the Danube region. The obtained data on the distribution and characteristics of siltation are important for assessing the ecological state of the region and developing measures for its conservation. Data & Methods. The research presented in the article was carried out by the author as part of the scientific group of the National State Educational Institution “Ukrainian Scientific Center for Marine Ecology” within the framework of the research project “Basic assessment and determination of Good Ecological Status (GES) of the marine environment of the Black Sea within the exclusive maritime economic zone of Ukraine”. Sampling was carried out within the Danube Environmental Monitoring Range at 12 monitoring stations in the sea depth range from 4.5 m to 26 m four times from November 2019 to October 2021. Samples of the surface layer of marine sediments were obtained using a bottom scoop DC-0.1 with a bottom substrate capture area of 0.1 m². After lifting the device on board, a detailed description of the obtained material was carried out, including the type of sediment, its color, consistency, presence of marine organisms (fauna) and odor. The studies included measurements of surface and bottom water temperatures, determination of the extent of siltation of bottom sediments, and assessment of water transparency. An analysis of the siltation state of marine bottom sediments was conducted depending on the thickness of the silt layer. In this study, the criterion was adopted, according to which a silt thickness of less than 5 mm indicates a satisfactory bottom condition, and a thickness of more than 5 mm indicates an unsatisfactory one. Results. The conducted studies revealed a periodic deterioration of the ecological condition of the Black Sea bottom within the Prydunaysky landfill due to the accumulation of silt. In November 2019, an area with a significant silt thickness (up to 50 mm) was recorded, which indicated a poor condition. Nine months later, in August 2020, the situation improved significantly – the area of distribution and silt thickness decreased. However, in May 2021, the condition of the bottom deteriorated again, with a repeated increase in silt thickness in the same areas of the western part of the landfill. The autumn assessment in October 2021 showed a decrease in silt thickness throughout the area, although its presence became background. Analysis of silting dynamics at the same stations revealed an area in the western part of the landfill with periodic activation of re-sedimentation processes and poor ecological condition of the bottom. The rest of the territory was characterized by a satisfactory condition with temporary and acceptable manifestations of resedimentation.
Problem Statement and Purpose. The northwestern part of the Black Sea is undergoing significant changes in the composition and structure of bottom sediments, which is manifested in secondary siltation or resedimentation. This phenomenon is a consequence of the complex interaction of natural and anthropogenic factors, but their complex impact and regional features require further study. An assessment of the scale and dynamics of this process in the environmentally sensitive Danube region, which is subject to significant anthropogenic load, is especially relevant. The main objective of the study is to determine the boundaries of the spread of secondary siltation of bottom sediments in the Danube region of the Black Sea based on expeditionary observations of the UkrNCEM for the period 1998–2020. The object of the study is modern Holocene bottom sediments of the Dzemetyn Stage of the northwestern part of the Black Sea and the coastal zone of the Danube River. In the process of ecological research in the coastal zone of the Danube, the task was set to assess the level of siltation, its distribution, thickness, color and consistency. It was established that secondary siltation in the northwestern part of the Black Sea is caused by changes in river runoff (volume and composition) under the influence of river regulation and industrial and agricultural activities. Hydrological fronts play an important role in coastal zones, where intensive sedimentation of suspended matter occurs. Anthropogenic activities, including dredging, soil dumping and other types of management, cause specific pollution and disruption of ecosystems. In the Danube littoral, the phenomenon of resedimentation has been recorded both in the approach channel and in the open part of the sea, with the most intensive siltation in the area of soil dumping. The study confirms the significant influence of both natural and anthropogenic factors on the processes of secondary siltation of bottom sediments in the northwestern part of the Black Sea, especially in the Danube region. The obtained data on the distribution and characteristics of siltation are important for assessing the ecological state of the region and developing measures for its conservation. Data & Methods. The research presented in the article was carried out by the author as part of the scientific group of the National State Educational Institution “Ukrainian Scientific Center for Marine Ecology” within the framework of the research project “Basic assessment and determination of Good Ecological Status (GES) of the marine environment of the Black Sea within the exclusive maritime economic zone of Ukraine”. Sampling was carried out within the Danube Environmental Monitoring Range at 12 monitoring stations in the sea depth range from 4.5 m to 26 m four times from November 2019 to October 2021. Samples of the surface layer of marine sediments were obtained using a bottom scoop DC-0.1 with a bottom substrate capture area of 0.1 m². After lifting the device on board, a detailed description of the obtained material was carried out, including the type of sediment, its color, consistency, presence of marine organisms (fauna) and odor. The studies included measurements of surface and bottom water temperatures, determination of the extent of siltation of bottom sediments, and assessment of water transparency. An analysis of the siltation state of marine bottom sediments was conducted depending on the thickness of the silt layer. In this study, the criterion was adopted, according to which a silt thickness of less than 5 mm indicates a satisfactory bottom condition, and a thickness of more than 5 mm indicates an unsatisfactory one. Results. The conducted studies revealed a periodic deterioration of the ecological condition of the Black Sea bottom within the Prydunaysky landfill due to the accumulation of silt. In November 2019, an area with a significant silt thickness (up to 50 mm) was recorded, which indicated a poor condition. Nine months later, in August 2020, the situation improved significantly – the area of distribution and silt thickness decreased. However, in May 2021, the condition of the bottom deteriorated again, with a repeated increase in silt thickness in the same areas of the western part of the landfill. The autumn assessment in October 2021 showed a decrease in silt thickness throughout the area, although its presence became background. Analysis of silting dynamics at the same stations revealed an area in the western part of the landfill with periodic activation of re-sedimentation processes and poor ecological condition of the bottom. The rest of the territory was characterized by a satisfactory condition with temporary and acceptable manifestations of resedimentation.
Опис
Ключові слова
Чорне море, Дунайський район, реседиментація, дампінг, Black Sea, Danube region, resedimentation, dumping
Бібліографічний опис
Золотарьов М. Г. Сучасна реседиментація донних відкладень Дунайського району Чорного моря / М. Г. Золотарьов // Вісник Одеського національного університету. Географічні та геологічні науки. – 2025. – Т. 30, вип. 1(46). – С. 251–261.
УДК
551.466.8:551.3.053(262.5:498.282.54)