Naslov
Hydrogeological characterization of carbonate aquifer system in the northwestern part of Croatia

Autori
Marković, Tamara ; Larva, Ozren

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts Book / Lockington, David ; Cox, Malcolm - Perth, 2013, 179-179

Skup
IAH 40th International Congress

Mjesto i datum
Perth, Australija, 15.09.2013. - 20.09.2013

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
carbonate aquifer; yield; hydrochemical properties; northwestern Croatia

Sažetak
The mountains in north-western Croatia are partly built of permeable carbonate rocks with significant amounts of accumulated groundwater of exceptionally good quality. Although the yield of these aquifers is significantly lower than those of Dinaric karst region, they still represent valuable sources of drinking water. An example is Mt. Ivanščica, which is the highest mountain in the area (1061m a.s.l). It is built of rocks ranging in age from Palaeozoic to Quaternary. Middle and upper Triassic carbonate rocks, dolomite and limestone, are the main aquifers. Lithotamnium limestones of Miocene age and Quaternary sediments also belong to the group of permeable rocks. The group of generally impermeable rocks includes Carbon-Perm sediments (clastic deposits), Triassic sediments (silt, shale and sandstones), as well as Cretaceous and Miocene clastic sediments. There are four major springs (Šumi, Beli Zdenci, Bistrica, Žgano Vino) on the northern slope of Mt. Ivanščica (Ivanec area). On the southern slope (in Lobor area) three major springs (Škrabutnik, Koprivnjak, Šumeci) were formed and three boreholes (Lo-1, Lo-4 and Lo-5) have been drilled. The springs and Lo-1 borehole are tapped for public water supply. In the Ivanec area, the highest mean yield has Bistrica spring – 60 l/s and the lowest Beli Zdenci spring - 4 l/s. In the Lobor area, springs have generally lower capacities ranging from 0, 6 l/s (Šumeci spring) to11 l/s (Koprivnjak spring). Significantly higher capacity has the well Lo-5 with 70 l/s of artesian discharge. In period from 2007 to 2012 the hydrogeological monitoring was carried out on the springs and boreholes. According to chemical composition of the sampled waters, they belong to the CaMg-HCO3 hydrochemical type. The measured yields do not show large oscillations. Water temperatures of springs and boreholes do not show large oscillations as well and indicate good mixing of freshly infiltrated water with base flow and homogenization in the catchment area. Very low concentrations of nitrate, sulphate and chloride were observed, while concentrations of ammonium and phosphate were below detection limit. The stable isotope ratio points to the recharge of springs by precipitation. The tritium content indicates the long circulation time of groundwater but also the replenishment by precipitation.

Izvorni jezik
Engleski

Znanstvena područja
Rudarstvo, nafta i geološko inženjerstvo

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