The fate of river-borne floating marine litter in the coastal sea: a case study of flooding discharge from numerous small rivers in the northeastern part of the Black Sea

2020 ◽  
Author(s):  
Evgeniya Korshenko ◽  
Victor Zhurbas ◽  
Alexander Osadchiev ◽  
Pelagiya Belyakova
Keyword(s):  
Black Sea ◽  
Small Rivers ◽  
The Black Sea ◽  
Study Region ◽  
Marine Litter ◽  
Northeastern Part ◽  
Area Of Interest ◽  
Matter Transport ◽  
Coastal Sea ◽  
River Mouths

<p>This study is focused on delivery and transport of floating marine litter, which is carried by river discharge to coastal sea. This floating matter initially is contained in river plumes and its transport is governed by river plume dynamics. Despite the great importance of understanding the fate of floating marine litter (including plastic litter) in the sea, many aspects of its transport and accumulation remain unstudied. In this study we consider a large flood which happened in the northeastern part of the Black Sea in October 2018. A high resolution circulation model with a non-uniform horizontal grid (the grid bin length is decreased up to 200 m in a local area of interest) is applied to simulate transport of floating matter brought into the sea by overflowing rivers. The floating matter transport is modelled by horizontal advection of Lagrangian particles seeded in the mouths of main rivers of the study region in proportion to the actual river runoff. The particles that originated from different river mouths merge together on a horizontal velocity convergence line. These areas of accumulated marine litter remain stable during several days and are transported off the river mouths by a quasi-geostrophic alongshore current. However, some of the particles are trapped in the surf zone and form irregular contamination of the shoreline depending on local circulation features controlled by bottom topography and local wind forcing.  </p>

scholarly journals Small river plumes off the northeastern coast of the Black Sea under average climatic and flooding discharge conditions

Ocean Science ◽  
2017 ◽  
Vol 13 (3) ◽  
pp. 465-482 ◽  
Author(s):  
Alexander Osadchiev ◽  
Evgeniya Korshenko
Keyword(s):  
Black Sea ◽  
Line Source ◽  
Climatic Conditions ◽  
Small Rivers ◽  
The Black Sea ◽  
Intense Line ◽  
Study Region ◽  
Northeastern Part ◽  
The Impact ◽  
Heavy Rains

Abstract. This study focuses on the impact of discharges of small rivers on the delivery and fate of fluvial water and suspended matter at the northeastern part of the Black Sea under different local precipitation conditions. Several dozens of mountainous rivers flow into the sea at the study region, and most of them, except for several of the largest, have little annual runoff and affect adjacent coastal waters to a limited extent under average climatic conditions. However, the discharges of these small rivers are characterized by a quick response to precipitation events and can significantly increase during and shortly after heavy rains, which are frequent in the considered area. The delivery and fate of fluvial water and terrigenous sediments at the study region, under average climatic and rain-induced flooding conditions, were explored and compared using in situ data, satellite imagery, and numerical modeling. It was shown that the point-source spread of continental discharge dominated by several large rivers under average climatic conditions can change to the line-source discharge from numerous small rivers situated along the coast in response to heavy rains. The intense line-source runoff of water and suspended sediments forms a geostrophic alongshore current of turbid and freshened water, which induces the intense transport of suspended and dissolved constituents discharged with river waters in a northwestern direction. This process significantly influences water quality and causes active sediment load at large segments of the narrow shelf at the northeastern part of the Black Sea compared to average climatic discharge conditions.

scholarly journals Small river plumes off the north-eastern coast of the Black Sea under average climatic and flooding discharge conditions

2017 ◽  
Author(s):  
Alexander Osadchiev ◽  
Evgeniya Korshenko
Keyword(s):  
Black Sea ◽  
Line Source ◽  
Climatic Conditions ◽  
Small Rivers ◽  
The Black Sea ◽  
Study Region ◽  
The North ◽  
North Eastern ◽  
North Eastern Part ◽  
Heavy Rains

Abstract. This study is focused on the impact of discharge of small rivers on delivery and fate of fluvial water and suspended matter at the north-eastern part of the Black Sea under different local precipitation conditions. Several dozens of mountainous rivers inflow into the sea at the study region and most of them, except the several largest, have small annual runoff and limitedly affect adjacent coastal waters under average climatic conditions. However, discharges of these small rivers are characterized by quick response to precipitation events and can dramatically increase during and shortly after heavy rains which are frequent in the considered area. Delivery and fate of fluvial water and terrigenous sediments at the study region under average climatic and rain-induced flooding conditions were explored and compared using in situ data, satellite imagery and numerical modelling. It was shown that the point-source spread of continental discharge dominated by several large rivers during average climatic conditions can change to the line-source discharge from numerous small rivers situated along the coast in response to heavy rains. Intense line-source runoff of water and suspended sediments forms a geostrophic alongshore current of turbid and freshened water, which induces intense transport of suspended and dissolved constituents discharged with river waters in a north-western direction. This process significantly influences water quality and causes active sediment load at large segments of narrow shelf at the north-eastern part of the Black Sea as compared to average climatic discharge conditions.

Riverine transport of floating macro litter to the Southeastern Black Sea

2021 ◽  
Author(s):  
Ülgen Aytan ◽  
Çağan Şenyiğit ◽  
Yasemen Şentürk ◽  
Başak Esensoy
Keyword(s):  
Black Sea ◽  
Environmental Problem ◽  
Small Rivers ◽  
The Black Sea ◽  
Plastic Pollution ◽  
Effective Prevention ◽  
Marine Litter ◽  
Riverine Litter ◽  
Three Rivers ◽  
Riverine Transport

<p>Marine litter, especially plastic, is the fastest growing environmental problem in the Black Sea. Rivers are recognized as the major sources of litter in the basin, but information on the transport of litter by rivers is still limited. This study presents the first estimates of riverine floating macro-litter in the SE Black Sea (Turkey), based on monthly visual counting in three relatively small rivers between January and August of 2020. Plastic represented 99 % of the identified items with fragments (2.5–50 cm) (40.3 %) and shopping bags (26.2 %) being the most abundant items. Riverine litter fluxes median values varied between 35 and 96 items/hour in three rivers. Results show that small rivers can carry a considerable amount of plastic to the SE Black Sea. This calls for increased monitoring of riverine litter transport to develop effective prevention and removal strategies for tackling the problem of plastic pollution in the Black Sea.</p>

SITE-SPECIFIC EQUATIONS OF STATE FOR COASTAL SEA AREAS AND INLAND WATER BODIES

2017 ◽  
Author(s):  
Natalia Andrulionis ◽  
Natalia Andrulionis ◽  
Ivan Zavialov ◽  
Ivan Zavialov ◽  
Elena Kovaleva ◽  
...  
Keyword(s):  
Equation Of State ◽  
Black Sea ◽  
Water Samples ◽  
Equations Of State ◽  
Sea Water ◽  
Ionic Composition ◽  
Water Bodies ◽  
Aral Sea ◽  
The Black Sea ◽  
Coastal Sea

This article presents a new method of laboratory density determination and construction equations of state for marine waters with various ionic compositions and salinities was developed. The validation of the method was performed using the Ocean Standard Seawater and the UNESCO thermodynamic equation of state (EOS-80). Density measurements of water samples from the Aral Sea, the Black Sea and the Issyk-Kul Lake were performed using a high-precision laboratory density meter. The obtained results were compared with the density values calculated for the considered water samples by the EOS-80 equation. It was shown that difference in ionic composition between Standard Seawater and the considered water bodies results in significant inaccuracies in determination of water density using the EOS-80 equation. Basing on the laboratory measurements of density under various salinity and temperature values we constructed a new equation of state for the Aral Sea and the Black Sea water samples and estimated errors for their coefficients.

Hydrophysical and Hydrochemical Characteristics of the Sea Areas Adjacent to the Estuaries of Small Rivers of the Russian Coast of the Black Sea

2014 ◽  
Vol 54 (3) ◽  
pp. 293-308
Author(s):  
P. O. Zavialov ◽  
P. N. Makkaveev ◽  
B. V. Konovalov ◽  
A. A. Osadchiev ◽  
P. V. Khlebopashev ◽  
...  
Keyword(s):  
Black Sea ◽  
Small Rivers ◽  
The Black Sea ◽  
Hydrochemical Characteristics

scholarly journals Effect of Invasive Rhododendron ponticum L. on Natural Regeneration and Structure of Fagus orientalis Lipsky Forests in the Black Sea Region

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 603
Author(s):  
Zdeněk Vacek ◽  
Stanislav Vacek ◽  
Derya Eşen ◽  
Oktay Yildiz ◽  
Jan Král ◽  
...  
Keyword(s):  
Black Sea ◽  
Natural Regeneration ◽  
The Black Sea ◽  
Beech Forests ◽  
Study Region ◽  
Fagus Orientalis ◽  
Black Sea Region ◽  
Rhododendron Ponticum ◽  
Tree Layer ◽  
Fagus Orientalis Lipsky

Biological invasions threaten global biodiversity and forest ecosystems; therefore, it is necessary to use appropriate strategies for combating the spread of invasive species. Natural regeneration of eastern beech (Fagus orientalis Lipsky) is considerably limited by an aggressive invasive shrub, pontic rhododendron (Rhododendron ponticum L.), in the Black Sea Region of Turkey. Therefore, the future character of the region’s forests is uncertain. The aim of this research was to evaluate the structure of beech forests with different management regimes of rhododedron and to determine the interaction among tree layer, rhododendron cover, and natural regeneration in Düzce Province using the FieldMap technology. The following variants of forests were compared: without intervention (control) and three and six years after rhododendron clearance. The results showed that tree density ranged between 175–381 trees ha−1 and stand volume between 331–589 m3 ha−1. The horizontal structure of the tree layer was mostly random, and the spatial pattern of natural regeneration was aggregated. Recruit density and height in the beech stands were significantly differentiated due to the influence of presence or absence of invasive rhododendron. Rhododendron cover ranged between 81%–97%, and woody stems amounted to 72,178–86,884 ha−1 in unmanaged forests. Canopy in the overstory did not have a significant effect on the density of regeneration and rhododendron cover. Tree layer had a significant negative influence on natural regeneration within a 4 m radius on the plots without rhododendron. However, on the plots with dense rhododendron cover, tree layer had a positive influence on regeneration within a 1.5 m radius. Natural regeneration density was significantly higher when rhododendron was cleared than the plots without intervention. On the plots without woody clearance, there was an insufficient regeneration (113–619 recruits ha−1); however, they had higher mean height compared to the sites without rhododendron. After three and six years of rhododendron clearance, the numbers of recruits in natural regeneration were 63,981 ha−1 and 105,075 ha−1, respectively. In conclusion, invasive spread of rhododendron was a limiting factor of the prosperous regeneration and tree species diversity, and manual clearance of rhododendron is recommended in managed beech forests of the study region.

ROLE OF MOUTH PROCESSES IN THE DYNAMICS OF ACCUMULATIVE FORMS IN COASTAL ZONE OF BLACK SEA (WITHIN THE RUSSIAN SECTOR)

2018 ◽  
Author(s):  
М. Исупова ◽  
M. Isupova
Keyword(s):  
Black Sea ◽  
River Mouth ◽  
The Black Sea ◽  
Special Role ◽  
Coastal System ◽  
System A ◽  
Russian Sector ◽  
Mouth Bars ◽  
River Mouths

The processes in the river mouth areas play a special role in the formation and dynamics of coastal accumulative forms. The experience of Russian and foreign specialists on investigations of river mouths shows a modern intensification of sea impact on the river deltas in the world and enhance the abrasion of their delta coastlines. These processes show a trend of transformation of different mouths from the fluvial-dominated objects to the marine-dominated objects. A striking example of this process is the variability of the mouth fan, which has a complicated structure, and the mouth bars. In most cases, the structure of the mouth fan presents several successive layers. There are the following 1) abovewater and submarine sand layers; 2) layer of silty sediments of the sea slope of the mouth fan; 3) gently sloping layers of clay, component the foot of the mouth fan; 4) layer of shelf sand, not related to the formation of mouth fan. Each of these layers is characterized by a specific size and composition of sediments. Under intensification of abrasion of the mouth accumulative forms (accordance with the stage of this abrasion), the sediments significantly differed by composition, can be penetrate in the lithodynamic coastal system. A rather complex topography of the underwater slope rugged canyons is typical for the Russian coast of the Black Sea. Through these canyons, sediments, entering the river mouth area and playing an important role in the dynamics of coastal accumulative forms, can be delivered to the depths. These depths exclude of their return.

SITE-SPECIFIC EQUATIONS OF STATE FOR COASTAL SEA AREAS AND INLAND WATER BODIES

2017 ◽  
Author(s):  
Natalia Andrulionis ◽  
Natalia Andrulionis ◽  
Ivan Zavialov ◽  
Ivan Zavialov ◽  
Elena Kovaleva ◽  
...  
Keyword(s):  
Equation Of State ◽  
Black Sea ◽  
Water Samples ◽  
Equations Of State ◽  
Sea Water ◽  
Ionic Composition ◽  
Water Bodies ◽  
Aral Sea ◽  
The Black Sea ◽  
Coastal Sea

This article presents a new method of laboratory density determination and construction equations of state for marine waters with various ionic compositions and salinities was developed. The validation of the method was performed using the Ocean Standard Seawater and the UNESCO thermodynamic equation of state (EOS-80). Density measurements of water samples from the Aral Sea, the Black Sea and the Issyk-Kul Lake were performed using a high-precision laboratory density meter. The obtained results were compared with the density values calculated for the considered water samples by the EOS-80 equation. It was shown that difference in ionic composition between Standard Seawater and the considered water bodies results in significant inaccuracies in determination of water density using the EOS-80 equation. Basing on the laboratory measurements of density under various salinity and temperature values we constructed a new equation of state for the Aral Sea and the Black Sea water samples and estimated errors for their coefficients.

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