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Winter conditions of low air temperature cause development of ice phenomena at rivers and reservoirs, creating often problems in their exploitation. There is a need to continuously monitor the spatial extension of ice phenomena and their different forms. Local water authority (RZGW Warszawa) prepares for rivers under their administration a daily reports on ice conditions in winter. Ice reports are prepared from visual inspection of the RZGW personnel visiting selected sections of the river course. This is specially problematic in holidays and weekends when usually data from observations are missing. In this study it is tested application of microwave remote sensing data from Sentinel-1 platform to observe the development and recession of the ice cover at the Dębe reservoir in winter 2017. Satellite Sentinel-1 radar images are distributed by the European Space Agency (ESA) on the open access policy. These are two satellites A and B which every 2 days collect images in SAR active remote sensing technique. Dębe reservoir was created in 1963 by closing by the barrage Narew river below its confluence with Bug river. Maximum water head is 7.10 m, and average 6.8 m. Area of the reservoir is 30.3 km2 average discharge of Bug river at Wyszków gauge is 162 m³ ·s⁻¹, and Narew river at Zambski Kościelne gauge 139 m³ ·s⁻¹. Retention time of water in the reservoir is 3–4 days. Comparison of the average water temperature at gauge Zambski Kościelne and Wyszków from the winter half-year of the period 1963–1981 shows the increase of water temperature by 0.5–1 C after the year 1972 when Ostrołęka power station was put in to operation.. This difference in the temperature between Narew and Bug rivers is reflected by the ice conditions at the end of winter season. Sentinel-1 SAR instrument emits electromagnetic wavelength of 6 cm (C band), and are use two polarizations VH and VV. Using SNAP program geometric correction and color composite was created for selected images at the beginning and end of ice cover at Dębe reservoir on Narew river, covering period January 5-March 6, 2017. It has been found that interpretation of the Sentinel-1 images is most problematic if we want to detect boundary between open calm water and new fast ice. The flow of pancake ice on January 5, 2017 had been recorded and the pattern of ice distribution compared to flow lines calculated by the hydrodynamic CCHE2D model. Result of the hydrodynamic modeling shows circulation pattern in the widest part of the reservoir where are also the most favorable conditions for lake type of ice cover formation. End of ice cover is represented by the image of February 26, 2017 which shows the Narew river free from ice due to higher temperature of the water. Relatively simple visual interpretation of the Sentinel-1 VH and VV images can by used in the study of ice phenomena on major rivers and lakes.
Here are presented results of studies on vertical and horizontal migration of strontium 90Sr isotope in soil systems of Bug river valleys. Mean radioactivity of strontium in these soils was 26.15 ± 22.2 Bq/kg. Atmospheric precipitation of strontium on this area was 0.35 kBq/m2/cm. Radioactivity in soil profiles ranged from 17 to 130 Bq/m2/cm and the isotope was detected even at 30 cm depth. Some tendency to vertical migration of strontium towards the river was noticed. Obtained results were compared with concentrations of calcium and strontium in the soil. Any clear influence of these elements on the migration of strontium 90Sr was noticed.
The aim of the present study was to describe the diversity and abundance of the mollusc communities in long and diverse series of riparian water bodies (59 in total) and to compare them with previous (two years before) studies based on much shorter series of sites (21 in total). An attempt was made to check whether the previous analysis of mollusc groupings is suitable to the classification of the riparian sites of a large area. The studies were carried out in the years 2004–2006 in left-bank part of the valley between 53 and 152 km of the course of the lowland medium sized natural river (Bug River, Eastern Poland) in 59 water bodies differing as regards size (from about 0.01 to a few ha), location in the valley, hydrological regime and successional stage. The samples were collected from the bottom (with dredge) and from macrophytes. The high species richness and diversity were found within the study area despite that the natural floodplain fragments were quite small (about 10% of the whole investigated fragment of the river valley). 52 mollusc species were noted: 36 snails and 16 bivalves (over 50% more than in the preliminary series). Relatively rich malacofauna existed in larger and younger water bodies, as well as in some temporary ones, but located in the active floodplain. Species diversity of individual habitats was comparable to that reported from the earlier study (Jurkiewicz-Karnkowska 2006), i.e. H’ values amounted to 2–3 in most cases. However, there were more cases where H’ values exceeded 3, as well as H’ values were higher at larger scale, i.e. site groups and the total study area (3.5–4.5). The most common species (F≥ 50%) within the investigated area were Lymnaea stagnalis, Bithynia tentaculata, Planorbarius corneus, Anisus vortex, Radix balthica and Viviparus contectus. The most frequent species usually constituted significant components of mollusc communities of individual water bodies. The only species with percentages exceeding 10% of total mollusc abundance at the scale of the study area were P. corneus and L. stagnalis. The abundance of molluscs was of the order of several to a few hundred individuals per sample (0.5–1 m2 of bottom). Basing on the occurrence of molluscs in the investigated habitats I–V groups of water bodies were distinguished applying multivariate analysis. They differed in abundance, dominance pattern and diversity of malacocoenoses, as well as frequencies of individual species. Especially high distinctness of malacocoenoses of small temporary water bodies was found.
The presented paper analyses the occurrence of dragonflies in the left-bank (Polish) part of the Bug River valley between Włodawa and Kodeń (65 km of the river course, 51°32’–51°55’ N, 23°31’–23°38’ E). In total, 40 species were recorded. The key sites for dragonflies were oxbow lakes, the Bug River and its tributaries. Species diversity was found to be relatively low due to a lack of peat lands and dystrophic waters, as well as strong astatism of small water bodies. The effects of strong water pollution in the Bug River were evident. The species composition of dragonflies was typical, but densities of Gomphidae (particularly Ophiogomphus cecilia ) suggested an adverse state of the environment. This is caused by surface runoffs of agricultural wastewater in Poland, but also by strongly polluted rivers in the territory of Ukraine. The study includes a review of earlier research conducted in the upper course Bug River valley. Considering both the old and new data, 54 dragon fly species were recorded in the Middle Bug River valley between Gołębie and Kodeń (246 km of the river course at the border of Poland with Ukraine and Belarus). It is an area of high importance for the protection of dragonflies in terms of species diversity and species assemblages.
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Subject and purpose of work: The article describes a new subject of research into the history of economic thought, the international Pribuzhie region. The article discusses the history of the rise and development of economic science in the Pribuzhie region from the 8th to the 21st century, which is the subject of research. The aim of the article is to present a new perspective on the subject of research as well as the characteristics of the process of economic science in the Pribuzhie region. Materials and methods: The article uses a conventional method, which is a collection of historical, hilosophical and economic methods of cognition, on the basis of which, in the context of a scientific program, the past of economic thought and relevant doctrines are examined, and their content is described. Results: The various historical stages in the development of the economic thought of the Pribuzhie region are described, as well as new, unpublished facts relating to individual economic doctrines. Conclusions: Political activity and public administration activities should involve economic education, which defines the essence of economic policy, its objectives and ways of realization in the practical sphere.
The present study aimed at describing composition, species richness, dominance patterns and diversity of mollusc communities as well as frequency of individual species within selected water bodies of the valley of large Polish lowland river (lower Bug River). Suitability of molluscs in the ordination of the investigated habitats was evaluated. The studies were carried out in the years 2003–2004 in left-bank part of the valley between 2.5–6.5 and 90–107 km of the river course in 21 water bodies heterogenous as regards size, location and successional stage. The dredge was used. 34 mollusc species were found: 23 snails and 11 bivalves. At individual sites from 2 to 15 species were noted (4 – 18 including molluscs found only as empty shells). Relatively rich malacofauna existed in larger water bodies in comparison with small stagnant and isolated ones located outside the embankment. Malacocoenoses of the investigated habitats exhibited considerable species diversity (H’ = 2–3 in most habitats). Lymnaea stagnalis, Bithynia tentaculata, Planorbarius corneus and Viviparus contectus were the most frequent species (F≥ 50%). These species as well as moderately frequent ones constituted significant components of mollusc communities of individual water bodies. Frequencies and dominance patterns of molluscs inhabiting younger and older water bodies distinctly differed. The abundance of molluscs was mostly of the order of several to a few dozen individuals per sample (0.5–1 m² of bottom). Principal component analysis and classification (PCCA) basing on the occurrence of molluscs expressed as the classes of abundance enabled to distinguish 4 groups of water bodies, among which 2 were more distinct. The comparison of malacofauna of these two groups exhibited significant difference in frequencies. Species (S) and percentage (Psc) similarities among malacocoenoses of the investigated water bodies were generally weak or moderate, which presumably results from isolation among majority of them. More cases of high values of similarity indices were found within the group of small and shallow water bodies in comparison with larger and deeper ones. This may result mainly from higher habitat homogeneity at later stages of hydrarch succession. Generally higher species than percentage similarity was observed indicating the differences in dominance relations among sites with similar composition of malacofauna.
Studies of the contents of gamma emitters in samples of water and deposit taken from the Bug River (in Poland only) are presented. The total y-activity of deposits ranges from 120-650 Bq/kg and the average value is 350 Bq/kg. The elevated activity is chiefly due to the presence of natural radionuclides. The main artificial radionuclides are Cs-137 and Cs-134, whose contribution to the total activity ranges from 0.2 to 6%. The activity of water samples is low, namely 1.7-3.5 Bq/kg and is due to the presence of natural radionuclides. The heterogeneity of the distribution of natural and artificial radionuclides in the studied samples reveals the effect of economical and industrial activities on contamination of the Bug.
The inflorescences of yellow everlasting collected from twenty-two natural sites in the middle part of the Bug river valley were compared as to the contents and composition of flavonoids and phenolic acids. The total contents of flavonoids and phenolic acids ranged from 0.15% to 0.70%, and from 0.45% to 1.52%, respectively. As a result of HPLC analysis eight flavonoid compounds were identified, with isosalipurposide as a dominant constitu­ent. Its content ranged from 2.6 to 13.9 g/100g. The contents of chlorogenic and ferulic acids were also determined.
Studies were carrying out in two shallow (mean depth ≈ 0.3 m) and small (area 2.7–8.2 ha) river lakes, which were flooded by water of River Bug (Eastern Poland) once a year (in spring). The species composition, biomass of phytoplankton and concentration of chlorophyll awere studied. Samples were taken in June (after flooding) and in August (after three months of isolation from river water). About 150 species of phytoplankton were determined. After the flood period phytoplankton biomass was dominated by nannoplankton belonging to Cryptophyceae and Chrysophyceae (strategy-r) and in the stabilization period by microplanktonic green and blue–green algae (strategy-K). The higher biomass and concentration of chlorophyll a values were noted in August than in June. The differentiation of phytoplankton was also stated between near-by stations in both lakes.
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