In this contribution we present the work carried out for monitoring the displacements of Vallcebre landslide (Eastern Pyrenees, Spain) between 1987 and 2012. The landslide, which extends over an area of 0,8 km2 and involves more than 20 million cubic meters, has experienced displacements as large as 1 m per year in some points. It has been periodically monitored since 1987, using a wide range of surface and in-hole techniques, successively: triangulation with theodolite, Terrestrial Photogrammetry, Electronic Distance Measurement, GPS, inclinometers, wire extensometers, piezometers, DInSAR and GBSAR. The results using the new techniques have been compared with those obtained with the GPS and the wire extensometer, and checked against fixed stable points. From this comparison, we conclude that even though wire extensometers and inclinometers may have the highest precision, in practice all the systems have their own role in providing meaningful data for the monitoring at different study stages. After the evaluation of the precision and advantages of the different methods, the complementary use of some of them is strongly recommended.

Slow-moving landslides yearly induce huge economic loss worldwide in terms of damage to structures/infrastructures and interruption of human activities as well. Within the landslide risk management framework, the vulnerability analysis is a key step entailing procedures mostly based on the identification of the exposed elements, the damage classification and the definition of an intensity criterion. The present paper introduces a two-scale procedure for the analysis of building vulnerability to slowmoving landslides. The intensity parameter (i.e. absolute or differential settlement) derives from the information provided by Differential Interferometric Synthetic Aperture Radar (DInSAR) satellite data, which in the last decade proved to be capable of providing cost-effective long-term displacement archives of structures/infrastructures. The obtained results over two slow-moving landslideaffected areas allowed the generation of empirical fragility curves for masonry buildings that, once further validated, can be valuably used for damage analysis and forecasting.

The paper presents the experience of two instrumented sites in the Pyrenees where debris flows and rock falls occur frequently. The first one is the debris-flow monitoring system in the Rebaixader catchment, Central Pyrenees, Spain, installed since summer 2009. It consists of sensors registering meteorological and infiltration data as well as geophones, radar, ultrasonic sensors and a video camera focusing on the detection and dynamics of the flows. 24 torrential flows (debris flows and debris floods) and also 5 block falls have been detected. The second site is a recently installed rockfall monitoring system at the Forat Negre couloir, in Andorra la Vella, Principality of Andorra. It consists of 5 geophones and a video camera. For the same area high resolution point clouds obtained by remote techniques such as digital photogrammetry and Terrestrial Laser Scanner additionally permit the assessment of rockfall volumes and geometry, overcoming access restrictions.

Long-term field monitoring of slopes prone to shallow landslides can be a fundamental tool for the identification of failure conditions. The aim of this work was the development of a field monitoring system able to integrate different meteorological and hydrological tools, in order to enhance both frequency and quality of measurements. The equipment was installed on a slope susceptible to shallow landslides in north-eastern Oltrepò Pavese (Northern Italy). Some expedients were established to improve the interpretation of field data. This allowed for checking the accuracy of the data and obtaining a reliable comprehension of the soil-atmosphere interaction mechanisms. This approach can lead to a better identification of shallow landslides triggering conditions, in terms of both the failure mechanism and the occurrence time.

Synthetic ground motion parameters are usually adopted for the characterization of seismic signals, because of their effectiveness in synthesize the main information about amplitude, frequency and duration of earthquakes. The influence of focal mechanism on ground motion parameters and the differences or similarities for areas characterized by different prevalent faults will be discussed in this paper. The main aim of the study is to clarify the possibility of utilization of spectrum compatible accelerograms independently by their fault typology, to derive a set of design accelerograms for advanced structural and geotechnical analyses in given areas. Particularly, it will be demonstrate that care should be taken, because neglecting the source mechanism might lead to the loss of important information (i.e. duration and frequency content) about ground motion nature itself.