Content of the potentially harmful elements in soil around the major coal-fired power plant in Serbia: relation to soil characteristics,evaluation of spatial distribution and source apportionment

The concentrations and spatial distribution of nine potentially harmful elements (PHEs), namely Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, and their relation to soil properties were investigated in thirty soil profiles (0–50 cm depth) sampled around the largest Serbian coal-fired power plant (CFPP) “Nikola Tesla A.” Soil properties were determined following standard procedures, and total contents of PHEs were analyzed by atomic absorption spectrometer. Concentrations of Cd, Co, Fe, Mn, Pb and Zn were the highest in soil profiles sampled 1 km away from the CFPP, concentrations of Ni and Cu gradually increased up to 4 km, and the highest Cr concentrations were measured in samples taken 6 km away from the CFPP. The highest concentration of PHEs analyzed, except Mn, corresponded with predominant wind directions. Depth did not show significant impact on distribution of any PHEs investigated. Among soil properties, the total organic carbon showed the closest relationship with the PHEs. Data were processed by a principal component analysis which enabled distinguishing anthropogenic from natural influences on soil properties and PHE contents. Although the impact of CFPP operations is obvious, assets of principal component analysis did not allow clear distinction of CFPP’s contribution from parent material in enrichment of PHE contents in the soil in the study area.     

Behaviour of metals and nutrients in soils and groundwater of a karst polje

The Croatian south part of the country is mainly composed of strongly krastified carbonate rocks. Also in this south part of Croatia is lacking of large depressions and poljes with thick covers. Some karst poljes and depressions may have thick covers, like for example the Vransko polje. The Vransko polje is characterised by an intensive agricultural activity. At the centre of the polje is located a karst spring (Turanjsko jezero), which is used for the water supply of the town Biograd and its surroundings. Total metals, nutrients (nitrate, ammonia, phosphate), organic matter content and cation exchange capacity (CEC) were measured in soil samples collected from the polje. Metals and nutrients were also measured in the water samples of channel Kotarka (which is passing through the area) and three springs (Turanjsko jezero, Kakma and Tinj). Measured total concentrations of metals of soil samples were treated by R-cluster multivariate statistical analysis. The result of statistical analysis showed grouping of metals with similar behaviour. Content of metals and nutrients were low in the spring samples but high in the water sample of the channel Kotarka, because the channel drains the water from the surroundings. Although agricultural activity in the Vransko polje is high, there is no high anthropogenic influence on groundwater and soil. They are both of good quality.     

Seismic response analysis using characteristic ground motion records for risk‐based decision‐making (3R method)

The concept of intensity‐based assessment for risk‐based decision‐making is introduced. It is realized by means of the so‐called 3R method (response analysis, record selection and risk‐based decision‐making), which can be used to check the adequacy of design of a new building or of the strengthening of an existing building by performing conventional pushover analysis and dynamic analysis for only a few ground motions, which are termed characteristic ground motions. Because the objective of the method is not a precise assessment of the seismic risk, a simple decision model for risk acceptability can be introduced. The engineer can decide that the reliability of a no‐collapse requirement is sufficient when collapse is observed in the case of less than half of, for example, seven characteristic ground motions. From the theoretical point of view, it is shown that the accuracy of the method is acceptable if the non‐linear response history analyses are performed at a low percentile of limit‐state intensity, which is also proven by means of several examples of multi‐storey reinforced concrete frame buildings. The 3R method represents a compromise between the exclusive use of either pushover analysis or dynamic analysis and can be easily introduced into building codes provided that its applicability is further investigated (e.g. asymmetric structures and other performance objectives) and that the procedure for the selection of characteristic ground motions is automated and readily available to engineers (www.smartengineering.si).     

Ballast water sampling as a critical component of biological invasions risk management

The human mediated transfer of harmful organisms via shipping, specifically via ballast water transport, leading to the loss of biodiversity, alteration of ecosystems, negative impacts on human health and in some regions economic loss, has raised considerable attention especially in the last decade. Ballast water sampling is very important for biological invasions risk management. The complexity of ballast water sampling is a result of both the variety of organism diversity and behaviour, as well as ship design including availability of ballast water sampling points. Furthermore, ballast water sampling methodology is influenced by the objectives of the sampling study. In the course of research conducted in Slovenia, new sampling equipment for ships' ballast water was developed and tested. In this paper new ballast water sampling methods and equipment together with practical shipboard testing results are presented.     

Marine sampling by scuba diving. 3. Sampling procedures for measurement of mercury concentrations in estuarine waters and seawater

A method for sampling estuarine waters and seawater by scuba diving is described. Samples taken from the Krka River Estuary on the eastern Adriatic coast were analysed for mercury content using cold vapour atomic absorption spectrometry (CVAAS). Mercury levels as low as 1 ng dm⁻³ were determined and these are among the lowest values reported to date. A simple contamination free procedure for the preconditioning of sample containers in the sea was applied. Sampling of water by divers is particularly useful when the intermediate layer in an estuary has to be identified and sampled, as well as for obtaining detailed vertical concentration profiles for mercury and other trace elements.     

Provenance of the HP–HT subducted margin in the Variscan belt (Cabo Ortegal Complex,NW Iberian Massif)

The Variscan Upper Allochthon is a continental‐affinity terrane that recorded a Cambrian–Ediacaran magmatic arc generation, a subsequent transition to a passive margin, and a collision‐related high‐P metamorphism during the Devonian–Carboniferous amalgamation of Pangea. The objective of this article is to decipher which continental margin subducted in the Devonian high‐P–high‐T (HP–HT) event. To do so, a provenance study is presented using combined U–Pb (n = 613) and Lu–Hf (n = 463) isotopic LA–ICP–MS zircon analyses and Sm–Nd whole–rock (n = 5) determinations. These analyses have been performed on five samples of the Banded Gneisses (Cabo Ortegal Complex, NW Iberia), which forms a part of the HP–HT bottom member of the Upper Allochthon. Palaeozoic–Neoproterozoic zircon ages (34.7%) have a maximum abundance at 522–512 Ma, peaks at 575, 561, 545 Ma and minor abundance peaks between 780 and 590 Ma, and show from their Lu–Hf compositions a volcanic arc mixing pattern. This arc was probably related to the Cadomian arc system. The Mesoproterozoic population is scarce and scattered (2.8%), and due to its Lu–Hf pattern, it is proposed that this population is also West Africa Craton derived. The Paleoproterozoic population (39.6%) is concentrated at 2.07 Ga and it is linked to the Eburnean Orogeny, where depleted mantle derived magmas intruded an Archean craton margin. This craton is represented by the Archean population (22.8%), which is grouped at 3.0, 2.68‐2.61 and 2.52‐2.48 Ga, and shows long‐term reworking processes and at least two juvenile magma intrusions. These data show that the Variscan Upper Allochthon has a West African provenance and therefore, it strongly suggests that the NW Iberian allochthonous complexes and their correlative European terranes are also West Africa derived. These results allow us to finally clarify that the first high‐P event, recorded during the eo‐Variscan amalgamation of Pangea, was attained by the subduction of the margin of Gondwana under Laurussia.     

Using Temperature Fluctuation Measurements to Estimate Meteorological Inputs for Modelling Dispersion During Convective Conditions in Urban Areas

We examine the performance of several methods to estimate meteorological inputs for modelling dispersion in urban areas during convective conditions. Sensible heat flux, surface friction velocity and turbulent velocities are estimated from measurements of mean wind speed and the standard deviation of temperature fluctuations at a single level on a tower at two suburban sites and at one urban site in Riverside, California. These estimates are compared with observations made at these sites during a field study conducted in 2007. The sensible heat flux is overestimated in the urban area, while it is underestimated at a suburban site when temperature fluctuations are used in the free convection formulation to estimate heat flux. The bias in heat flux estimates can be reduced through a correction that depends on stability. It turns out that the bias in heat flux estimates has a minor effect on the prediction of surface friction velocity and turbulent velocities. Estimates of sensible heat flux, surface friction velocity and turbulent velocities are sensitive to estimates of aerodynamic roughness length, and we suggest estimating the aerodynamic roughness length through detailed micrometeorological measurements made during a limited field study. An examination of the impact of the uncertainty in estimating surface micrometeorology on concentrations indicates that, at small distances from a surface release, ground-level concentrations computed using estimates of heat flux and surface friction compare well with the those based on observed values: the bias is small and the 95% confidence interval of the ratio of the two concentrations is 1.7. However, at distances much larger than the Obukhov length, this confidence interval is close to 2.3 because errors in both friction velocity and heat flux affect plume spread. Finally, we show that using measurements of temperature fluctuations in estimating heat flux is an improvement on that based on the surface energy balance, even when net radiation measurements are available.     

ASSESSMENT OF MACCORMACK SCHEME IN UNSTEADY SEDIMENT LADEN FLOW COMPUTATION

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Regional Flood Frequency Analysis Based on L-Moment Approach (Case Study Tisza River Basin)

Water Resources - Floods are one of the most common natural hazards and as such, they are causing a great loss of human life as well as great economic damages. Flood frequency analysis (FFA) is...