Karstology and the opening of caves during motorway construction in the karst region of Slovenia

Abstract

The nature of karst makes constructing a roadway across karst areas a complex task, which is why karstologists take part in motorway construction across Slovenia’s karst. Working with planners, karstologists select the best route on the basis of preliminary research. Then they carry out regular karstological monitoring of the construction, to study newly discovered karst phenomena, mostly caves, and also help builders overcome the challenges of karst in a way that will preserve nature as much as possible. During the recent construction of a section of motorway, more than three hundred caves were encountered within a sixty-kilometre stretch of road. Varied tectonic and lithostratigraphical conditions make it even more difficult to predict the cave locations in advance. Various types of cave reflect the development of the aquifer due to the lowering of the groundwater level and of the karst surface. All caves are explored, and the sediments and flowstone in them studied, in an attempt to preserve the most important ones. Caves are an important part of Slovenia’s natural heritage, and research contributes new knowledge about the morphology and development of the karst region. Knowledge of unroofed caves and their traces on the karst surface provides a distinct advantage in planning new road sections. Expertise derived from recent experiences enables these features to be detected on the karst surface before the earth moving begins.