Serbian Danube Research Articles

Sixth-century Byzantine glass from Limes Fortifications on Serbian Danube

Sixth-century Byzantine glass from Limes Fortifications on Serbian Danube

TOWARDS UAV ASSISTED MONITORING OF AQUATIC VEGETATION WITHIN LARGE RIVERS – THE MIDDLE DANUBE (SERBIA)

UAV technologies provide a time- and cost-efficient framework for a variety of environmental monitoring domains. It also increases data resolution and provides new insights into observed objects and phenomena, especially within the difficult-to-access and complex for monitoring aquatic habitats. The objective of this study was to develop UAV-based acquisition and GIS-based image processing guidelines for aquatic macrophyte detection and monitoring in large temperate rivers. According to the European standard CEN EN -14184:2014, the assessment of aquatic macrophytes should be performed using the transect approach. Large rivers, such as the Danube, represent an exception and should be evaluated using 1km transects. Therefore, seven transects of the Middle Danube in Serbia were simultaneously surveyed using traditional field methods and novel UAV technology. UAV images were acquired using RGB and multispectral cameras carried by a fixed-wing drone. The images were processed and orthomosaics were classified using Object Based Image Analysis (OBIA), to create digital GIS maps of the river transects. During the traditional monitoring approach, the relative abundance of 22 macrophyte species was recorded along the transects. Using the UAV technology and OBIA approach eight macrophyte classes were distinguished based on dominant macrophyte taxa or plant life form traits. Aquatic macrophytes were 'almost perfectly' distinguished from the orthomosaics, achieving a high classification accuracy of 96 % / 88 % / 0.84 for RGB and 94 % / 97 % / 0.95 Producers /Users accuracy/Kappa index for the multispectral approach. Individual macrophyte classes accuracy varied between 0.5 and 1 Kappa and were generally higher for the multispectral imagery approach. Although the resolution of the taxonomic data is lower, UAV monitoring provided the necessary spatial context of macrophytes distribution and absolute area occupied by macrophytes. It also provided information on the diversity and distribution of habitats along the river. Therefore, the UAV-assisted monitoring approach described in this study can be effectively integrated into macrophyte monitoring during large river expeditions such as the JDS.

On the Geochemistry of the Danube River Sediments (Serbian Sector).

To determine the nature and origin of the unconsolidated bottom sediments, as well as to demonstrate and quantify the presence of Presumably Contaminating Elements (PCE) in the Serbian Danube River, as a novelty, the mass fractions on nine major elements as oxides—SiO2, TiO2, Al2O3, FeO, MnO, MgO, CaO, Na2O, and K2O, as well as Sc, V, Cr, Co, Ni, Cu, Zn, As, Rb, Sr, Zr, Sb, Cs, Ba, La, Hf, Ta, W, Th, and U were determined by Instrumental Neutron Activation Analysis (INAA) in 13 sediment samples collected between Belgrade and Iron Gate 2 dam. INAA was chosen for its ability to perform elemental analysis without any preliminary sample treatment that could introduce systematic errors. The distribution of major elements was relatively uniform, with the sampling locations having less influence. Concerning the trace elements, excepting the PCE Cr, Ni, Cu, Zn, As, and Sb, their distributions presented the same remarkable similarity to the Upper Continental Crust (UCC), North American Shale Composite (NASC), Average Bottom Load (ABL), and Average Dobrogea Loess (AVL), and were in good concordance with the location of the Serbian Danube River in the Pannonian Plain. In the case of considered PCE, both Enrichment Factor and Pollution Load Index showed values higher than the pollution threshold, which pointed towards a significant anthropogenic contamination, and rising concern to what extent the water quality and biota could be affected.

New Late Bronze Age hoard from Srebrenik: a preliminary report

Late Bronze Age hoard from Srebrenik it turned up by chance in May 2016. It was discovered in shallow pit on the slope of the hill facing down towards small stream in the village Rapatnice near Srebrenik (Tuzla Canton). The Srebrenik hoard is the largest hoard of bronze metal work yet found. It consists of over 150 pieces divided into 5 groups: weapons, tools, ornaments, bronze sheets and raw materials (ingots), which defined the hoard to be of large quantity and mixed composition. In those aspects, it represents the application of a classical pattern of hoard finds from the wider Pannonian-Carpathian and Eastern Alpine region. According to the typological analysis and its chronological attributions artifacts from hoard show great similarity with findings from nearby hoards, as that from Boljanić dated to the IInd phase of the Urnfield period hoards of Bosnia and Herzegovina, culturally associated with Late Bronze Age Barice-Gređani group. In cultural and technological aspects, it is interpreted in closer association with characteristic pattern of manifestation of hoards over a wide area of south-western Pannonia basin with Slavonia and Serbian Danube region, i.e. with the hoards of the IInd phase of the Continental Croatia – Veliko Nabrđe and with the IInd phase of the Urnfield hoards of Serbian territory. Consequently, the Srebernik hoard is well synchronized with the Ha A1 phase i.e. with the late 13th first half of the 12th century B.C. of the corrected Central European periodization.

Mass appearance of the Ponto-Caspian invaderPontogammarus robustoidesin the River Tisza catchment: bypass in the southern invasion corridor?

The river Danube is the backbone of the ‘southern invasion corridor’, one of the most important passages for the spread of Ponto-Caspian invaders in Europe. However, not all of these species used the passive or active upstream movement in the main channel to reach the upper sections and tributaries, some found detours. Mass occurrences of the Ponto-Caspian peracarid,Pontogammarus robustoides(Sars, 1894) were recorded at 17 sites along the entire Hungarian section of the River Maros, for the first time in the River Tisza catchment and also in Hungary. Those populations are found ca. 707 km upstream from the closest known and confirmed locality in the lower Danube section. We confirmed their identity by DNA barcoding and showed that all individuals fit in with the lower Danube population, thus identifying the source of this introduction. The most likely vector allowing the jump dispersal of the species is fish stocking in the Romanian section of the River Maros, which − combined with downstream drift to the Serbian Danube section and the relatively busy ship traffic between Belgrade and Vienna − might provide the opportunity to bypass the dispersal barrier represented by the unregulated Middle Danube and open the way towards Western Europe.

Possibility of the Application of Danube, Sava and Morava River Area Shallow Aquifer Groundwater (Serbia) in the Irrigation Purposes

This paper presents the results of the groundwater quality assessment, on the Serbian Danube, Sava and Morava River water area, for irrigation purposes. The analysis was done at 54 locations on the Danube, Sava and Morava River water area (Republic of Serbia). The approach to assess the groundwater quality indicators is based on the sustainable water exploitation and the protection of health and environment. This paper presents an overview of the chemical parameters of water samples from the groundwater sources of the Danube, Sava and Morava River water area, i.e. its shallow aquifer. Indicators on the basis of which the assessment of the possibility of water application for irrigation purposes was done are: electroconductivity, concentration of sodium ions, sodium absorption ratio, residual sodium carbonate, magnesium hazard and permeability index. Based on the presented indicators, the quality of the shallow aquifer groundwater on the Danube, Sava and Morava River water area for the irrigation purposes can be mostly assessed as satisfactory.

Use of Cultural Heritage for Place Branding in Educational Projects: The Case of Smederevo and Golubac Fortresses on the Danube

Medieval fortresses represent an important tangible heritage of a nation’s culture and a valuable development asset for a particular destination on which its place-branding strategy for tourism could be built upon. Traditionally in Serbia, heritage protection and conservation have been mainly concentrated on the tangible aspects of cultural sites and monuments. Nevertheless, with the advent of urban heritage integration in the local sustainable development processes and place-branding strategies, a greater appreciation of the spirit of the place and its intangible components, as well as the need to adapt it to local contexts with more participatory forms of heritage planning, have started to emerge. A wide range of stakeholders brought the involvement and participation of both the local government and community members, including residents, as an indispensable element of the protection actions and broader urban development policies. The paper aims to validate the correlation between both intangible and tangible cultural heritage and its contemporary use for place branding and tourism development. In doing so, we have employed the case study method on the two fortresses on the Danube in Serbia to show the ways in which local stakeholders have mobilized their forces in cooperation with the university to use their cultural heritage assets for tourism and more extensive sustainable territorial development. We have found that despite new inclusive forms of governance, which is attracting the attention of planning and heritage practitioners in Serbia, the contemporary approach of integrative protection and the intangible aspects of cultural heritage are still not fully utilized. For this reason, in this study, we consider methods based on environmental aesthetics approaches to cultural heritage that point out the significant inclusion of immaterial intangible cultural heritage in an unbreakable bond with material tangible heritage. The most remarkable result of our research is that while a vast number of stakeholders with local knowledge and sense of the spirit of the place have been involved in the planning process, intangible aspects of the analyzed heritage cases are present in educational projects, and are only partially present if it comes to implementation. This clearly demonstrates that the focus on tangible aspects and spatial interventions of the place branding of cultural heritage is still dominant in Serbia, despite acknowledgment of the economic and social aspects of sustainability in the planning phase in educational projects.

Dynamic of Brassicogethes aeneus (F.) (Coleoptera, Nitidulidae) populations in Serbia’s downriver Danube section and their susceptibility to insecticides

This paper presents data on the dynamic of B. aeneus populations in winter oilseed rape in the downriver section of the Danube in Serbia, which were acquired by yellow water traps and a beating method. Their susceptibility to several insecticides of different classes (organophosphates, pyrethroids and neonicotinoids) (adult vial test and dipping test) was tested over two seasons (2009 and 2010). B. aeneus populations developing under the agroecological conditions that exist in Serbia were monitored to detect the moment of OSR infestation during its sensitive growth stages. Adults were counted, and the data revealed that they infest winter OSR crops during the stem elongation growth stage (BBCH 30-31), reaching a population peak at the green-yellow bud stage (BBCH 57-59), and exceeding the economic threshold, while the populations decreased substantially during the subsequent stage (BBCH 61-69). Laboratory test results did not confirm any changes in B. aeneus susceptibility/resistance to pyrethroid, organophosphate and neonicotinoid insecticides. Migration of B. aeneus populations was monitored as a way of developing predictive models for estimation of infestation severity and the timing of pest outbreaks under agroecological conditions existing in Serbia. As resistance to pyrethroids has been confirmed in B. aeneus populations in many European countries, their susceptibility will be further monitored.

Combined effects of physical environmental conditions and anthropogenic alterations are associated with macrophyte habitat fragmentation in rivers - Study of the Danube in Serbia

We hypothesize that the physical features of river habitats and anthropogenic hydromorphological alterations influence macrophyte communities and lead to habitat fragmentation. Sampling included 1081 contiguous survey units positioned in the main channel and side arms along 588km of the Danube River, along its middle course. To identify habitat fragments, Multivariate Regression Tree analysis (MRT) was applied on macrophyte and environmental data. Indicator species analyses were combined with MRT. To identify habitat fragments on a scale larger than final MRT groups, we set thresholds for an MRT complexity parameter. We identified 20 fine, 7 medium, and 3 large scale habitat fragments. Damming was the main fragmentation agent. Macrophyte communities show continuous variation at all scales of habitat fragmentation. High species diversity indicates major anthropogenic alteration of the river's hydrology and decline of the natural riparian zone. Future studies of the macrophyte communities, and their habitat fragmentation must include more factors (e.g. nutrient status, physicochemical quality of the water, etc.), as well as assessment of the importance of tributaries.

Assessing Accessibility and Transport Infrastructure Inequities in Administrative Units in Serbia’s Danube Corridor Based on Multi-Criteria Analysis and Gis Mapping Tools

The Danube Regions, especially the sub-national units of governance, must be ready to play an active role in spatial development policies. A precondition for this is good accessibility and the coordinated development of all transport systems in the Danube corridor. The main contribution of this paper is to provide a multi-criteria model for potential decision making related to the evaluation of transportation accessibility in Serbia’s Danube Corridor. Geographic Information Systems (GIS), based on maps, indicate the existing counties’ transport infrastructures inequities (between well-connected and isolated counties in terms of accessibility to central places). Through the research, relevant indicators have been identifi ed. This provides an outline of transportation perspectives regarding the development achieved and also fosters the increase of transportation accessibility in some peripheral Serbian Danube administrative units – counties (Nomenclature of Territorial Units for Statistics level 3 – NUTS 3).

Risk of thermal pollution of the Danube passing through Serbia due to thermal power plants

A thermal power plant (TPP) uses large amounts of fresh water, mostly for cooling purposes. Among different types of cooling systems, once-through cooling is the most water-intensive and has the greatest environmental impacts. From the view-point of the steam cycle efficiency, this type of cooling still provides the most efficient electricity production, and therefore is widely used. Water is withdrawn from nearby water bodies, absorbs heat from the steam in a condenser, and then discharged back to its original source at higher temperatures causing severe environmental impacts, including fish killing, disturbing ecosystems, and heating-up natural water bodies. The total installed capacity of almost 1100 MW on the right bank of the Danube in Serbia threatens the ecosystem of this large international river due to thermal pollution. This problem will be even more pronounced in the near future, due to an inevitable increase in production capacity for new 350 MW, currently under construction. Herein, analysis of the legal framework for the protection of water from thermal pollution as well as analysis of the actual situation on the site of the TPP ?Kostolac? in Serbia are presented. Based on meteorological and hydrological parameters, configuration and operation parameters of the plant, the numerical simulation of the condenser was carried on. The temperature of the water leaving condenser and amount of heat discharged back to the river are obtained. According to those results, the analysis of the existing thermal pollution of the Danube River in the flow through Serbia is given by numerical simulation using software ANSYS CFX. Analysis of thermal discharge into the Danube for the five-year period has been carried out. The cooling water effluent causes a temperature increase in the area of the right bank of the Danube, and this thermal disturbance extends along the right river bank for kilometers. Note that the flow rate of the Danube is currently large enough to compensate this thermal disturbance, but for a smaller river and/or larger electricity production capacities, this influence would have even more significant consequences on the ecosystem, making those results even more useful for further analysis.

Indicators of tourism development of the Serbian Danube region

Protected natural area in the Danube region covers 107,200 hectares and includes two national parks, two nature parks, one place of outstanding natural beauty, five special natural reserves, twenty-five nature monuments, and two sites of international significance included in the Ramsar list. However, only 140 immovable and 374 movable cultural objects are officially registered. There are 31 cultural objects of exceptional importance and national significance and 89 objects of great importance and regional significance. The objects with this status are protected by the state. Two sites are on the preliminary UNESCO World Heritage list. This paper discusses the potential of tourism industry in the Serbian Danube Region and the prospects of its further development. We outline the current state of tourism industry and describe the geographical location of the region, its natural and anthropogenic resources, and accommodation capacities. We analyse such data as the number of tourists and the number of overnight stays by municipalities in 2016, and the average length of stay. The indicators used are the functionality coefficient, the capacity utilization and the intensity of functionality. The conclusion is drawn that the tourism potential of the Serbian Danube Region is not fully realized and that its development should be at a much higher level, given the increasingly important role of the region as a major tourist destination in Serbia.

The relationship between habitat factors and aquatic macrophyte assemblages in the Danube river in Serbia

Our objectives were to offer insight into the characteristics of the physical environment in the River Danube in Serbia; and to show the relationship between selected environmental factors and the composition and abundance of macrophyte species. The macrophyte survey method followed the European Standard EN 14184, applying Kohler?s five-level descriptive scale. Principal component analysis was carried out to examine the variation in aquatic vegetation, and to analyze the effect of environmental variables on the aquatic vegetation, redundancy analysis was used. To build a simpler model with fewer explanatory variables, yet sufficiently explaining species variability, forward selection of environmental variables was done. Our results confirmed that physical environmental factors significantly influence the establishment and structure of macrophyte vegetation, with the level of hydrological connectivity to the main river channel being the most important, followed by the transparency of the water column, sediment texture and water-flow velocity. In order to inspect the individual relation between best-fitted plant species and each of selected environmental variables, Spearman?s rank correlation coefficients were calculated. We have distinguished plant species with preferences to specific combinations of analyzed factors. Our results provide a background for future, more specific studies on the macrophyte/habitat relationship.

Landslides in hard soils and weak rocks

Landslides in hard soils and weak rocks

Application of multi-criteria analysis and GIS in ecotourism development (Case study: Serbian Danube region)

Ecotourism can be defined as responsible travel to natural areas that conserves the environment and cultural heritage and improves the well-being of local people. Sustainable planning and management of ecotourism development are important and necessary for increasing positive and decreasing negative effects on the complex environment. This paper analyses the suitability of selected protected natural areas in the Serbian Danube region for the purposes of ecotourism development. The multi-criteria analysis includes several natural and socio-economic factors and criteria which influence ecotourism development. The integration of Geographic Information System (GIS) and Analytic Hierarchy Process (AHP) greatly facilitates the decision-making process in the ecotourism destination planning. A suitability map of the analysed protected natural areas for ecotourism development as one of the sustainable tourism types is highlighted as a result of this paper. Such analysis assists in the objective promotion of ecotourism destinations and thus contributes to the improvement of Serbian tourism development.

The Serbian Danube region as tourist destination

The aim of this paper is to show the advantages and disadvantages of the Serbian Danube Region as a tourist destination. Tasks to be completed in order to achieve the set aim include: determining the position of the Serbian Danube Region from the perspective of transportation geography, identifying its natural and anthropogenic tourism assets, its tourism infrastructure, as well as the types of tourism that can develop there based on the above. The methods used in this paper comprise: the cartographic method; a statistical method used for determining monthly and annual mean values of the Danube water level, water temperature and climatic elements for the period 1991-2010, the number of tourists and overnights in the Danube Region in 2012, as well as the number of accommodation facilities and their comparison for the years 2010 and 2012; the analytic and synthetic method; the fieldwork method combined with the photographic method, etc. The only conclusion that can be drawn is that the potentials of the Serbian Danube Region for tourism development have not been sufficiently valorised or realised except in Belgrade and Novi Sad. Therefore, taking action and measures in connection with sustainable development of tourism would favour economic development outside major cities, advance the spatial distribution of population and improve the overall social situation.

Indicators of unsustainable fishery in the Middle Danube

AbstractFishery in the Danube River basin has been characterised over the past century by increasing fishing levels, illegal fishing practices and poor regulations. However, there is a remarkable lack of available information on the actual status of fish stocks, as well as on the trends and sustainability of fisheries, which poses a problem for the development of adequate policy and management measures. In this study, we assessed the trends in the commercial fishery in the Middle Danube in Serbia during 1969–1989 and 2006–2010 by evaluating the temporal changes in life history‐related indicators that might point out unsustainable fishing pressures. Moreover, we present the approach of using the catch‐weighted mean egg‐per‐recruit (EPR) index as a proxy for the overall resilience of fish stocks to fishing. Results indicated a marked shift towards smaller fish that mature earlier and have a shorter lifespan. Landings also shifted towards species at lower trophic levels, with a mean trophic level decline at a rate of approximately 0.16 per decade. Results indicated likely presence of the ‘fishing through the food web’ phenomenon. At the same time, catch‐weighted community mean of the 20% EPR threshold ratio (EPR20%) increased by 4.2%, indicating the increase of the overall resilience to fishing of the exploited species. Obtained results indicated the importance of using such metrics for the assessments of trends in fishery. The approach and results presented here could be of interest for the scientific community and stakeholders involved in fishery management.

Analysis of solid waste from ships and modeling of its generation on the river Danube in Serbia

This study focuses on the issues related to the waste management in river ports in general and, particularly, in ports on the river Danube's flow through Serbia. The ports of Apatin, Bezdan, Backa Palanka, Novi Sad, Belgrade, Smederevo, Veliko Gradiste, Prahovo and Kladovo were analyzed. The input data (number of watercrafts, passengers and crew members) were obtained from harbor authorities for the period 2005-2009. The quantities of solid waste generated on both cruise and cargo ships are considered in this article. As there is no strategy for waste treatment in the ports in Serbia, these data are extremely valuable for further design of equipment for waste treatment and collection. Trends in data were analyzed and regression models were used to predict the waste quantities in each port in next 3 years. The obtained trends could be utilized as the basis for the calculation of the equipment capacities for waste selection, collection, storage and treatment. The results presented in this study establish the need for an organized management system for this type of waste, as well as suggest where the terminals for collection, storage and treatment of solid waste from ships should be located.

Qualitative study of Mollusca communities in the Serbian Danube stretch (river km 1260–863.4)

First detailed limnological study was performed from April 2003 to June 2008 in a 396.6 km long section of the Serbian Danube (divided in three parts; from 1260 r-km to 863.4 r-km) to examine community composition and spatial distribution of Mollusca with special attention to the expansion of Ponto-Caspian species, propagation of invasive and introduced species and occurrence of endemic species. Mollusca samples were collected at 15 sites in April, June, September and November. We investigated the spatial distributions and calculated the faunistic similarity of localities with respect to the community composition using the Sorensen Quotient of Similarity. Site variation in analyzed qualitative traits was examined using correspondence analysis. Additionally, the obtained Complete Linkage City-block (Manhattan) distances among sites/parts were subjected to UPGMA (unweighted pair-group method using arithmetic averages) cluster analysis. The class Gastropoda was represented by 18 species from two subclasses (Prosobranchia — six families and Pulmonata — three families).The class Bivalvia was represented by 15 species from four families of order Eulamellibranchiata. Mollusca were represented by 33 species belonging to 17 genera and 13 families. Out of five recorded Ponto-Caspian species in the studied Danube stretch, Lithoglyphus naticoides (Pfeiffer, 1828) and Dreissena polymorpha (Pallas, 1771) are assumed to be invasive species with the highest occurrence frequency (F = 1, each). Four new species in invertebrate fauna for the Danube, denoted as the introduced species — Neozoa, were identified: Theodoxus fluviatilis (L., 1758), Corbicula fluminalis (Muller, 1774), C. fluminea (Muller, 1774), and Sinanodonta woodiana (Lea, 1834). The only endemic species of Gastropoda found in the Danube was Viviparus acerosus Bourguignat, 1862.

Genetic structure and phylogeography of a European flagship species, the white‐tailed sea eagle Haliaeetus albicilla

We analysed 120 white‐tailed sea eagles Haliaeetus albicilla from eastern (Poland and Estonia) and southeastern (Serbian Danube population) Europe for genetic variability and structuring at the mitochondrial control region and seven nuclear microsatellite loci. We combined this new dataset with sequence and genotype data from previous analyses covering Greenland and Eurasia (total sample sizes of 420 and 186 individuals for mtDNA and microsatellites, respectively) to address the following questions: 1) does the large eastern population in Europe add significantly to the species‘ overall genetic diversity? 2) Do the new sequence data match the clinal distribution pattern (west to east) of the two major mtDNA lineages? 3) Does the preliminary hypothesis of two nuclear genetic clusters recently found in this species hold for the whole of Europe, and do these clusters show a geographic pattern? Our results confirmed Europe as a stronghold of genetic diversity in white‐tailed sea eagles, and the east of the continent contributed disproportionately to this, the reason being the admixture of eagles with different genetic background. As hypothesised, both mitochondrial lineages were recovered also in eastern Europe, but the globally more eastern lineage was dominant. The presence of two microsatellite clusters was also confirmed, and these groups, too, show a non‐random geographic distribution, with, except for Poland, a high proportion of ‘eastern‐type’ eagles in the populations of east–central and eastern Europe.