20.500.12556/DiRROS-19205 Hydrogeochemical and isotopic characterisation of the Učja Aquifer, NW Slovenia Hidrogeokemična in izotopska karakterizacija vodonosnika Učje, SZ Slovenija The groundwater characteristics of the Učja aquifer were investigated using geochemical and isotopic data. The water discharge and physico-chemical properties of the groundwater and the Učja River reflect the climate that is characteristic of the area. The mixed snow/rainfall regime is characteristic for the Učja Valley, with the highest discharges appearing during the spring snowmelt and autumn precipitation, and the lowest discharges in the winter and especially summer months. The temperature of the groundwater and the Učja River is lower in winter and higher in summer. The specific electrical conductivity values indicate a very permeable carbonate aquifer. Higher conductivity values were observed in spring and autumn at all sampling sites, which is related to snowy and rainy periods. The groundwater from the Učja aquifer indicates a uniform type of water (Ca-Mg-HCO3), w it h Ca2+, Mg2+ and HCO3– the most abundant ions. Differences in Ca2+ and Mg2+ concentrations and in the Mg2+/Ca2+molar ratio between sampling sites were observed. Those springs with lower Mg2+ and lower Mg2+/Ca2+ molar ratios indicate limestone recharge areas, and those springs with higher Mg2+ and molar ratios indicate interaction with the dolomite hinterland. The pH values confirm alkaline waters characteristic of carbonate aquifers. The hydrogen (δ2H) and oxygen (δ18O) isotope values suggest the main source of water is from precipitation from a complex mixing of maritime and continental air masses. An altitude isotopic effect is observed with minor δ18O and δ2H depletion at higher altitude sampling sites compared to those springs at lower altitudes. The altitude isotopic effect is most prominent in spring. The δ13CDIC values indicate the dissolution of carbonates and the degradation of organic matter. Značilnosti podzemne vode vodonosnika doline Učje so bile raziskane z uporabo geokemijskih in izotopskih podatkov. Pretoki in fizikalno-kemijski parametri reke Učje in podzemne vode na izvirih odražajo podnebne značilnosti območja. Za dolino Učje je značilen mešani snežno-dežni režim z največjimi pretoki v času spomladanskega taljenja snega in jesenskih padavin ter najnižjimi pretoki pozimi in predvsem poleti. Temperatura podzemne vode in reke Učje je pozimi nižja in poleti višja. Rezultati specifične elektroprevodnosti kažejo na zelo prepusten karbonatni vodonosnik. Na vseh vzorčnih mestih so bile izmerjene višje vrednosti spomladi in jeseni, kar povezujem s snežnimi in deževnimi obdobji. Podzemna voda vodonosnika doline Učje je enotnega tipa (Ca-Mg-HCO3) z najvišjimi koncentracijami Ca2+, Mg2+ in HCO3– ionov. Med vzorčnimi mesti so bile ugotovljene razlike v koncentracijah Ca2+ in Mg2+ ter molskim razmerjem Mg2+/Ca2+. Izviri z nižjimi vrednostmi Mg2+ in nižjim molskim razmerjem izkazujejo apnenčevo napajalno območje, izviri z višjimi vrednostmi Mg2+ in višjim molskim razmerjem pa interakcijo z dolomitom. Vrednosti pH potrjujejo alkalnost voda, značilnih za karbonatne vodonosnike. Vrednosti izotopov vodika (δ2H) in kisika (δ18O) kažejo, da so glavni vir vode v vodonosniku padavine, ki nastanejo ob kompleksnem mešanju morskih in celinskih zračnih mas. Višinski izotopski efekt je opazen v nižjih vrednostih δ18O in δ2H na vzorčnih mestih višjih nadmorskih višin v primerjavi z izviri na nižjih nadmorskih višinah. Višinski izotopski učinek je najizrazitejši spomladi. Vrednosti δ13CDIC odražajo raztapljanje karbonatov in razgradnjo organske snovi. groundwater hydrogeochemistry isotopes cross-border aquifer Učja Valley podzemna voda hidrogeokemija izotopi čezmejni vodonosnik dolina Učje true false true Geološki zavod Slovenije Angleški jezik Slovenski jezik Neznano 2024-07-09 07:58:20 2024-07-09 07:58:20 2024-07-10 03:52:50 0000-00-00 00:00:00 2024 0 0 str. 7-24 no. 1 vol. 67 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2024-02-07 55 0016-7789 10.5474/geologija.2024.001 185507331 1873-Article_Text-12342512-3-10-20240207.pdf 1873-Article_Text-12342512-3-10-20240207.pdf 1 F872E7113332DB503077680B8240643D e5a65330286815dc6397f7a4ba5b32248f126cb8c8e047ee7899cb4c0c7692e7 a97be4b2-3db8-11ef-b487-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=26441 Geološki zavod Slovenije Geologija 0 0 0