Northern Velebit (Croatia) karst hydrological system: results of a preliminary 2H and 18O stable isotope study

Scientific paper - Original scientific paper

• Author: Dalibor Paar; MBZ: 219211
• Author: Diana Mance; MBZ: 263524
• Author: Andrej Stroj; MBZ: 262896
• Author: Mirja Pavić
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Geology
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Interdisciplinary Natural Sciences

Abstract (english)

Researching the hydrogeological properties of karst systems is very challenging due to their ex- treme heterogeneity. A grey-box approach in karst research combines the results from classical hydrogeological methods with direct observations within the karstic underground, i.e. in the caves. Isotope research has become a widely used method in the investigation of karst systems. The results presented are of a preliminary 2H and 18O stable isotope study of the Northern Vele- bit karst system (Croatia) employing the grey-box approach. Groundwater samples were col- lected during two summer expeditions in deep caves within the karst massif. Monthly precipita- tion samples were also collected (at three locations between approx. 900 m and 1600 m altitude), as well as water samples at some of the most significant springs, i.e. discharge outlets of the system. For a single expedition, the stable isotope composition is almost constant, i.e. the stable isotope measurements are within the measurement error across the complete cave profile. Simi­ lar characteristics across different caves during the same year were also noted. Samples of wa- ter from the springs were taken during base-flow conditions and they have similar isotopic con- tents to the cave water. The results obtained indicate that homogenization of the water already occurs within the subsurface epikarst zone above the sampling locations in the caves, but a fu- ture extended sampling campaign during variable hydrologic conditions is needed to confirm this. The final research goal is to establish a conceptual grey-box model for the functioning of this complex hydrogeological system.

• Keywords (english): caves; hydrogeology; karst; Northern Velebit; stable isotopes
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Geologia Croatica
• Numbering: vol. 72, no. 3, pp. 205-213
• p-ISSN: 1330-030X
• e-ISSN: 1333-4875
• DOI: https://doi.org/10.4154/gc.2019.15
• URN:NBN: urn:nbn:hr:217:448242
• Publication: 2019
• Document URL: http://www.geologia-croatica.hr/index.php/GC/article/view/gc.2019.15
• Type of resource: Text
• Access conditions: Open access
• Public note: This work is licensed under a Creative Commons Attribution 4.0 International License. Manuscript received March 01, 2019. Revised manuscript accepted June 10, 2019. Available online October 31, 2019.
• Created on: 2020-08-18 17:24:20