UIS Commission on Karst Hydrogeology and Speleogenesis
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Karstbase Bibliography Database

Modelling the evolution of karst aquifers in three dimensions/conceptual models and realistic scenarios inaugural dissertation/ zur erlangung des doktorgrades dr. rer. nat. am fachbereich geowissenschaften im institut fur geologische wissenschaften der fr

This work presents the development of three dimensional karst evolution models for various settings and conditions. As karst aquifers are very sensitive to changes of their hydraulic boundary conditions a comprehensive understanding of the governing processes inside a karst aquifer is indispensable. Especially if a karst aquifer is inuenced by anthropogenic utilization like e.g. the construction of a dam site, the resulting changes inside the aquifer need to be understood as good as possible to prevent any unpredictable incidents. The use of numerical models to simulate the development of a karst aquifer is therefore a suitable tool in the preliminary investigations. It will be shown that simple three dimensional damsite models can be used to evaluate the parameters that control the karst aquifer evolution. Based on these simple models an enhanced three dimensional model of a real damsite is developed. This model is used to simulate the evolution of the aquifer close to this damsite and to expose how the construction of the dam inuenced the nearby bedrock signicantly. It is shown that the karstied zone around the dam site is the reason for the subsidence of an adjacent highway. The presented numerical results can be veried by eld observations. Additionally to the damsite models a three dimensional model approach is presented that describes the formation of large collapse dolines. Collapse dolines are signicant surface features of karst landscapes and their evolution which is usually linked to a subsurface karst system is of high interest in the karst community. To simulate the evolution and interaction of such a doline system, a three dimensional model with several spatially distributed dolines is used. There, based on the concept of a mechanically weakened crushed zone, the evolution over time is presented. The applied collapsing mechanism used in this work also allows to estimate the bedrock removal and surface lowering over time. The determined rates are in good agreement with values reported in literature

EVOLUTION OF KARST AQUIFERS, threedimensional karst evolution models, dam-site models a three-dimensional model