Hydrogeological characterization of groundwater storage and drainage in an alpine karst aquifer (the Kanin massif, Julian Alps)

Abstract

The Kanin massif is an important trans-boundary aquifer, which stretches between Slovenia and Italy. The groundwater is only partially exploited, mainly for water supply, but the aquifer exhibits great potential for future exploitation. Since no consistent regional overview of the hydrogeological functioning of the Kanin massif was available, the decision was made to perform a study of this area, using a pragmatic approach based on 3D geological and hydrogeological modelling. The so-called KARSYS approach was applied, with the aim of characterizing the groundwater reserves within this karst massif, and of locating the main drainage axes which carry groundwater from the recharge areas to the respective springs.Delineation of the catchment areas of the corresponding springs was carried out, and some new explanations were obtained, especially with regard to the Možnica spring, which is located in Slovenia and forms a potential source of drinking water. It was found that this spring's catchment area extends as far as the Italian ski resort of Sella Nevea. The conceptual model also provides a possible explanation about the underground drainage toward the Boka spring and waterfall, which has been a challenge for decades. This new explanation is based on the existence of a perched groundwater body, which feeds the Boka spring via a system of conduits. Despite some limitations, the results, which consist of a visualization of the underground drainage and groundwater storage within the Kanin massif, can be used as a basis for planning the sustainable management of karst waters in the studied area.

A 3D geological model of a structurally complex Alpine region as a basis for interdisciplinary research

“…Although the conclusions of this speleological prospection broadly concord with our hydrogeological expectations drawn from the lithological descriptions, they do highlight the issue of chemio-mineralogical purity, and more specifically the possibility that the degree of karstification in our study area may not be as high as elsewhere in the Helevetic zone. In any case, a benefit of our approach – of only estimating formation geometries initially – is that in contrast to the methodology followed by other authors 8 , 10 , there is no need to definitively categorise each formation as being either an aquifer or aquiclude initially; reality is certainly not this binary. Rather, it is our intention to vary and hopefully constrain parameters representing the hydraulic properties of the various formations during subsequent numerical model calibration.…”

Vulnerability mapping and protection zoning of karst springs. Validation by multitracer tests

“…Karst aquifers are particularly sensitive to contamination, having a very low self-cleaning capacity due Action 620 recommendations and EPIK, the first method specifically designed for karst vulnerability mapping, (Dörfliger and Zwahlen, 1997), many other methods for vulnerability assessing and mapping have been developed, such as: PI (Goldscheider et al, 2000), KARSTIC (Davis et al, 2002); COP and COP + K methods Andreo et al, 2009), the Slovene Approach (Ravbar and Goldscheider, 2007), or PaPRIKa (Kavouri et al, 2011). Geographic information systems and GIS-based approaches are widely used for the intrinsic vulnerability mapping of karst aquifers, although there are also relevant advances in geological and hydrogeological modeling for karst systems (Jeannin et al, 2013;Hartmann et al, 2014;Turk et al, 2014).…”

The Role of Snowmelt on the Spatio-Temporal Variability of Spring Recharge in a Dolomitic Mountain Group, Italian Alps

“…Often, previous works focused on single catchments and/or a few springs or groundwater wells, and very little is known about how snowmelt contributions to spring water vary in space (including along elevation gradients) and time (over seasons and years) at the scale of an entire mountain group. Even less knowledge is available on the role of snowmelt in feeding springs in karst mountain groups and catchments, where the network of fractures and conduits strongly influences the infiltration processes [28][29][30] and make the hydrological response pretty complex [31].…”