Abstract
Karst ground water dynamics between the Planinsko polje and the springs of Ljubljanica (Slovenia) was studied based on the monitoring of stage and temperature of ground water in four caves. The Unica River, which flows over the Planinsko Polje, and sinks at its E and N rim, is considered as the main input to the observed system. At small flood events its role is none or questionable. At medium and large events, when the discharge of Unica exceeds 25 m 3/s, it becomes an important and/or the dominant input to the system. When the capacity of the primary (eastern) ponors in the polje is exceeded, the stage in a cave, which is fed solely through these ponors, reaches the plateau followed by a very slow recession. The surplus flow goes towards northern ponors causing a fast rise of the stage in adjacent to them. In two of the northernmost caves, the stage response is almost identical, but the temperature variations are different. The uniform water level suggests a highly permeable region bounded by a low permeability barrier in the down-flow direction, while different temperature behavior indicates a different origin of the waters for each cave.
Highlights
The springs of the Ljubljanica River drain more than 1100 km2 of karst area in central and south-east Slovenia (ŠUŠTERŠIČ, 2000)
The loggers were relatively remote in the caves, Gabrovšek and Turk: Observations of stage and temperature dynamics in the epiphreatic caves within the catchment area of the Ljubljanica river (Slovenia) their autonomy was important to avoid too many trips; 30 min intervals with 24000 readings gives 16 months recording before the logger’s memory is full
A fast response in Najdena Jama is followed by slow recession. Such a response could be caused by local runoff from the neighbouring Planinsko Polje or a fast flow of autogenic origin
Summary
The springs of the Ljubljanica River drain more than 1100 km of karst area in central and south-east Slovenia (ŠUŠTERŠIČ, 2000). The catchment comprises a vegetated karst surface and a series of karst poljes, including the periodically flooded Cerkniško and Planinsko poljes. Water from the poljes flows underground towards the springs of Ljubljanica, at the rim of the Ljubljana Basin. Intensive hydrogeological investigations of the area have been carried out for more than a century. HABIČ (1976) have shown clear connections between the ponors and springs. A more detailed picture of groundwater dynamics in the aquifer is still needed. Part of the system, related to this study, is shown on Fig. 1
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
