The Ljubljansko polje aquifer, which is the main supply of drinking water for the local population in Ljubljana, Slovenia is highly vulnerable to anthropogenic pollution. In this study, the ...geochemistry of major constituents including nitrate concentrations and the dual isotopes of nitrate were used to ascertain the spatial distribution of processes and nitrate sources in the groundwater from seven wells at three different water supplies: Kleče, Hrastje and Jarški prod. The groundwater is of the Ca2+-Mg2+-HCO3− type approaching equilibrium with respect to dolomite and are moderately supersaturated with calcite. The groundwater nitrate concentrations ranged from 5.32 to 50.1 mg L−1 and are well above the threshold value for anthropogenic activity (3 mg L−1). The δ15NNO3 values ranged from 1.4 to 9.7‰, while δ18ONO3 values were from 6.3 to 34.6‰. Based on isotope mixing model three sources of nitrate were identified: atmospheric deposition, fertilizers and soil nitrogen. At Kleče 8, Kleče 12 and Jarški prod 3 the low δ15NNO3 and high δ18ONO3 values result from pristine nitrate sources, while in Hrastje 3 and Kleče 11 equal amounts of nitrate derived from soils with mixed fertilization and sewage. The data also indicate that the main sources of high nitrate concentrations in groundwater are from fertilizers and sewage-manure (comprising up to 64%). Such levels occurred in the Hrastje and Kleče 11 wells where precipitation is the main source of groundwater. Nitrate derived from atmospheric deposition accounted for approximately 10% of the nitrate in the groundwater. The message from this study is that to reduce the nitrogen load and improve water quality will involve containment and the careful management of sources from urban and agriculture inputs such as sewage-manure and fertilizers.
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•Groundwaters in Ljubljansko polje aquifer are Ca2+-Mg2+-HCO3− waters.•The main sources of nitrate are atmospheric deposition, fertilizers and soil nitrogen.•Sewage-manure nitrate is important at locations where precipitation is the main source of groundwater.
In this paper, we present an assessment of the sensitivity of groundwater-surface water interactions to climate change in an alluvial aquifer, located in the Ljubljansko polje, Slovenia. The ...investigation is motivated by a recent assessment of climate change pressures on the water balance in the Sava River Basin (Gampe et al., 2016). The assessment was performed using a comprehensive hydrological modelling approach, which is based on the direct/indirect communication between FEFLOW and WaSiM/MIKE 11. This modelling framework provides a precise simulation of the critical processes in the study domain, which are the main drivers influencing the interactions between precipitation, river water and groundwater under different future climate scenarios. Climate projections were based on the results of the three regional climate models SMHI-RCA4, KNMI-RACMO22E and CLMcom-CCLM4. The results show that there will be higher levels of local precipitation during 2036–2065, the projected river discharge will be larger in the future compared to 2000–2014, and it is unlikely that the Ljubljansko polje will suffer from water scarcity. In addition, amongst the various sections of the Sava River the section between Črnuče and Šentjakob is the one most sensitive to climate change. By running the models under different climate scenarios a deeper insight into aquifer system functioning was obtained. Investigating impacts of climate change on groundwater and interactions between surface water and groundwater on the local scale is a basis for applying such a study on the global scale, which was still not very well investigated.
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•Impacts of projected climate on surface-groundwater interactions are presented.•The aquifer's sensitivity to the climate is higher if one water source dominates.•The Ljubljansko polje is not going to suffer due to water scarcity (2036–2065).•A comprehensive modelling tool approach was applied.
Urban areas can significantly alter the quality status of aquifers if appropriate strategies to prevent and detect groundwater contamination are not implemented in time. The prevention of groundwater ...contamination should be a priority due to its potential long-term impact on the environment and the high cost of remediation. For effective and sustainable groundwater management, it is crucial to proactively monitor a wide range of compounds to prevent their spread, progression and increasing concentrations. This study is one of the few to analyse the trends of various urban groundwater contaminants (nitrate, sulphate, hexavalent chromium, pesticides, PCE and TCE) from a groundwater management perspective. Characteristic trends are assessed using linear regression and the Mann–Kendall method, while significant changes in trends are determined using the Darken and Pettitt tests. The time span of the analysed trends covers the transition period before and after the implementation of the Water Framework Directive (2000/60/EC) and the Groundwater Directive (2000/60/EC). This study confirms the effectiveness of enforcement measures to protect groundwater quality, as evidenced by several statistically significant decreasing trends. On the other hand, this study emphasises the importance of intervention-targeted sampling campaigns and the reporting of raw analytical values according to the ISO 11843 series of standards. This approach is essential to detect upward trends in emerging contaminants at an early stage and prevent them from reaching levels that could negatively impact the economy or even jeopardise the safety of drinking water supplies.
Groundwater is an important resource for drinking water. Although it is a relatively stable and protected water resource, its quality, especially in highly urbanized catchments, is vulnerable to ...pollution related to unusual events or accidents causing releases of hazardous substances. To ensure the safe supply of drinking water in these cases, prompt actions must be taken and solutions must be delivered under time constraints. This paper describes a decision support system for emergency groundwater management that was developed to improve activities after the discovery of pollution in the catchments of drinking water abstraction wells in the Ljubljansko polje aquifer. It is a system based on a monitoring network and the integration of numerical modeling techniques with expert knowledge. The integration of logically interlinked activities, including the detection of pollution in the groundwater, the simulation of pollution propagation and decision making, into a common system provides a basis for proactive water resource management. The user-friendly interface enables water managers to utilize modeling tools and rapidly access information for mitigating pollution of groundwater resource, which in the presented case significantly contributes to a safer drinking water supply.
This volume (‘Former waste disposal sites in dolines and gravel pits’) presents former waste disposal sites in depressions (dolines and gravel pits) using relief analysis of the former and current ...landscape and based on comparing them with one another. A comprehensive methodological approach has been created called the three-dimensional (3D) model, which is used to detect and record unknown, hidden former waste disposal sites in depressions above sensitive aquifers. The research deals with the problem of former waste disposal sites from the viewpoint of discovering them, creating a registry, and studying noticeable surface effects on the landscape (relief, soil, and vegetation).
The extensive groundwater reserves in the Ljubljana Plain, estimated at 100 million m3, represent a natural resource of regional significance. The Decree on the Protection of Sources of Drinking ...Water divides this water protection area into three drinking-water protection zones. The area is exposed to possible pollution by many activities, among which agriculture is especially problematic because it is not supervised strictly enough. The majority of farms are engaged in traditional animal husbandry, of which cattle breeding dominates.
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