The sub-surface flow path through the Postojnska jama cave system has been monitored with 7 stations distributed along the flow path, monitoring stage and temperature. We have used the stage data to model flow through the cave system with the program package SWMM, simulating the active parts of Postojnska jama with simplified geometry. From the comparison of stage observations and predictions, we identified key sections in the cave, which control the sub-surface flow, such as passage constrictions, sumps and by-passes. Using a formal inverse procedure, we determined the geometry of this key sections by fitting predicted to observed stages, and we achieved a very high degree of correlation.
COBISS.SI-ID: 40739373
Based on the 30-year long period (1984-2013), in case of nine karst spring (rivers) the relation between discharge or water level, temperature and rainfall has been evaluated, using a time series analysis (autocorrelation and cross-correlation). The study has been conducted to qualitatively assess the applicability of long-term hydrological data sets usage in time series analysis in order to compare different karst springs and their catchments characteristics. The results revealed that typically, the storage capacity of larger systems and systems characterized by a more complex structure is greater which on the other hand does not by the rule mean that such systems are poorly karstified. In the study, factors influencing on the obtained results have been determined. Application of longer hydrological data sets proved to provide valuable information on hydrological properties of springs, hydrodynamic behaviour and hydraulic properties of their corresponding aquifers. However, caution needs to be taken when classifying karst systems into groups solely on the basis of the results of a time series analysis.
COBISS.SI-ID: 2750147
The review of the use of tracer tests in the Postojna and Pivka karst area was extended to the whole karst area in Slovenia. Characteristics of tracer tests were compared and their results were analysed. A case study within the project study area is presented. It confirms that the results of tracer tests enable better understanding of the influence of various recharge modes and the heterogeneous structure on the characteristics of water flow and solute transport in karst aquifers. Tracer tests are therefore an important tool for planning the use of karst water sources.
COBISS.SI-ID: 40276269