PYRMOVE: managing the risk of landslides in the Pyrenees

Starting in 2016, local stakeholders on the French and Spanish sides came together to create a project examining land movement in the Pyrenees. That issue hadn't previously been analyzed or tackled. Together we built a program known as the PyrMove project to examine land movement triggers in the event of heavy rainfall and to study major landslides that can impact infrastructure. The problem of landslides here in Val d'Aran is a big one that occurs regularly. So studying and creating an early warning system is vital for public safety. The idea was to promote studying the risk related to land movements as a specific risk. It is very prevalent in the Pyrenees. The risk is often studied and is often associated with rainfall. One aim of this project was to look at this risk as separate from flood risks, for example. The project's second objective was to study a range of sites to assess the risk and come up with ways to reduce it. The Catalonia Institute of Cartography and Geology became involved in communications and other work on the project, but on a technical level. We focused mostly on characterizing regional landslides and other land movement episodes. These landslides affect roads, hindering the passage of emergency and evacuation services. So it's important to know when they will occur and ensure that emergency and first aid services will know what to expect and be able to get to where they need to be. For an overall understanding of how landslides develop and the shifts involved, we need to monitor deformation and displacement along with water levels, which are always the driving force behind these movements, so we can determine the thresholds that correspond to sudden accelerations and will allow us to make decisions about how best to protect the population. Of the three sites, two are in France. First is Viella, where a village is located, a site that is studied by a group of experts for the French government. There are several studies. One is an assessment on behalf of the Prefect to inform him about the development and evolution of land movements, which was prompted by the major flooding in June 2013 in Bastan. Alongside that is more scientific work: instrumentation, setting up inclinometer sensors and piezometers, and time-tracking movements. That is the subject of research in association with BRGM and the ONF's RTM services. The second site is Gourette, which was chosen because of the associated risks, particularly the presence of a ski resort and a main road. We set up a dozen GPS terminals. We also drilled five wells to monitor groundwater levels and a rain gauge to track precipitation. The purpose of this instrumentation is to obtain long-term data so we can track landslide activity. The minimum period is five years. The third site is in Andorra: the Canillo site. It's known as one of the biggest landslide sites in the Pyrenees, threatening a water inlet channel at the power plant supplying Andorra. We take part in all the actions, except the last one, MORLEs. We collaborate by contributing local knowledge of the region. For example, as we are one of the study areas of the Canillo movements in Andorra, all the knowledge generated by the project is valuable both for civil protection and geological knowledge of the movements. Another aspect of the project is cross-border cooperation. We are a small country, so working with neighbors who face the same problems means more information and knowledge transfer. Today, at the invitation of the Val d'Aran community, we presented educational tools, or software and software packages so a municipality can show its citizens and various managers how these phenomena occur and what triggers an earthquake, water, floods, etc., and see the broad connection between disaster events in the high valleys. Using the tools developed for this project, we now have landslide susceptibility maps, which indicate areas of the region that are susceptible to landslides as well as a simulator for MORLEs, or massive events. In today's workshop, we showed administrators and technicians how to use these tools. As well as in-person groups, we had online participation with simultaneous interpretation from Spanish to French. During the project, one of the partnership's commitments was to publish details and raise public awareness of the dangers posed by major land movements. To reinforce this idea, we decided to create a monograph, or a book, which is one of the results of the project. We hope it becomes bedside reading for authorities and those working on land management. All the studies carried out as part of the PyrMove project and the techniques developed are rapidly applicable. The important thing now is to find financing so that the theoretical and practical knowledge gained can be directly applied to prevention management. The project was a success in terms of methodology development and tool transfer to communities. We hope it carries on in the context of future calls for projects in order to pursue this issue in the Pyrenees.