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Processes of Natural Self-Cleaning of Small Watercourses with Increasing Anthropogenic Load in the Dniester River Basin

Hnativ Roman, Cherniuk Volodymyr, Khirivskyi Petro, Kachmar Natalia, Lopotych Natalia, Hnativ Ihor

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

12--18

EN

Small river basins are complex self-regulatory systems, as well as indicators of the state of the environment due to the level of anthropogenic pressure. Since any changes in the regime of small rivers are reflected in the entire hydrographic chain, the problem of estimating the anthropogenic load on small rivers of Ukraine is relevant for modern hydrochemistry and hydroecology. The main sources of water pollution are industrial and domestic effluents, which increase the inflow of pesticides, heavy metal ions, etc. Aquatic ecosystems of small rivers are subject to intense mechanical and biochemical effects, and about 80% of pollutants are washed into water bodies. Water bodies located on the territory or near large cities and urban areas are particularly exposed to man-made pollution. In the territory of the Dniester river basin, natural landscapes are maximally preserved in comparison with other regions of Western Ukraine, but in modern conditions we observe an increase in the negative anthropogenic impact on the quality of natural waters. Hydrodynamic barriers or hydrodynamically active areas (HAA) of mountain rivers, which are significantly saturated with oxygen in the water flow, which activates the processes of biochemical and biological self-cleaning of natural waters, are important to increase the efficiency of self-purification processes. Natural biological cleaning of pollutants in small rivers is highly effective due to the overgrowth of aquatic vegetation. The aim of the work was to establish the ability of the aquatic ecosystem of a small river to self-purify on the basis of hydrochemical indicators of water quality. The compliance with sanitary and hygienic requirements of hydrochemical indicators of Kolodnytsia river water of the right tributary of the Dniester was analyzed and possible regularities of their changes were established, as well as the main factors of anthropogenic impact on a small river and the possibility of laboratory modeling of such rivers. It was found that in the Kolodnytsia River the processes of self-cleaning are quite active, which are caused by the hydrological characteristics of the river and the presence of hydrodynamically active areas in the foothills of the basin. Therefore, at present there is no steady excess of pollutants relative to the MPC.

2

Development of Channel Processes and the Need to Forecast Deformations of the Stryi Riverbed

Hnativ Ihor, Balkovskyi Volodymyr, Cherniuk Volodymyr, Panas Natalia, Korinec Yuri, Yakhno Oleh, Hnativ Roman

Journal of Ecological Engineering

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2022

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Vol. 23, nr 5

187--195

EN

Deformations of the channel are a consequence of the development of denudation processes in the basin area, increase in the volume of solid runoff and deposition of debris of the rock, its fractional redistribution in the channels, which especially increase during floods and flooding. They cause changes in the hydrological regime and structure of the river system, the destruction of residential and commercial buildings, as well as the infrastructure in the floodplain. Trends, magnitudes and intensity of deformations of riverbeds are formed by a complex of natural and man-made factors. Neglecting the planned and high-altitude displacements of riverbeds often leads to unpredictable consequences. Washing the shore can cause a gas or oil pipeline to rupture, leading to a strong explosion and fire, as well as oil pollution and environmental damage. Channel processes are associated with the washing of bridge piers, power lines, significant material losses and even human casualties during floods and flooding. The aim of the work is to analyze the development of channel processes in the basin of the river Stryi and forecast the deformation of its channel. The results of the analysis show that the riverbeds of Prykarpattia are very unstable and are characterized by intense erosion of the banks and bottom, which is caused by the influence of various factors. It is a man-made activity that includes the development of gravel quarries in floodplains and riverbeds and their straightening, runoff regulation, changes in forestry and land use. Natural factors, such as climate change and water runoff, etc., are also affected. It was found that the bed of the river Stryi does not have a stable shape, significantly changed the configuration, significantly reduced multi-sleeved and increased its straightness, and in some places the river changed its position by 60–80 meters. Restoration works carried out in some parts of the riverbed during this period were not effective enough. Water in different parts of the riverbed washes the shores, which causes dangerous landslides that occur directly near the riverbed. In these areas, it is necessary to more effectively carry out measures to regulate runoff and restore shore protection.

3

Monitoring of horizontal displacements and changes of the riverine area of the Dniester River

Shevchuk Volodymyr, Burshtynska Khrystyna, Korolik Iryna, Halochkin Maksym

Journal of Water and Land Development

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2021

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no. 49

1--15

EN

The article discusses the monitoring of horizontal displacements of the channel of Dniester, the second largest river in Ukraine, based on topographic maps, satellite images, as well as geological, soil and quaternary sediment maps. Data processing has been carried out using the geographic information system ArcGIS. The monitoring over a 140-year period (1874–2015) has been performed at the river’s transition from a mountainous to plain terrain on the 67 km section of the river. During this period, maximum displacements in the study area were 590–620 m. The research examines water protection zones needed for channel displacements. The article describes the monitoring methodology and analyses changes over a period of 18 years (2000–2018). The analysis includes the anthropogenic influence on the channel in the monitoring area. Results of the research may be useful for construction and cadastral works related to the channel in the area concerned, as well as for water management.

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Results of hydrological studies and channel analysis of the Ganges (Padma) River at the construction site of the “Rooppur” NPP

Zavadsky A. S., Botavin D. V., Golovlev P. P., Mikhailova N. M., Morozova E. A., Promakhova E. V., Turykin L. A.

Geography and Tourism

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2018

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Vol. 6, No. 1

41--53

EN

This work presents the results of research on channel processes in the Padma River (Republic of Bangladesh) at the construction site of the “Ruppur” Nuclear Power Plant (NPP). The fluvial characteristics of the Padma River were presented, including: the water outflow regime, characteristics of anthropogenic impact on the river outflow and assessment of the present state of the channel and floodplain. The research was conducted based on field expeditions, during which data on morphology, dynamics, hydrological and hydraulic conditions for the formation of the floodplain-channel complex were collected. Moreover, the water discharges and suspended sediments, as well as the longitudinal profiles of the water level and the channel morphology were measured. The presented research has shown that comprehensive and planned regulation of selected sections of rivers could lead to the channel stabilization and support the rational use of water resources for different purposes, e.g. power plants, municipal purposes, etc. Moreover, detailed research on channel deformation in selected areas indicated the major role of natural factors (geological structure, the type of sediments delivered to the river, vegetation cover, etc.) in the past and present fluvial processes.

5

Morphological features of river channels and floodplains in the Far East of Russia under various natural conditions

Chernov A. V.

Geography and Tourism

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2018

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Vol. 6, No. 1

55--59

EN

Geographical analysis of river channel processes in rivers located along the meridional transect, running from the Arctic Ocean coast to Tibet and the East China Sea, confirmed that fluvial processes dominate in the formation of morphology and dynamics of river channels and floodplains in all natural zones and under different conditions of channel deformation development. However, even a small disturbance in “climate” conditions by other exogenous geomorphological processes changes the morphology and dynamics of channels and floodplains as well as the dynamics of fluvial processes. The effect of zonal factors depends on the size of a given river and is more pronounced in medium and small rivers than the large ones. Furthermore, the effect of zonal factors on the processes of river channels and floodplains depends on specific environmental conditions of the climate zones: the more extreme the manifestation of certain climatic phenomena, the more pronounced they are in the morphology and dynamics of river channels and floodplains.

6

Channel processes of the Ob River and the use of the river for water transport purposes

Ruleva S. N.

Geography and Tourism

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2018

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Vol. 6, No. 1

95--98

EN

The Ob River is one of the largest rivers in Russia and currently the most important traffic route in Western Siberia. The paper presents the history of water transport on the Ob River against the background of channel processes limiting the navigation on the river. The heterogeneity of the Ob River is determined by specific features of the channel processes and the stability of the riverbed, morphological types of the channel, the nature of deformations, long-term and seasonal changes of riffles and sections of the channel characterized by the presence of riffles. The main measures aimed at improving the navigational conditions of the Ob River include dredging of riffles, construction of dams and bypass channels.

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Channel processes and its management on navigable rivers

Chalov R. S.

Geography and Tourism

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2018

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Vol. 6, No. 1

61--67

EN

Inland waterways are the sector of the economy that is most dependent on channel processes and their management to ensure safety and favourable conditions for navigation. The main goals of the river channel management are to improve the waterways in terms of navigation and, at the same time, to preserve the rivers as natural sites. The presented study defines the criteria for classification of rivers and river sections according to the complexity of channel processes, their forecasting and management. The classification of rivers as waterways has been provided based on the complexity of channel process management and designing of dredging works and investments aimed at improving the navigation conditions. Examples of this approach are given based on specific rivers of Russia.

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Effects of width channel increase in the formation and evolution of sandbars (riffles)

Mikhailova Nadezhda

Geography and Tourism

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2017

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Vol. 5, No. 2

57--66

EN

The paper presents the morphology and the long-term regime of riffles formed in the local widening of river channels: the Ob, the Northern Dvina, and the Ganges. Navigation maps for the last 120 years, detailed channel plans for the last 60 years as well as satellite images from 1977 and further were used to study the long-term regime of riffles. Five types of riffles are distinguished in the widening of river channels. Each type of riffles has a specific regime and a characteristic period of long-term reformations, with both the regime and the period being controlled by local surroundings of riffles. The presented study of the long-term regime of riffles and its relationship with local morphological conditions could be useful to optimize dredging works and, as a consequence, help to preserve optimal conditions of waterways.

9

Monitoring of the riverbed of river Dniester using GIS technologies

Burshtynska K., Halochkin M., Tretyak S., Zayats I.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2017

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Vol. 29

25--36

EN

The paper analyses the causes of riverbeds shifts and meandering of Dniester. Among such reasons are mostly climatic, geographical and anthropogenic factors, such as frequent floods semi-stable rocks and soils, deforestation and removal of gravel and sand material from the river bed. The research is carried out on the lowland of the Dniester along the 100 km section over the 100 years period. Topographic maps (1910, 1923, 1976 years), and satellite images from Landsat 5 (1986) Landsat 7 (2000) Sentinel (2017) and special soil maps was taken as initial information. The Dniester meandering research shows significant correlation in horizontal riverbed movements for the periods from 1910 till 1986 and from 1984 till 2017. Correlation rate variate within the limits 0.97 – 0.99 respectively that corresponds to the almost full dependence in the riverbed displacement configuration. Beside that the maximum horizontal deviations can reached up to 800 meters. In addition, it was revealed that sediment processes caused significant increase in the area of the river islands from 1910 to 1976 by 2.4 times, and from 1976 to 2017 the island areas somewhat reduced. Nearly the largest island River channel is divided into two branches. Sinuosity coefficient is 2.3 over the test site. The analysis of soil maps shows prevailing bleached soils and loamy on alluvial deposits soils in areas with highest sinuosity coefficient.

PL

Za główne przyczyny przemieszczenia się i meandrowania koryta rzek uznaje się zjawiska klimatyczne, a także czynniki geograficzne i antropogeniczne. Częste powodzie, określone rodzaje skał i gruntów, wylesienia i wymywanie żwiru i piasku z łożyska powodują przemieszczenie rzeki. Prezentowane badania przemieszczeń dotyczą równinnej części rzeki Dniestr. Analiza została przeprowadzona na odcinku rzeki długości około 100 km i dotyczy okresu minionych 100 lat. Do badań wykorzystano mapy topograficzne z lat 1910, 1923, 1976 i zdjęcia satelitarne z satelity Landsat 5 (1986), Landsat 7 (2000) i Sentinel (2017), a także mapy gruntów. Z badań meandrowania rzeki Dniestr w okresach 1910-1986 i 1984-2017 określono związki korelacyjne między przemieszczeniami sytuacyjnymi, które wyrażone w formie współczynnika korelacji wynoszą odpowiednio 0.99 i 0.97, co świadczy o prawie całkowitym związku kształtów łożysk. Jednocześnie wyjaśniono że maksymalne przemieszczenia łożyska rzeki na odcinkach 1 i 2 wynoszą blisko 800 m, a na odcinku 5 do 100 m. Wyjaśniono, że zwiększenie niesionych osadów spowodowało w latach od 1910 do 1976 znaczny wzrost powierzchni wysp (około 2,4 razy), a w latach od 1976 do 2017 powierzchnia wysp zmniejszyła się, jednak w miejscu największej wyspy koryto podzieliło się na dwa rękawy. Ogółem krętość koryta na badanym fragmencie wynosi 2.3, co świadczy o tym że koryto jest meandrujące. Analiza mapy gruntów w miejscach maksymalnego meandrowania wskazuje, że głównymi typami gruntów są gleby łąkowe bielicowe i oglejone na złożach naniesionych.

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Wykorzystanie metod geoinformacyjnych w badaniach morfodynamiki koryta Wisły w Warszawie

Falkowski T., Ostrowski P.

Przegląd Geologiczny

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2015

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Vol. 63, nr 3

186–-194

EN

Prerequisite for rational river valleys management is estimation of its evolution processes causes and directions. Such analysis requires from geologist great number of different information, acquisition of which is very often associated with difficulties resulting (for instance) from channel zone inaccessibility. Besides accuracy in location of the observation points such works require also ability in registration of environment changes during short observation periods (e.g. on the base of subsequent measurement campaigns results) as well as during long periods (e.g. comparison of the topographic or remote sensing archival data ). The perfect tool for such purposes, which is capable to integrating various research results are geographic information systems. In the regulated, downtown section of the Warsaw Vistula channel since the 60s of the last century to the early XXI century was recorded a steady decline in the level of the medium and low water flow. This process became a threat for the channel zone infrastructure. At the same time above and below this channel section, in the zone less equipped with the hydro-technical structures the process of aggradation was observed. This leads to increase of flood risk. The paper presents results of investigations, which were conducted in the Vistula River channel zone in Warsaw. During the research it was found that the reason for a particular channel environment behaviour in reaction on the management is the channel geology. In the narrow, regulated downtown channel section the contemporary alluvia substrate (built up with erosion resistant deposits) creates morphologically diverse protrusion. Upstream and downstream of that channel section the roof of alluvia substratum lowers. Lack of possibilities to deepening channel during the high waters passage in downtown narrowed channel reach affects the higher flow speeds and creates conditions of sediment transit . Shallow position of erosion resistant deposits floor affects also the thalweg course. Beyond the culmination of substratum Vistula represents the wild river, overloaded by alluvia.