Hydrogeological and hydrodynamic characteristics of groundwater sources for the public water supply of Bečej (Northern Serbia)

The existing groundwater source for the public water supply of Bečej City in Serbia is tapping groundwater from three water-bearing horizons over 15 wells with a summary capacity over 100 l/s. It is one of the characteristics of sources that several water-bearing layers are most frequently tapped simultaneously by wells. Two layers are tapped simultaneously by 12 wells; all three layers are tapped by ten wells, while one water-bearing layer is tapped by only three wells. The groundwater table at the source was recorded for a period of 30 years. In the conducted hydrodynamic analysis of the groundwater regime, it was concluded that in the mentioned period, a relatively low fall of the water table occurred, far lower than the previously predicted values. The results of a simulation of the exploitation regime of both the town and surrounding sources are presented in this paper for a period of more than two and a half years and the results of the identification of the basic hydrogeological parameters of the tapped water-bearing layers are presented in this paper. In addition, a balance for each element in the water-bearing layers exploited as sources of tapped water for the town are presented

Karst aquifer average catchment area assessment through monthly water balance equation with limited meteorological data set: Application to Grza spring in Eastern Serbia

In the absence of detailed exploration of karstic catchments, the calculation of available reserves and elements of the water balance equation frequently reflect the topographic size of the catchment area, and not the actual, active (underground) size. The two differ largely where karst is concerned. The paper deals with the problem of average catchment area size estimation in the situation when meteorological data are limited to precipitation and temperature, but discharge records are available for long period. Proposed methodology was applied to, calibrated, and validated on 15 karst springs in Serbia. Results obtained with the model differ up to 20% from hydrogeological exploration results. One of investigated springs is Grza karst spring, which belongs to the karstic formation of Kučaj and Beljanica (the Carpatho-Balkanide Arch of Eastern Serbia). In this paper, we used the Grza Spring to show model application and necessary improvements to progress from graphoanalytical to analytical model. The average catchment area is linked to the model parameter that reduces potential to real evapotranspiration on monthly bases. The model potential lies in the possibility to determine not only catchment area, but real evapotranspiration and dynamic volume of the porous - karst groundwater storage as well

Assessment of environmental radioactivity and health hazard at Stara Planina region

The aim of the study was to evaluate the potential risks of radiation near abandoned uranium mines, tailing dumps, or uranium deposits on Mountain Stara Planina, Serbia. For risk assessment several parameters were determined: Radium equivalent activity, Raeq, external hazard index, Hex, gamma radiation absorbed dose rate, D, annual effective dose on background outdoor gamma exposure, AEDoutdoor, and excess lifetime cancer risk, ELCR. Obtained results showed that all the samples, except one, have the Raeq value up to two times higher than the reference limit. The Raeq of the sample from the Mezdreja mine tailings was increased by almost eight times. The value of Hex followed the same pattern as Raeq. All the investigated localities have increased D values, while all the samples have shown the moderately low AEDoutdoor, except Mezdreja mine tailings that have 5.5-2.8 times higher dose relative to the world's average. ELCR at the Mezdreja mine tailings is 4.58 times higher than the world's average of 1.45-10-3. In the context of human activity in the area of Stara Planina such as different kinds of tourism, livestock breeding, dairy products, and herbal manufacturing, etc. there is a need for detailed analysis in order to evaluate potential human exposure and health impacts

SPATIAL-TEMPORAL VARIABILITY OF AIR TEMPERATURES IN SERBIA IN THE PERIOD 1961–2010

The aim of this paper is to examine the spatial and temporal variability of the average monthly, seasonal and annual air temperatures in Serbia. Therefore, data from 64 climatologic stations were analyzed in the period from 1961 to 2010. Based on the data, on the position of the stations (their latitude, longitude, altitude), and the characteristics of the terrain in their vicinity (inclination and terrain exposure in a radius of 10 km around the station), a regression model was constructed based on which air temperatures are interpolated for the territory of Serbia. The rootmean-square error (RMSE) of the regression model ranged from 0.2 ºC in January, February and November to 1.1 ºC in August. Spatial distribution of air temperatures is shown (maps of mean monthly, mean seasonal and mean annual air temperatures are made), and the Sen's procedure was used to calculate trends of air temperatures (maps of average monthly, mean seasonal and mean annual trends of air temperatures). The Mann-Kendall test was used to test the significance of air temperature trends. Apart from the southeast, the whole territory of Serbia has practically experienced a statistically significant rise in the average annual air temperature, with the highest increase in the summer and winter months

Investigation of accessory elements of representative petrologic radioactivity carriers at Stara Planina, Serbia

The present study deals with the abundance of the most common accessory elements of radioactivity carriers on the Stara Planina mountain at four defined locations. All investigated locations have increased radioactivity, greater than 200 cps, up to 1250 cps. In all examined samples the following elements were detected and their concentrations were determined: Zr, Rb, W, Mo, Sn, Zn, Cu, As, Sb, Ba, Ni, Cr, V, and Ti. The analysis showed that depending on the sample, elevated concentrations of all detected elements except titanium were found. As all localities containing the listed detected elements are located near watercourses, all the present elements, and in particular, those with elevated concentrations can be relatively easily transferred to the environment by water action. Likewise, there is the possibility of eolic erosion from the investigated deposits and tailing dams whereby these chemical elements and/or radionuclides would be distributed to areas away from the primary sources of natural radioactivity. These have a high risk of spreading and therefore have harmful or radioecological effects on the environment. The study indicated a need for adequate monitoring, and risk assessment of the examined locations, which could prevent the distribution of these elements further into the environment

The Content of Toxic Metals in Agricultural Produce near a Coal Mine: Case Study KCB in Lazarevac, Serbia

The monitoring and analysis of concentrations of toxic metals (lead and cadmium) in soils and crops indicate that farmland in Serbia is generally not polluted, and the quality of soils is naturally good. Such soils are therefore suitable for organic farming. All noted instances of contamination by toxic metals are of a local nature only, and the result of fertilizers and pesticides, municipal waste, exhaust gases, nearby production facilities, smelting plants, mines, tailings ponds, etc. Locations of this type need to be monitored regularly, and the status of the soil and crops assessed. The results presented in this paper place special emphasis on lead and cadmium. In this regard, the sampling of 67 plant foodstuffs that are being grown in Baroševac village, located in the immediate vicinity of the Kolubara coal mine, was carried out. Fruit samples represented 14.9% and vegetable samples 85.1% of the total sample. The heavy metal content (lead/cadmium) in seven samples was above the limits prescribed by the Regulations. Overall exposure of the adult population of Baroševac, calculated on the basis of all samples (67 in total), was 0.89 µg lead per kg of body weight per week, representing only 3.5% provisional tolerable weekly intake (PTWI), and 0.46 cadmium per kg of body weight, which amounts to 6.7% PTWI. Both values point to the fact that the risk is low, even in the case of populations with high exposure to these toxic metals. This suggests that sustainable development may be possible in the near future

Assessment of the discharge regime and water budget of Belo Vrelo (source of the Tolišnica River, central Serbia)

A sufficiently long spring discharge regime monitoring data set allows for a large number of analyses, to better understand the process of transformation of precipitation into a discharge hydrograph. It is also possible to determine dynamic groundwater volumes in a karst spring catchment area, the water budget equation parameters and the like. It should be noted that a sufficiently long data set is deemed to be a continuous spring discharge time series of more than 30 years. Such time series are rare in Serbia. They are generally much shorter (less than 15 years), and the respective catchment areas therefore fall into the “ungauged” category. In order to extend existing karst spring discharge time series, we developed a model whose outputs, apart from mean monthly spring discharges, include daily real evapotranspiration rates, catchment size and dynamic volume variation during the analytical period. So far the model has solely been used to assess the discharge regime and water budget of karst springs. The present paper aims to demonstrate that the model also yields good results in the case of springs that drain aquifers developed in marbles. Belo Vrelo (“White Spring”, source of the Tolišnica River), which drains marbles and marbleized limestones and dolomites of Čemerno Mountain, was selected for the present case study. [OI-176022

Karst groundwater budget and discharge regime of Banja Spring near Petnica

Detailed hydrological and hydrogeological assessments of karst spring discharge require information about the groundwater regime in the study area/watershed. However, groundwater regime monitoring is often organized locally and sporadically, as required for specific studies or projects, and seldom lasts longer than one year. On the other hand, if time series of quantitative parameters are shorter than 15 years, the watershed is considered to be ungauged. As a result, discharge regime and karst aquifer budget assessments of ungauged watersheds can be misleading. To minimize water budget assessment errors, available time series need to be extended as far as possible. Regression models are commonly used to extend, simulate or fill gaps in existing time series. The paper presents an application of multiple linear regression to extend the existing time series of mean monthly discharges of Banja Spring (at Petnica, western Serbia), in order to cover the entire study period (1960-2006)

Synopsis of the project "Development of Professional Courses in Sustainable Water Management" - RESONATE Project

The project “Development of Professional Cours-es in Sustainable Water management” (acronym RESONATE) is a two-year project, from October 1, 2019 to September 30, 2021. It is funded by Er-asmus+. The aim of the RESONATE Project is to provide comprehensive engineering knowledge and develop professionals’ scientific, communication and problem solving skills through a combination of hands-on courses, industry projects and theo-retical background