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.).
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.