Hydro-geophysical observations for an Advanced Understanding of Clayey Landslides

As a consequence of climate change and, thus, in hydrological cycles, the risk of landslides is growing worldwide. Therefore, there is an urgent demand of a short-time landslide prediction tool towards risk mitigation. Here, we propose a multidisciplinary approach which consists in the development of hydrogeological and geophysical measurement and interpretation techniques for the real-time monitoring of processes in landslides. To achieve this, our approach combines the implementation of emerging technology combined with advanced numerical modelling. The advantage of the approach here proposed is that our monitoring system permits the collection of hydrogeophysical data with high spatio-temporal resolution, but over long time continuous monitoring, as required to understand the deformation and triggering factors in landslides. We propose the application of the Induced Polarization (IP), an extension of the electrical resistivity method, to delineate the occurrence of clay minerals, which are characterized by a characteristic IP response. For a better interpretation of the IP imaging results and to understand the landslide triggering mechanism before the onset of a displacement, additional parameters have to be monitored. Typical approaches consider GPS receivers and total station benchmarks at the surface, or inclinometers at depths, which provide only punctual 1D information, but have limitations at high displacement rates. To solve interpretation ambiguities, but also to account for spatial changes, in our proposal we consider horizontally and vertically (borehole) distributed displacement/strain measurements. In addition to this, new approaches will be applied, namely temperature and strain monitoring at high frequency with Fiber-Optic (FO) cables both at the surface and in boreholes and sensing of surface deformation with Ultra-High Resolution (UHR, 20 cm) optical images. The combined application of these methods for landslide monitoring is very rare. Coupled multi-physical modelling simulations to gain the understanding of underlying processes will support the joint interpretation of available monitoring datasets. Our proposal benefits from the European landslide-monitoring network established in 2009 by the Geological Survey of Austria (GSA) in collaboration with national and international partner such as the French Observatory on Landslides (OMIV), established by the National Centre of Scientific Research (CNRS). In this regard, the project account with significant amount of information, collected over the last years to calibrate and evaluate predictions resulting from models developed in our investigations. The co-application in this proposal by the GSA and CNRS provides continuity to this international and multidisciplinary approach, but also permits to involve other research institutions, such as the Vienna University of Technology (TUW) to contribute in relevant investigations and the knowledge transfer.

No additional funding sources recorded.