Considered phenomena Sample Clauses

Considered phenomena. The Xxxxxxxx landslide area is located in Assisi, Italy. The town of Assisi extends along the NE sector of the mountain ridge represented by the Monte Subasio, a distinct physiographical feature in central Umbria, and is bounded to the SW by the ample Xxxxx Umbra plain (figure 1A). Sedimentary rocks crop out in the area. Layered and massive limestone, marl, and clay pertaining to the Umbria-Marche stratigraphic sequence, Lias to Eocene in age, are overlaid by lake deposits, lower Pliocene to Quaternary in age, and by fluvial deposits, recent in age.
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Considered phenomena. The study area (Monti Nebrodi and Giampilieri) is located along the north eastern part of Sicily (Southern Italy). In the period from October 2009 to February 2010, the area was highly affected by several landslide events that caused intense damages and casualties. The landslide events continue till today as testified by the event occurred during March 2011 in San Fratello where 12 people were evacuated. The Monti Nebrodi ridge is 70 km long with ENE-WSW direction and is part of the Sicilian Apennines. The altitude of the area spans from the sea level to 1847 m (Xxxxx Xxxx). Intense and exceptional rainfall event was the main factor that, combined with the steep slopes, triggered several slope movements along the Monti Nebrodi. In particular debris flow, rotational and translational slides, rock falls and shallow and deep-seated landslides occur. Giampilieri is located on the eastern coast of Sicily, in the Peloritani Mountain Belt which represents a segment of the Apennine-Maghrebide Orogen. The geomorphology of the area is strongly influenced by the geo-structural conditions, by the crystalline competence of the outcropping rock (mainly medium grade metamorphic rocks) and by the recent tectonic activity. The coastal landscape is typical of the recently uplifted areas: steep slopes, narrow valleys and high relief energy are the main geomorphologic feature. The morphometric characteristics of the river basins, represented by a watercourse network having regular and parallel paths, are influenced by the short distance separating the watershed from the coast. River catchments have a reduced widening with a significant transport of solid materials; incisions are short and deeply entrenched into V-shaped valleys, especially in the mountainous sector. Several small alluvial plains, formed where riverbeds become over-flooded, characterise the coastal area. The presence of the so-called "fiumare", straight, steep course, gravel-bed river draining mountain areas is typical of Mediterranean climate region. Their flow varies seasonally and their regime is torrential with catastrophic transport of solid materials following heavy rainfall, causing severe damage if flooding occurs close to populated centres. In this area the main type of landslides that have occurred can be classified as debris flow and debris avalanches. More than 600 landslides in a day were triggered by exceptionally intense and localized rainfalls.
Considered phenomena. The Hungarian lowland is located to the south and to the west of the Carpathian mountain range and bounded to the south-east by the Transylvanian Alps. Landscape is characterized by plains, rolling hills and low mountains. The area is drained by tributaries of the Tisza River, which drains into the Danube. Climate is continental to sub-continental, with a mean annual precipitation less than 1000 mm. In the area sedimentary rocks (sandstone and conglomerates), crystalline schist with limestone, and volcanic material crop out. A Loess cover is present in the area. Due to local morphological and geological settings, mass movements of different types are common, and cause extensive damage to buildings and the infrastructure. Three landslide sites have been preliminarily singled out:
Considered phenomena. The study area is located to the north of the Carpathian mountain range, in the central part of the Upper Silesian Coal Basin (USCB), in southern Poland. Coal mining activity in the USCB has been conducted since the 17th century. In 1979 the largest amount of coal 200x10 Mg/year was mined. At present there are 30 active coal mines in the USCB. Total exploitation of coal is estimated at 70x106 Mg/year. In the study area, hazardous ground deformations are caused primarily by the extensive and longwall mining operations, chiefly in the vicinities of the cities of Katowice, Zabrze and Xxxx Xxxxxx. The subsidence in Upper Silesia commonly reaches velocities of a few centimeters per month but there are many areas with subsidence of one centimeter daily. Exploitation of coal deposits, conducted in the USCB for over 200 years, has created a complicated state of stress and deformation, which is the cause of dynamic phenomena manifested in the form of rock mass shock. Systematic seismic observations have been here for about 60 years. Currently, Central Mining Institute conducts and develops catalogues "of strong mining tremors" on the basis of data sent by the Upper Silesian Regional seismic network (GRSS) and mining seismological network (KSS).
Considered phenomena. The island of Majorca has a variety of different geomorphological domains, most prominently the Tramuntana Range (1,100 km2) in the northwestern part of the island (Fig. 1). The steep topography of this chain, which is linked to its geological complexity and Mediterranean climate, determines intense slope dynamics (Xxxxxx, 2002; Xxxxxx and Xxxxxx, 2005). Practically all the slope movements recorded on Majorca have taken place in the Tramuntana Range. The variety of lithologies cropping out in this mountain chain determines a wide range of slope movements. Landslides and earth flows are frequent phenomena, primarily affecting soft sediments from the Late Triassic (Xxxxxx), made up of clays with gypsum, as well as an entire series of loamy materials from the Palaeogene and Neogene that occasionally outcrop along the mountain range. The historical compilation of the slope movements on the island (Xxxxxx 2002, 2006), as well as the record of those that have occurred more recently, reveal that all processes have taken place after short intense and/or continuous rainfall. During the hydrological years 2008 to 2010, Xxxxxxx experienced one of the coldest and wettest xxxxxxx in living memory. Not only did the accumulated rainfall show twice the average recorded values, this period also witnessed the highest rates of intense rainfall (up to 296 mm/24
Considered phenomena. The St. Moritz - Engadine valley area is close to the Piz Bernina in central Alps. In the area Middle and Upper Triassic platform carbonates, mainly dolomites, crop out, overlain by hemipelagic limestone-marl-alternations of Early Jurassic to Early Cretaceous age. The Mesozoic sediments are partly still in contact with the basement, but have also been partly sheared off. Landslides, rock falls and permafrost activities are widespread. Due to climate change, these hazards should be integrated into an inventory and hazard assessment. Satellite and terrestrial SAR interferometry would be an important value added information.
Considered phenomena. In the Mattervalley, going up from Visp in the bottom of the Rhonevalley to Zermatt, mainly metamorphic rocks (schists and gniesses) crop out. In the valley there are numerous unstable slopes, including some densely populated regions prone to landslides. Many landslides, rockslides, and rock falls are still active and there are high annually costs for the mitigation and countermeasures. Several large landslides are monitored in the study area, allowing an integration of the InSAR technique for hazard assessment. Numerous active rock glaciers (related to the presence of permafrost in the area) common above 2200 to 2500 m a.s.l., are recognized in the Mattervalley, showing an increasing velocity since the 1980s, in response to a significant permafrost warming. Most active rockglaciers are well detectable with ERS, ENVISAT, JERS, ALOS and TerraSAR-X interferometry at monthly time lapse, whereas the slowest are only visible at yearly interval.
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Considered phenomena. Landslide hazard in the Xxxxxxx Province (North-eastern Sicily, Italy) is mainly associated with instability phenomena in the Monti Nebrodi ridge, that is a 70 km long ridge with ENE-WSW direction and it is part of the Sicilian Apennines. Recent landslides affected the town of San Fratello, located to the west of the city of Xxxxxxx. The history of San Fratello is marked by historical landslide events such as the January 11th 1922, a landslide that caused hundreds of deaths in the town and about 10,000 people were evacuated (Xxxxxxxx, 2000). On 13th and 14th February 2010, the east side of San Fratello was affected by a landslide of considerable size (about 1 km2, according to preliminary estimates by the Regional Department of Civil Defense, Region Sicily (DRPC)). In the geographic position of San Fratello and a detail of an orthophoto of the studied area, with the first contouring of the landslide, are shown. The geomorphology of the area, with frequent slope breaks and many erosion forms, makes the area prone to these types of landslides, especially on lithologies characterized by poor mechanical properties, such as those outcropping in the zone. Intense and exceptional rainfall event was the main factor that, combined with the steep slopes, Figure 3 - Geographic location of San Fratello and a detail of an orthophoto of the studied area, with the first contouring of the landslide (in red). 13 triggered several slope movements along the Monti Nebrodi. After the last event (February 13th, 14th 2010), a detailed study of the geology of the area has been conducted; it revealed the presence of a silt-clay overlay, with a thickness of about 10 m, above the clayey unit called Argille Scagliose Superiori and, locally, the presence of alternating sandstones and clays levels, belonging to the Xxxxxxxx Flysch and the Xxxxx Xxxx Flysch. Moreover, throughout the inhabited area, there is an aquifer, with depth between 0.5 and 2.5 meters.
Considered phenomena. The study area is located in the upper part of the Xxxxxxx River valley in the Central Spanish Pyrenees (Sallent xx Xxxxxxx, Xxxxxx) close to the Formigal ski resort. This is a structurally complex area, outcrops of Paleozoic material of Gavarnie mantle were affected by the Hercynian folding phases and the alpine tectonics. Pyrenean deglaciation and widespread structural relaxation shaped the landscape triggering complex landslides that have been previously described and mapped by various authors (Xxxxx et al. 1985, Xxxxxx-Xxxx et al. 2004). We focus our work on two of these landslides developed on the southwest-facing hillside of Petrasos Peak: the “Portalet landslide” and “Xxxxxxx landslide" (landslides 2 and 5 in Fig. 11). These landslides are rotational slide earth flows, 30 to 50 meters thick. The mobilized materials involve sands and gravels found within a clayey matrix with sandstone levels, greywackes and shales. A subsequent third earth flow can be recognized in the north part of the Portalet landslide (landslide 1 in Fig. 11). Nowadays, rock falls and avalanches are still occurring in the main scarps. Recent small landslides triggered by river erosion can also be found on the toe of the main landslides.
Considered phenomena. The Mattervalley in the Swiss Alps starts from Visp at the bottom of the Rhonevalley up to the famous station of Zermatt (Fig. 15). In this valley there are numerous instable slopes, including some densely populated regions prone to landslides. There are also many installations for touristic purposes in the unstable slopes, sometimes located in the permafrost areas. Many landslides, rockslides, and rockfalls are still active and there are high annually costs for the mitigation and countermeasures. The damage concerns inhabited areas, touristic installations and many roads. For the Mattervalley a landslide monitoring is not available, but several of the large landslides are known and the geological documents will allow an integration of the radar interferometric techniques for hazard assessment. Due to the high costs related to landslide activity and to the difficulties in the detection of the active, slow or dormant portions of the landslide, the use of a radar interferometric approach can positively impact on the current practices used by the local authorities to carry out the hazard mitigation activities.
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