1281. Hydrogeological characterization of karst springs of the white (Proteus anguinus anguinus) and black olm (Proteus anguinus parkelj) habitat in Bela krajina (SE Slovenia)Katja Koren, Rok Brajkovič, 2023, izvirni znanstveni članek Povzetek: The springs west of Črnomelj, in SE Slovenia, are the habitat of the black (Proteus anguinus parkelj) and the white olm (Proteus anguinus anguinus). Some of these springs are also the only known habitat in the world of endemic species of black olm. A steady decline in olm populations has been observed in this area over the past decades. Owing to the rapid runoff and groundwater flow high-resolution monitoring is essential in providing better insight into the hydrogeological characterization of the catchment area of springs. Specific factors and critical parameters of water behind said olm degradation have not yet been defined. Because the olm’s environment is largely aquatic, one potential critical parameter could be the higher water temperatures (>12 °C) or higher nitrate concentration (>9.2mg/l). The six-month observation of the springs (July – December 2021) point to water temperature as a potential critical parameter since the water temperature of the springs exceeded 12 °C in months July and August. Nitrate concentrations could also be a second critical parameter in the degradation of the olm’s habitat. Maximum nitrate concentrations above 9.2mg/l throughout much of the observation period (except for Dobličica spring). Due to less agricultural activity in December in the spring catchment area and a higher dilution rate due to reduced evapotranspiration and increased effective precipitation during this time of the year, the nitrate concentrations are decreased. The results of the measured parameters of groundwater could show the hydrogeological connection between the Otovski and Pački breg springs and between Šotor, Jamnice and Dobličica. The Obršec spring has an independent catchment area. A detailed estimation of the springs catchment area is possible due to a detailed geologic map. It is necessary to determine the origin of the nitrate (nitrate isotope analysis), to quantify the threshold values of the critical parameters, to define precisely all the causes of the olm deterioration, and to make proposals for appropriate measures to limit or even stop the decline of the olm population.
Ključne besede: hydrogeology, olm, ecology, nitrate, monitoring
Objavljeno v DiRROS: 16.01.2024; Ogledov: 282; Prenosov: 93
 Celotno besedilo (13,65 MB) |
1282. Impact assessment of the Gajke and Brstje landfills on groundwater status using stable and radioactive isotopesSonja Cerar, Luka Serianz, Polona Vreča, Marko Štrok, Tjaša Kanduč, 2023, izvirni znanstveni članek Povzetek: Waste disposal in landfills represents a severe threat to aquatic environments on the local, regional, and global levels. In Slovenia, there are 69 registered landfills where groundwater is regularly monitored. However, isotope techniques are not regularly employed. Therefore, we employed isotope analysis of hydrogen, carbon, and oxygen in combination with total alkalinity to assess the impact of the selected landfill on groundwater and to evaluate the biogeochemical processes at work. The δ18O, δ2H, δ13CDIC, 3H activity and total alkalinity were determined in October 2020 at 12 sampling points from the surrounding area of the Gajke and Brstje landfills and leachate from the Gajke landfill. The δ18O (-9.24 ± 0.3 ‰) and δ2H (-64.9 ± 2.7 ‰) in groundwater indicate that the main water source consists in direct infiltration of precipitation, with no significant isotopic fractionation. Total alkalinity in the investigated area ranges from 5.45 to 73 mM and δ13CDIC from –14.9 to +6.1 ‰, respectively. Higher values of total alkalinity (up to 73 mM), δ13CDIC (up to +6.1 ‰), δ18O (-7.64 ‰) and 3H (209.8 TU) are detected in the leachate, indicating biogeochemical process related to CO2 reduction or methanogenesis. Methanogenesis could be present at locations GAP-10/13 (Brstje landfill) and G-2 (Gajke landfill) with δ13CDIC values ranging from –8.2 to –7.6 ‰ and with dissolved oxygen values around 0 % and elevated 3H values (from 16 to 18 TU). This study demonstrates the effectiveness of isotopic analysis as a valuable tool for monitoring landfills, revealing shifts in biogeochemical processes within the groundwater there.
Ključne besede: groundwater, monitoring, landfill, stable isotopes, tritium, Gajke, Brstje
Objavljeno v DiRROS: 16.01.2024; Ogledov: 325; Prenosov: 110
Celotno besedilo (8,52 MB) |
1283. Using Ground Penetrating Radar (GPR) for detecting a crypt beneath a paved church floorMarjana Zajc, Alojzij Grebenc, 2023, izvirni znanstveni članek Povzetek: After the discovery of an archive document regarding an underground crypt beneath the f loors of the Church of St. Margaret (Sv. Marjeta) in Dol pri Ljubljani, Slovenia, further research was carried out to confirm its presence. An area filled with construction waste was discovered during a recent small-scale renovation of the church floor. This finding suggested the potential underground chamber may have been partly filled in during one of the previous restorations. A non-invasive GPR study was carried out along eight profiles inside the church to prove the existence of an underground crypt. Results show the presence of an air-filled chamber, confirmed later by a hole drilled in the floor. Additional findings in the church archive and pictures taken by a camera, lowered through a drilled hole, revealed three previously unknown caskets in the crypt. According to the archives, two of them belong to Baron Wolf Daniel Erberg and his wife who died in 1783 and 1774, respectively.
Ključne besede: Ground Penetrating Radar (GPR), church Sv. Marjeta, crypt, underground chamber, Baron Erberg, Dol pri Ljubljani
Objavljeno v DiRROS: 16.01.2024; Ogledov: 347; Prenosov: 69
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