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Background: Rockfalls pose a serious threat along the main road network, representing a major hazard in mountainous territory and causing damage and victims. Currently, susceptibility mapping represents a starting point to identify areas more susceptible to rockfall occurrence, a key approach in land use planning and risk management. Despite the extensive use of these maps by decision makers and administrators, the usability of such maps over time and their reliability represent a poorly discussed and examined feature. Methods: Here, we proposed a-posteriori analysis of a three-year-old rockfall susceptibility map, generated along the main road network of the Aosta Valley, an alpine region of north-western Italy. To verify map consistency over time, we implemented a dual-analysis in GIS-environment and by text mining, to respectively analyse the geocoded data and textual information derivable from the regional landslide inventory. The first one allowed us to extract rockfall events occurred after the susceptibility map generation. By this way, we operated to spatially and temporally verify the map consistency. Jointly, the textual information reported in the Event Description Form, linked to each geocoded event, are being exploited. This allowed us to derive relevant information about occurred damage and their degree, presence of protective measures or secondary roads, i.e. involvement of, farm or forestry, road. Results: The implemented approach allowed us to prove the quality of the previous map in terms of reliability, robustness and degree of fitting respect to the succession of rockfall occurrence over time. After only three years as many as 198 rockfall events have been occurred and collected since the map was generated. Particularly, 80% of rockfall fit with "high" and "very high" susceptibility classes, and pointed out large involvement of main roads in rockfall occurrence, representing the most affected target with damage to road pavement and vehicles, as well as a relevant involvement of existing rockfall barriers and of the dense network of forestry roads and footpaths that characterize this alpine region. Results: The proposed approach representing a starting point in landslide susceptibility map verification and usability as valid instrument for a reliable land planning. [ABSTRACT FROM AUTHOR]

Many studies deal with the correlation between landslide velocity and damage degree of buildings or infrastructure. For shallow or moderate depth, slow landslides such as complex, slow flow or roto-translation type are well studied by InSAR or other ground-based instruments to retrieve a matrix correlation of velocity damage. However, few of them investigate the effects of deep-seated gravitational slope deformation (DsGSD) displacement. These phenomena usually have a very deep sliding surface, covering a vast area with constant velocity. This study investigates the building damage, mapped with a detailed field survey, correlated with one of the massive DsGSD of the Alps (Sauze d'Oulx DsGSD, NW Italy) affecting several villages. We used multi-temporal InSAR data and ground-based monitoring to obtain 26 years of displacement time series. The results show a complicated correlation, in which several factors influence the degree of building damage, such as the material of the building, their state of maintenance, the position on DsGSD, the depth of movement, the secondary process or the velocity range variability. A simple correlation with velocity is not exhaustive: the central part of DsGSD shows a higher velocity rate (up to 30 mm/yr), but with limited damage; while at the toe boundary of deformation, slow rate of movement produces more severe damage. These findings show that several in-depth studies should integrate velocity data from monitoring to assess the coexistence of these huge complex phenomena and define their impact on anthropic structures before making a risk assessment and a suitable land use planning of mountainous territory. [ABSTRACT FROM AUTHOR]

Rockfalls are a major hazard in mountain areas. They can endanger human settlements and infrastructures, and, every year, cause multiple damage and victims. An investigation of those areas more susceptible to rockfall represents a key approach to improve the analysis and management of rockfall impact and consequences. The proposed procedure involves the study of occurred rockfall databases and thematic maps to compute a susceptibility map, by the employment of Analytical Hierarchic Process. The computation is focused on the road network of Aosta Valley Region (northwestern Italy) and its proximity. The model results highlight the importance of morphometric factors on the investigated phenomena. The outcomes of the analysis were also validated by comparing rockfall databases with the receiver operating characteristic curve, in order to confirm their reliability. The results of the procedure are a starting point for a detailed planning action in order to manage the hazard related to these phenomena. [ABSTRACT FROM AUTHOR]

Landslide inventories provide the knowledge basis for many geomorphological applications and also planning and emergency management. Detailed landslide inventories should also be prepared where pre-existing inventories are available, as knowledge updates. In this paper, we present a new geomorphological landslide inventory for an area of the High Agri Valley, Southern Italian Apennines. The map was prepared through systematic interpretation of historical aerial photographs testing extensive use of anaglyph glasses in StereoPhoto Maker freeware. A total of 2124 landslides were classified based on the type of movement, estimated depth, estimated relative age and three levels of uncertainty, providing landslide attributes and map constraints useful for land planning and hazard studies. The map also documents the relationships between landslides and fluvial landforms of different generations, recording important information to investigate the geomorphological evolution of the area further. We expect that landslide mapping in similar environments will benefit from the workflow here presented. [ABSTRACT FROM AUTHOR]

In the autumn of 2014, a series of rainfall events affected several sectors of the Liguria region, triggering many shallow landslides and causing three casualties and severe structural damages. The most intensely unstable area covered 385 km2, in which more than 1600 landslides have been identified. After these events, an airborne Light Detection and Ranging survey was carried out. The survey yielded a high-resolution digital terrain model (DTM) and aerial images that provided a means of identifying and mapping all the occurred landslides. The distribution analysis of slope instabilities highlighted the link with various human activities. In fact, the majority of the detected landslides occurred in man-modified areas. Geospatial and statistical analyses provided the identification of three main anthropic factors: terraces, their level of maintenance and road network. Moreover, they quantified their role in landslide triggering. These factors were not analysed as separate elements, but as a continuous process, overlapping in time, in man-made influence on landscape. The identification of such factors is a key element for a correct behaviour characterization of this landscape towards extreme flash floods events. [ABSTRACT FROM AUTHOR]

Snow gliding, though a slow process, should be considered as important as the faster snow avalanche flows, as it can similarly produce severe damage to buildings and infrastructure. Snow gliding depends on snowpack properties, land cover and terrain parameters. Among these driving factors, in this work, we focus on stationary factors, that is, those that are considered features related to terrain and land cover, in particular those that could be derived from a Digital Elevation Model or land use/cover maps: slope angle, aspect, roughness and land cover. We propose a geographical information system-based procedure to create a snow gliding susceptibility index and to produce a related snow gliding susceptibility map. We tested this procedure in the Aosta Valley (NW Italian Alps), where the Monterosa Ski resort is located. The map covers an area of about 338 km2at a scale of 1:50,000. The proposed procedure is seen as a valuable tool to help safety personnel at ski resorts as well as in other scenarios (e.g. road management) in the identification of areas most prone to snow gliding. [ABSTRACT FROM AUTHOR]

Soil erosion in mountainous regions is a key issue in land use planning, and this is particularly true in the Alps where intense anthropogenic influences at low elevations and abandonment in higher regions often coexist to affect soils. Natural hazard and risk assessment are essential given the density of settlements and associated facilities. Soil loss due to water erosion is very common and is becoming more frequent as a consequence of climate change which affects precipitation regimes, frequency of extreme meteorological events, snow melt and vegetation. In this study, we describe the production of a map showing susceptibility to soil erosion in the Aosta Valley (northwest Italian Alps). Most research on slope instability has focused on rock failures, but we investigated upper soil horizons by analysing chemical and physical properties, which could contribute to slope instability. The steps involved in creating the map are explained, and these involved GIS overlay, sampling, soil description, selection of relevant chemical and physical indicators of soil susceptibility to erosion, and overall erosion susceptibility assessment. The resultant indicator values correspond well with field observations to thus validate the methodology and demonstrate its usefulness in land use planning and management in Alpine areas. [ABSTRACT FROM AUTHOR]

Mountain vineyards are a valuable resource for high-quality wine production and landscape conservation. A suitability map (1: 50,000) for mountain vineyard cultivation was created for a study area located in Aosta Valley (NW Italy). We considered the following environmental variables that are known to influence wine production: slope, aspect, altitude and soil, producing a suitability map that allows the identification of areas that can be considered practical for sustainable mountain viticulture. [ABSTRACT FROM AUTHOR]