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Ballesteros, D., Malard, A., Jeannin, P. Y., Jiménez-Sánchez, M., García-Sansegundo, J., Meléndez-Asensio, M., et al. (2015). KARSYS hydrogeological 3D modeling of alpine karst aquifers developed into geological complex areas: Picos de Europa National Park (Spain). Environmental Earth Sciences, , DOI 10.1007/s12665–015.
Résumé: Karst aquifers are valuable groundwater resources whose management requires the use of functioning hydrogeological models. The KARSYS approach provides an explicit 3D conceptual model of the geometry and the functioning of karst aquifers that has been successfully applied in Swiss and Slovenian aquifers. In this work, KARSYS is applied in a complex geological area: the Picos de Europa National Park (Spain). The hydrogeological 3D model (500 km2) shows an alpine karst aquifer compartmentalized into 32 groundwater bodies dammed up by subvertical barriers creating elevated saturated zones (water tables at 1153 m asl) and lower ones (water tables at 145 m asl). The recharge is through 18 spring catchment areas. The groundwater flows to the saturated zones pass through vertical to inclined trajectories, and phreatic flows are oriented toward NW, NE and N. KARSYS can be applied to any geologically complex area at a regional scale, although the geological structure should be simplified and the precision in some places is low.
Ballesteros, D., Malard, A., Jeannin, P. Y., Jiménez-Sánchez, M., García-Sansegundo, J., Meléndez-Asensio, M., et al. (2015). Influence of the rivers on speleogenesis combining KARSYS approach and cave levels. Picos de Europa, Spain. In Hydrogeological and environmental investigations in karst systems. Environmental Earth Sciences (Vol. 1, pp. 599–607). Springer.
Résumé: The influence of rivers on speleogenesis is studied analyzing the cave
levels located in the underground drainage areas related to two fluvial basins. Cave
levels are analyzed through their vertical distribution profiles. The underground
limits of the fluvial basins are defined using a 3D geometric model of the karst
aquifer established according to the KARSYS approach. The aim of this work is to
analyze the influence of the rivers on cave evolution using cave morphology. The
study area corresponds to the Western and Central massifs of Picos de Europa
(Northern Spain), with 214 km of cave conduits up to 1.6 km vertical range. As a
result, we established two sequences of development of the cave levels related to
the differences of the incision rate of the Cares and Dobra Rivers, and the partial
capture of the Western Massif by the Cares River.
Jeannin, P. - Y., Malard, A., Rickerl, D., & Weber, E. (2015). Assessing karst-hydraulic hazards in tunneling – the Brunnmühle spring system – Bernese Jura, Switzerland. Environmental Earth Sciences, 74(12), 7655–7670.
Résumé: Drilling a tunnel in a karst region requires the assessment of disturbances in the
hydrogeological functioning of aquifers and flow-systems as well as disturbances for
the tunnel itself. A complete characterization of the karst hydrogeological functioning
and the establishment of prevention measures are essential in order to insure a
suitable construction. The paper relates investigations which were conducted in the
frame of the construction of a safety gallery (Sisto) in the bernese Jura (Switzerland).
This gallery is located close to the outlet of a regional karst system and parallel to an
existing highway tunnel, which met numerous disorders in the past due to the
intersection of active karst conduits with a discharge reate exceeding 1 m3/s.
The KarstALEA method was applied along the Sisto trace in order to identify sections
with a high probability of karst occurrences and to characterize the type of karst related
problems. The main issue turned out to be related to water head and discharge, which
could potentially be cut by the tunnel construction. The system discharge rate may
frequently exceed 10 m3/s, and most of this water could potentially flow into the tunnel.
Therefore, a hydraulic model was set up in order to assess expected flow rates and
heads if conduits are intersected during the construction. Based on this model and on
meteorological and hydrological real-time measurements, a predictive model was
established in order to anticipate high-flows events.
Malard, A., Jeannin, P. - Y., & Rickerl, D. (2015). Impact of a Tunnel on a Karst Aquifer: Application on the Brunnmühle Springs (Bernese Jura,Switzerland). In Hydrogeological and environmental investigations in karst systems. Environmental Earth Sciences (pp. 457–463). Springer.
Résumé: Tunnel drilling in karst regions often leads to major disturbances in the hydrogeological functioning of
aquifers and flow-systems. Numerous examples in Switzerland do exist and induced significant costs,
which were not or rarely anticipated (e.g.: Flims, Jeannin et al. 2009). The Ligerztunnel is one such
example. The tunnel was built a few hundreds of meters upstream from the Brunnmühle spring, which
contributes to the drinking water supply of communities of Twann and Ligerz. During the construction, a
major karst conduit with a huge discharge rate was intersected in a side exploration tunnel. Overflowing
water was diverted in the Twannbach canyon. In the main section, smaller conduits were found and
drained outside by pipe leading water close to the Brunnmühle spring. Actually, authorities want to add a
safety gallery parallel to the main tunnel. In this view, SISKA is in charge of evaluating the hydrological
disturbances on the spring regime. The paper presents the approach applied to assess the potential effect of
the drilling of a new tunnel near to a group of karst springs and pumping wells. The approach combines
available spatial information and a hydraulic model. The KARSYS approach is first applied on the system
in order to set up a 3D geological and hydrogeological model of the karst aquifer and the related systems.
The spatial distribution of karst conduits within the massif is assessed based on a speleogenetical and
inception horizons model (KarstALEA method). Inferring from these models, a karst conduits network is
generated. The downstream part of the conduits network, which concerns the vicinity of the tunnels
project, is precisely calibrated using head and discharge data. Flow in this conduits network is then
simulated using SWMM 5.0 in order to reproduce the hydrological responses of the different outlets
(permanent springs, drainage devices, overflow springs, etc.).