We investigated the recent evolutionary history of the Danube crested newt, Triturus dobrogicus through reconstructions of: (1) the number and position of refugia at the last glacial maximum, (2) the ...role of major central European rivers in pattern of post‐glacial dispersal, and (3) the present‐day distribution pattern. We analysed sequences of mitochondrial DNA (ND2, 1065 bp) and six microsatellite loci in 363 T. dobrogicus individuals from 58 populations covering the range of the species. Our analyses suggested that T. dobrogicus survived the last glacial maximum in two separate refugia positioned in northwestern Pannonia and in Southern Pannonia from where its range expanded along the Danube and Tisza Rivers. Our findings also confirmed that rivers played an important role in shaping the evolutionary history of amphibian species in Central Europe. We compared the T. dobrogicus range with another lowland amphibian, the fire‐bellied toad Bombina bombina, using species distribution modelling. In line with these models, the isolated mountains inside Pannonia are occupied not by B. bombina, but by its mountain‐dwelling sister‐species B. variegata. However, in contrast to the model, crested newts (including T. dobrogicus) are absent from these mountains. We attribute this biogeographical discrepancy to the positioning of the species’ refugia at the last glacial maximum.
Regional flood frequency analysis (RFFA) is a powerful method for interrogating hydrological series since it combines observational time series from several sites within a region to estimate ...risk-relevant statistical parameters with higher accuracy than from single-site series. Since RFFA extreme value estimates depend on the shape of the selected distribution of the data-generating stochastic process, there is need for a suitable goodness-of-distributional-fit measure in order to optimally utilize given data. Here we present a novel, least-squares-based measure to select the optimal fit from a set of five distributions, namely Generalized Extreme Value (GEV), Generalized Logistic, Gumbel, Log-Normal Type III and Log-Pearson Type III. The fit metric is applied to annual maximum discharge series from six hydrological stations along the Sava River in South-eastern Europe, spanning the years 1961 to 2020. Results reveal that (1) the Sava River basin can be assessed as hydrologically homogeneous and (2) the GEV distribution provides typically the best fit. We offer hydrological-meteorological insights into the differences among the six stations. For the period studied, almost all stations exhibit statistically insignificant trends, which renders the conclusions about flood risk as relevant for hydrological sciences and the design of regional flood protection infrastructure.
The aim of our study is to expand the world-wide knowledge about pollutant transport in sediments of medium-sized meandering rivers and to explain barium distribution in Kupa River (Croatia), which ...showed as an ideal “natural laboratory”. Sampling was performed twice at the same places with the time span of 15 years to see the changes in Ba concentrations after that period. Ba was analyzed using ICP-MS method on clay + silt sediment fraction (< 63 µm). Modelling was performed in R environment. After barite mine ceased operation in 1990, Ba is still entering Kupica and Kupa rivers, as karstic underground still contains large amounts of barite waste. Ba concentrations in Kupa River sediments are still increasing consequently along the whole river length, except in Kupica River and first downstream sample in Kupa River. It seems that in this part of the river course erosion exceeded deposition processes. Also, there is an indication of changing the way of underground Ba transport. Erosion and deposition processes lead to formation of peak of Ba concentrations in the lower course of the Kupa River. The most important conclusion is that the peak was formed under one or two flood episodes, when sediment eroded from the upstream locations and was brought and deposited in the lower course of the river. Our modelling predicts that Ba source will not cease during the next 20 years. Additional sampling of river- and ground-water showed that the correlation between Ba in sediment and river water is statistically significant (0.79,
p
< 0.05). This might be result of Ba dissolution from the sediment and dilution with waters entering from Kupa River tributaries.
In 2014, major floods in Serbia caused enormous damage in Obrenovac Municipality. Apart from numerous businesses, the flood affected the water supply system. The water source “Vić Bare” in the ...village of Zabrežje on the Sava river was inundated and the water distribution network, parts of which were relatively old, sustained further harm. Over the past several decades, insufficient groundwater reserves have been one of the main water supply issues in Obrenovac. Recent investigations identified the reserves and the possibility of ensuring additional amounts of groundwater at the existing source was explored. The largest problem, however, is a high water demand due to inefficient water use and water losses in the distribution network. Given that the said water source relies on bank filtration, the flood was extremely important from a hydrogeological perspective. The paper assesses the data collected during the course of extremely high river stages and water tables and examines source discharge capacities to provide further insight into surface water and groundwater interactions and compare the pre- and post-flood status of a municipal water supply source.
Persistent scatterer interferometry (PSI) is capable of millimetric measurements of ground deformation phenomena occurring at radar signal reflectors (persistent scatterers, PS) that are phase ...coherent over a period of time. However, there are also limitations to PSI; significant phase decorrelation can occur between subsequent interferometric radar (InSAR) acquisitions in vegetated and low-density PS areas. Here, artificial amplitude- and phase-stable radar scatterers may have to be introduced. I2GPS was a Galileo project (02/2010–09/2011) that aimed to develop a novel device consisting of a compact active transponder (CAT) with an integrated global positioning system (GPS) antenna to ensure millimetric co-registration and a coherent cross-reference. The advantages are: (1) all advantages of CATs such as small size, light weight, unobtrusiveness and usability with multiple satellites and tracks; (2) absolute calibration for PSI data; (3) high sampling rate of GPS enables detection of abrupt ground motion in 3D; and (4) vertical components of the local velocity field can be derived from single-track InSAR line-of-sight displacements. A field trial was set to test the approach at a potential landslide site in Potoška planina, Slovenia to evaluate the applicability for operational monitoring of natural hazards. Preliminary results from the trial highlight some of the key considerations for operational deployments in the field. Ground motion measurements also allowed an assessment of landslide hazard at the site and demonstrated the synergies between InSAR and GPS measurements for landslide applications. InSAR and GPS measurements were compared to assess the consistency between the methods from the slope mass movement detection aspect.
Data from approximately 500 boreholes and an additional 40 wells for which there is a plausible range of data, facilitate description of the geometry of the Quaternary aquifer and its characteristics ...respectively, and pretension of the elements of the conceptual hydrogeological model in the Sava River valley. The aquifer heterogeneity is caused by tectonic activity and the depositional environments of the sediments within the valley. In the wider Zagreb area, gravel is the dominant component of the aquifer. Downstream from Zagreb, the aquifer is composed mainly of sand with sporadic intercalations of gravel. An admixture of silt and clay is not uncommon within the sand. The exceptions are alluvial fans that were formed by the right tributaries of the Sava River; gravel with sand is dominant in their lithological composition. The best hydrogeological properties of the aquifer system were registered in the vicinity of the Sava River, so all large pumping sites are located close to the river. The Quaternary aquifer is the main source of the water supply in the Sava River valley.
The hyporheic zone (HZ) is a sensitive ecotone in river ecosystems because of its biodiversity and susceptibility to human activities. Hyporheic fauna are exposed to multiple stressors that affect ...the physiology and metabolism of organisms and ultimately ecosystem functioning and biodiversity. This study aimed to quantify adenine nucleotides in the stygophilous freshwater amphipod Synurella ambulans and to evaluate the potential of adenylate energy charge (AEC) as a physiological biomarker of general stress in the HZ of the Sava River at sites with different intensities of environmental and anthropogenic stress. Field studies were conducted seasonally (in December 2018 and April, July, and October 2019) at two sampling sites, one upstream (1-UP) and the other downstream (2-DOWN) of the discharge from the wastewater treatment plant using the standard piston pump. The amphipod population from site 1-UP had significantly higher AEC values than the population from site 2-DOWN in all seasons except summer. Coordinated changes in AEC values with the ATP/ADP ratio indicated differences in energy status between the two populations. However, no changes in the apparent equilibrium constant of adenylate kinase were observed, except in spring at site 1-UP. Multiple linear regression models showed the strongest associations of AEC with Fe and Zn accumulated in amphipods, followed by environmental factors (conductivity, dissolved O2, and concentrations of nitrites and phosphates in the interstitial water). AEC was shown to be a useful index of environmental stress in S. ambulans because it can directly measure the change in available energy and thus the metabolic stress to which the organism is exposed. Finally, seasonal and spatial variations in AEC values reflected ecological status in the HZ.
In an attempt to evaluate the toxicological condition of the most important river and artificial lakes in Serbia, 52 grab-samples were collected from different locations. Sediment samples were ...analyzed for PCBs (PCB 28, PCB 52, PCB 101, PCB 138, PCB 153, PCB 180, and PCB 194), organochlorine pesticides (α-HCH, β-HCH, γ-HCH, benzene hexachloride, heptachlor, heptachlor epoxide, aldrin, endrin, dieldrin, DDE, p,p′-DDD, p,p′-DDT, o,p′-DDT, and methoxychlor), triazine herbicides (atrazine, simazine, and propazine) and PAHs (fluoranthene, benzobfluoranthene, benzokfluoranthene, benzoapyrene, benzog,h,iperylene, indeno1,2,3,-c,dpyrene). The principal objective was to establish the considered basins. The content of triazine herbicides were below the detection limits (<MDL) in all sediment samples. Total contents of PCBs ranged from <MDL to 57.0μgkg−1 and PAHs from <MDL to 728μgkg−1. The concentrations of organochlorine pesticides ranged from <MDL to 113μgkg−1. The most abundant organochlorine pesticide was the DDT and its degradation products. Obtained result shows ongoing recent inputs of DDTs to the rivers. The evaluations suggest that environmental persistent toxic substances levels are generally relatively low, although organochlorine pesticides may be an issue in some areas of the basin (Tisa, Sava, and Topčiderska river).
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•The persistent organic pollutants (POPs) in rivers and man-made lakes sediments of Serbia were studied.•The investigated sediments are mainly influenced by pesticides and PAHs.•All investigated sediments accumulated p,p′-DDT.
Purpose
River ecosystems are under pressure from several different stressors. Among these, inorganic pollutants contribute to multiple stressor situations and the overall degradation of the ...ecological status of the aquatic environments. The main sources of pollution include different industrial activities, untreated effluents from municipal waste waters and intensive agriculture. In the present study, water, suspended particulate matter (SPM) and sediments of the Sava River were studied in order to assess the pollution status of this river system.
Materials and methods
Sampling was performed during the first sampling campaign of the EU 7th FW funded GLOBAQUA project in September 2014, at 18 selected sampling sites along the Sava River. In 2014, floods predominated from spring to fall. Water samples were collected to determine the total element concentrations, the dissolved (0.45 μm) fraction and element concentrations in SPM. In order to assure comparative results with other river basins, the fraction below 63 μm was analysed in sediments. The extent of pollution was estimated by determination of the total element concentrations and by the identification of the most hazardous highly mobile element fractions (extraction 0.11 mol L
−1
acetic acid) and anthropogenic inputs of elements to sediments (normalization to aluminium (Al) concentration). Concentrations of selected elements were determined by inductively coupled plasma mass spectrometry (ICP-MS).
Results and discussion
Since during sampling campaign the water level was extremely high, water samples contained high amounts of SPM (in general between 80 and 100 mg L
−1
). The data of chemical analysis revealed that concentrations of elements in water, SPM and sediments in general increase along the Sava River from its origin to the confluence with the Danube River. Elevated concentrations of chromium (Cr) and nickel (Ni) in SPM and sediments were observed at industrially exposed sites. Concentrations of Cr and Ni in sediments were up to 320 and 250 mg kg
−1
, respectively. Nevertheless, these elements were present in sparingly soluble forms and hence did not represent an environmental threat. Phosphorus (P) was found in elevated concentrations (up to 1500 mg kg
−1
) at regions with intensive agricultural activities and cities with dense population.
Conclusions
With respect to element concentrations, the pollution of the Sava River is similar to other moderately polluted European rivers. The data from the present study are beneficial for the water management authorities and can contribute to sustainable utilization, management and protection of the Sava River water resources.
The Sava River and its tributaries in Slovenia represent waters strongly influenced by chemical weathering of limestone and dolomite. The carbon isotopic compositions of dissolved inorganic carbon ...(DIC) and suspended organic carbon (POC) fractions as well as major solute concentrations yielded insights into the origin and fluxes of carbon in the upper Sava River system. The major solute composition was dominated by carbonic acid dissolution of calcite and dolomite. Waters were generally supersaturated with respect to calcite, and dissolved CO₂ was about fivefold supersaturated relative to the atmosphere. The δ¹³C of DIC ranged from -13.5 to -3.3per thousand. Mass balances for riverine inorganic carbon suggest that carbonate dissolution contributes up to 26%, degradation of organic matter ~17% and exchange with atmospheric CO₂ up to 5%. The concentration and stable isotope diffusion models indicated that atmospheric exchange of CO₂ predominates in streams draining impermeable shales and clays while in the carbonate-dominated watersheds dissolution of the Mesozoic carbonates predominates.
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