In this paper we present the results of 3D conductive thermal modeling of the Alpine-Pannonian transition zone. The study area comprises the Vienna, Danube, Styrian and Mura-Zala basins, surrounded by the Eastern Alps, the Western Carpathians and Transdanubian Range. The model consists of three layers: Tertiary sediments, the underlying crust and lithospheric mantle. The crust and mantle were homogenous with constant thermal properties. Heat production in the sediments and crust was 1 lW/m 3. The thermal conductivity of sediments varied horizontally and vertically and based on laboratory measurements. We tested two scenarios: a steady-state and a time-dependent case. The conductive heat transport equation was solved by finite element method using Comsol Multiphysics. The results of the steady-state model fit to the observation in the northern part of the study area, but this model predicts lower heat flow density and temperatures than observed in the southern part of the study area including the Styrian basin. The area underwent lithospheric stretching during the Early-Middle Miocene time, therefore the temperature field in the lithosphere is not steady-state. We calculated the initial temperature distribution in the lithosphere at the end of rifting using non-homogeneous stretching factors, and we modeled the present day thermal field. The results of the time-dependent model fit to the observed heat flow density and temperatures, except in those areas where intensive groundwater flow occurs in the carbonatic basement of the Transdanubian Range and Northern Calcareous Alps, and the metamorphic basement high between the Mura trough and Styrian basin. We conclude that time-dependent model is able to predict the temperature field in the upper 6-8 km of the crust, and is a valuable tool in EGS exploration.

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Ideally, groundwater vulnerability assessment should take into account potential contaminant breakthrough curve, characterized by transit time, relative change of contamination concentration (input/output) and duration of overstepped concentration. Still, a majority of groundwater vulnerability assessment methods that tend to be more physically based count only with the value of mean transit time (MTT), the elapsed time when groundwater can exit the aquifer after its recharge. In this paper, indicative values of MTT derived from single d 18 O sampling values were used to estimate intrinsic vulnerability of individual springs occurring on the Muránska planina Plateau (Slovakia). For 295 springs sampled within 10 days, d 18 O was found in the range between -10.90 and -7.32 %, without signs of altitudinal effect. According to International Atomic Energy Agency (IAEA) Global Network of Isotopes in Precipitation (GNIP) stations, significant contrast in precipitation d 18 O values was found several weeks before sampling. Indicative MTT value, e max MTT (estimated longest possible mean transit time), was calculated from sine wave course of monitored precipitation isotopic composition, d 18 O value in the spring groundwater sample and altitudes of sampled point and precipitation station. Estimated e max MTT values suggest that heavier oxygen isotopes in samples probably reflect quick circulation and a more vulnerable environment as influenced by enriched summer precipitation. Depleted d 18 O suggests lower vulnerability represented by higher e max MTT values.

Bujnovský r., Malík p., Švasta J.: Evaluation of the risk of diffuse pollution of groundwater by nitrogen substances from agricultural land use as background for allocation of effective measures. Ekológia (Bratislava), vol. 35, no. 1, p. 66-77, 2015.The risk of diffuse pollution of groundwater by nitrogen substances from agricultural land is perceived as a result of the interaction of groundwater vulnerability (determined by the characteristics of the environment overlying groundwater in relation to water transport or soil solution) and loading of overlying environment by nitrogen. index of groundwater vulnerability was assessed on the basis of four parameters, namely, the amount of effective rainfall in the period from october to March, the capacity of soil to accumulate water, the average depth of the groundwater table and the permeability of the rock environment. assessment of the index of loading of overlying environment by nitrogen was based on two parameters, namely, nitrogen balance and crop cover on agricultural land in the winter half on districts level in 2012, which corresponds with current state of the load. The resulting risk of groundwater pollution by nitrogen was expressed by the formula counting with the transformed values of groundwater vulnerability index and the index of loading of overlying environment by nitrogen. From practical point of view, the above mentioned indexes, as well as the subsequent risk of diffuse groundwater pollution, were spatially expressed via three associated categories. Based on the evaluation of relevant parameters, 5.18% of agricultural land falls into the category of very high and high risk, 42.20% in the medium risk category and 52.62% in the category of low and very low risk of diffuse pollution of groundwater by nitrogen from agricultural land.

: Foreseen construction of a highway tunnel in the northern part of the Veľká Fatra Mts. (Slovakia) triggered the need for extensive hydrogeological investigations. The projected tunnel axis would cut through a large body buildup of Middle Triassic carbonate rocks. Dolomites and limestones with fissure–karstic permeability are surrounded by less-permeable marls, so that all springs dewatering this uplifted plate of carbonates are found above the erosion base on its edges. Detailed, hourly-based discharge monitoring of all four major springs was performed during the spring and summer period of 2014. In the meantime, groundwater table observations in two boreholes, located in the center of the fissure–karst aquifer, were run in the same time interval. Based on air temperature and precipitation records, the 2013–2014 winter period was practically without snow cover. In the middle of March 2014, an intense rainfall event caused a sudden rise of the groundwater table in the TK-04 borehole located in the southern part of the carbonate plate. Spreading of this singular hydraulic impulse throughout the structure was differently registered at individual springs within the time shift span of 1.38 to 65.25 days. Groundwater level rise of 0.40 m in the TK-04 borehole was postponed in 5.33 days. The response time of spring discharge to sudden groundwater table rise within the structure occurred later at springs with a higher water temperature. Water temperature differences between individual springs were still within the 2.46 °C narrow interval (5.57–8.03 °C). The vertical component of groundwater flux should play an important role even in a relatively simple, plate-shaped mountainous karstic aquifer fully uplifted above the erosional base, as was the case of the investigated Kopa Mt. hydrogeological structure.