Jesús A. Uriarte

Geomechanical characterisation of rock masses in Alpine regions: the Basque Arc (Basque-Cantabrian basin, Northern Spain)

The geomechanical characterisation of rock masses in Alpine regions is one of the main challenges currently facing rock mechanics. These rock masses, made up of very different materials and frequently tectonically disturbed, are affected by engineering works, giving rise to potentially important problems. Thus, in the Basque Country, these materials are at the cause of important fatalities occurring in recent years. In this context, we aim at characterising these materials with the ultimate purpose of predicting their behaviour. The characterisation is initially approached based on the GSI, mi and σci parameters, following the Hoek-Brown failure criterion. This information is supplemented with field and laboratory measurements, and by obtaining the RQD and RMR indices. Using the information obtained from 99 metering stations, we develop a graphic classification procedure, which allows us to distinguish materials based on their characteristics, behaviour, type and degree of associated problems, and type and effectiveness of solutions provided. Eight classes of material are established.

Implementing a comprehensive approach for evaluating significance and disturbance in protected karst areas to guide management strategies

Many environmental studies have acquired an almost exclusively biotic perspective over the years, neglecting important key land characteristics like those of a geological and hydrological nature. This situation leads to incomplete, and even inappropriate, management strategies, particularly unjustified in the case of karst environments which form the basis of important protected areas around the world and are inherently very fragile environments compared to other natural systems. This study presents a holistic methodological approach to analyse the level of significance and disturbance in the Natural Park of Aralar (Basque Country, northern Spain) using two standardized indices: zonal Karst Significance Index (KSIZ) and zonal Karst Disturbance Index (KDIZ). The distribution of both indices in the park is based on the Geographic Information System (GIS). Thus, thematic maps regarding geological, geomorphological, biological, hydrological and cultural aspects provide the essential data for this work. The obtained results enable us to recognize the most significant and disturbed sectors of the park. These indices are subsequently combined to generate the Priority Management Index (PMI), which determine the different management needs of the territory. This comprehensive information not only serves efforts to better manage protected karst areas, but also to provide a snapshot view of the researched area to compare achieved results over time.