The two selected test-sites are located in Canary Islands (Spain) and Valle d’Aosta (Italy). In the first site, both the volcanic and rockfall early-warning will be tested. In the second, the methodology will be applied to landslide geohazard.
Canary Islands is a populated outermost Spanish region and one of the most popular touristic destinations in Europe. More than 2 million people live and work in the 7,447 km2 of the archipelago, resulting in an average population density three times greater than the rest of Spain. The archipelago is one of the major volcanic oceanic island groups of the world and have a long magmatic history, which began at the bottom of the ocean more than 40 million years ago (Araña and Ortiz, 1991). This volcanic archipelago is constructed on the passive continental margin of the African Plate on Jurassic oceanic lithosphere and comprises seven main volcanic islands that form a chain extending for some 500 km across the East Atlantic
Ocean (e.g. Carracedo et al., 2002). Most of the historical eruptions in the Canary Islands have been short lived from few weeks to few months) basaltic, strombolian to violent strombolian eruptions, which have generated scoria cones of different sizes and lava flows of different extend (Romero, 1991). The volcanic risk assessment and monitoring activities of Canary Islands, is assigned to the National Geographic Institute (Instituto Geográfico Nacional - IGN), which is also in charge of transferring information to the Civil Protection authorities in the country. The IGN Volcano Monitoring System (VMS) includes permanent geophysical and geodetic stations, temporal stations and field campaigns. Nowadays, IGN is using Sentinel-1 data, applying tools and methodologies developed in the Safety project, in order to support the modelling and monitoring activities.
U-Geohaz, will improve the Safety results in order to evolve from mid-term mapping to a near-real time mapping and monitoring, and to support in this way the Early Warning activities. specifically, the procedures will be tested and validated over the islands La Palma, Tenerife, and el Hierro.
Rockfalls are the most frequent and damaging landslide type in the archipielago, in the past decade the Emergency Services from Gran Canaria and Tenerife Island accumulate more than 7000 rockfall events producing damages to communication networks. In this context, a set of tools to support an early warning system for rockfalls, which is relevant for the Canary Island CP, will be developed in U-Geohaz, starting from the knowledge acquired in the SAFETY and LAMPRE projects.
Valle d’Aosta (VDA) Region is located in the North-western Italian Alps, it is the smallest region of Italy covering an area of 3.200 km2. The morphology of VDA is characterized by highly variable topographic relief, ranging from 300 m a.s.l. to peaks higher than 4000 m a.s.l., with steep slopes mainly covered by forest, natural grassland, and rock outcrops with little or no vegetation. The region is crossed by a wide glacial east-west valley, and few tributary valleys, where few urban areas are localized. The regional climate, is characterized by wide range of temperatures and rainfall/snowfall, varying a lot from the mountainous zone to the bottom of the valleys. This strong variation, mainly the snow presence or absence, affects the DInSAR results, in terms of coherence and spatial coverage.
The slopes of VDA are characterized by high density of mass movements, which can be synthetically grouped in glaciers, rock glaciers, and landslides. Landslide process affects 18% of the VDA territory, varying in size and typology, from shallow landslides (soil slips, planar, and rotational sliding) to large slope instabilities (Cignetti et al., 2016). Specifically, Deep-seated Gravitational Slope Deformations (DsGSDs) affect at least 13.5% of the regional territory, for a total of 280 phenomena inventoried (Cignetti et al., 2016). DSGSDs are large to extremely large mass movements generally affecting the entire length of high-relief valley flanks, extending up to 200–300 m in depth, which frequently
extend beyond the slope (Crosta et al, 2019). Their evolution is controlled by the interaction of different factors: lithology, geology, climate weathering, seismicity, and deglaciation (Crosta et al, 2019). These phenomena generally present very slow–slow deformation rates, variable from a few millimetres per year to a maximum of a few centimetres per year in uncommon cases. The study of the activity state and evolution of these phenomena is very important because several villages have been built in or nearby.
Araña, V. and Ortiz, R (1991) The Canary Islands: Tectonics, magmatism, and geodynamic framework, in: Magmatism in Extensional Structural settings and the Phanerozoic African Plate, edited by: Kampunzu, A. and Lubala, R., Springer, New York, 209–249.
Carracedo, J.C., Pérez, F.J., Ancochea, E., Meco J., Hernán, F., Cubas C.R., Casillas, R., Rodriguez, E. and Ahijado, A. (2002) Cenozoic volcanism II: The Canary Islands. In: The Geology of Spain. Ed. Gibbons, W. and Moreno, T., Geological Society of London, 439-472.
Cignetti, M., Manconi, A., Manunta, M., Giordan, D., De Luca, C., Allasia, P., & Ardizzone, F. (2016). Taking advantage of the esa G-pod service to study ground deformation processes in high mountain areas: A valle d’aosta case study, northern italy. Remote Sensing, 8(10), 852. https://doi.org/10.3390/rs8100852
Crosta, G.B., Frattini, P., Agliardi, F. (2013) Deep seated gravitational slope deformations in the European Alps. Tectonophysics, 605, 13–33.
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