Abstract
Ljubljansko polje and Ljubljansko Barje aquifers are the main groundwater resources for the needs of Ljubljana, the capital of Slovenia. Carbonate chemistry and isotope analysis of the groundwater were performed to acquire new hydrogeological data, which should serve as a base for improvement of hydrogeological conceptual models of both aquifers. A total of 138 groundwater samples were collected at 69 sampling locations from both aquifers. Major carbonate ions and the stable isotope of oxygen were used to identify differences in the recharging areas of aquifers. Four groups of groundwater were identified: (1) Ljubljansko polje aquifer, with higher Ca2+values, as limestone predominates in its recharge area, (2) northern part of Ljubljansko Barje aquifer, with prevailing dolomite in its recharge area, (3) central part of Ljubljansko Barje aquifer, which lies below surface cover of impermeable clay and is poor in carbonate, and (4) Brest and Iški vršaj aquifer in the southern part of Ljubljansko Barje with higher Mg2+ in groundwater and dolomite prevailing in its recharge area. The radioactive isotope tritium was also used to estimate the age of groundwater. Sampled groundwater is recent with tritium activity between 4 and 8 TU and residence time of up to 10 years.
Highlights
The Ljubljansko polje and Ljubljansko Barje aquifers are the two most important groundwater sources for Ljubljana, the capital city of Slovenia, and its surrounding area
New data on natural chemical composition of groundwater and its age were obtained. Groundwaters of both aquifers were separated into 4 main groups according to their hydrogeological and geographical position of sampling points (Figures 1–3): (I) groundwater of Ljubljansko polje, (II) groundwater of northern part of Ljubljansko Barje, (III) groundwater of middle part of Ljubljansko Barje, (IV) groundwater of southern part of Ljubljansko Barje— Brest and Iski vrsaj
Sava River water is depleted with δ18O due to its recharge area mainly from higher altitude areas
Summary
The Ljubljansko polje and Ljubljansko Barje aquifers are the two most important groundwater sources for Ljubljana, the capital city of Slovenia, and its surrounding area. Groundwater chemistry is an important factor determining its use for domestic, irrigation, and industrial purposes. It is being controlled greatly by interaction with mineral composition of the aquifer through which it flows. Groundwater has its unique chemistry due to several processes like soil/rock-water interaction during recharge and groundwater flow, prolonged storage in the aquifer, dissolution of mineral species, and so forth [2]. The groundwater chemistry of alluvial aquifers typically reflects the chemistry of the dominant rock type in the surrounding recharge areas. The available carbonates in these rocks are dissolved and added to the groundwater system by way of rainfall and irrigation infiltration and groundwater movement [4, 5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
