Some dangerous natural phenomena, like large rock avalanches and faults slipping during earthquakes, show a peculiar behaviour characterized by a very low friction. Many attempts have been advanced by scholars in the last decades in order to explain that behaviour, but none of them have been generally accepted by the international community. This study takes into consideration the effects of dynamic fragmentation on the mechanics of rock avalanches motion in order to explain the slip weakening shown by these phenomena at the sliding surface. Experiments have been conducted by means of a high pressure rheometer purposely built capable to apply a direct stress up to 4 MPa on a sample of rock granules. First results are promising toward an advance in understanding the motion mechanics of rock avalanches and the prediction of their runout possible reach.

Since the last decades of the last century, a high labour costs and exhausting of ground resources have caused the closure of many mines in Italy. According to Atti miniere 2009, 3000 mines were producing between 1870 and 2006 in Italy; at present time only about 20 mines are still in operation. Most of the abandoned mines may contain hazards to human life and environment. This article presents a case study of a abandoned mine in North Eastern Italy and the hazard induced by its tailings dams.

Erosion and landslides are have been identified as two of the major threats that affect European soils. In Italy vineyards cultivated on hill and mountain slopes are frequently affected by intense soil erosion processes and landslides, especially during extreme rainfall events. The management practices adopted in vine cultivation are strictly related with hydrological processes and land conservation in vine-growing areas. The disturbance of the soil profile and land leveling works during the vineyard plantation, the orientation of the vine-rows along the slope, tillage and maintenance of bare soil in the inter-rows affect strongly water infiltration and runoff formation and expose the soil to degradation processes, such as soil erosion, decrease of carbon content and compaction. Furthermore intense runoff and gully erosion processes in vineyards are often related to the occurrence of soil-slips and mud flows, as documented by historical data on landslides collected by IRPI. The first soil erosion measurements in vineyards from Piedmont were carried out for about 2 years by IMAMOTER and IRPI at beginning of '80s, in the Alto Monferrato vine production area. Long-term data have then been collected by IMAMOTER from field-scale vineyard plots within the Tenuta Cannona Vine and Wine Experimental Centre of Regione Piemonte, which is also located in Alto Monferrato. Since 2000, rainfall, runoff and soil erosion monitoring has been carried out under natural rainfall conditions on three parallel field plots (75 m long and 16,5 m wide, slope gradient about 15%) that are conducted with different inter-rows soil management techniques (conventional tillage, reduced tillage, controlled grass cover), with vines aligned along the slope. Experimental plots are part of a 16-hectars experimental vineyard, managed in according to conventional farming for wine production. The primary intent of the program was to evaluate the effects of agricultural management practices and tractor traffic on the hydrologic, soil erosion and land degradation processes in vineyards. The dataset include measurements for more than 200 runoff events and over 70 soil loss events; moreover, periodic measurements for soil physical and hydrological characteristics are included for the three plots. The analysis of data collected over more than a decade in the Cannona Experimental Site showed that the use of permanent grass cover in the inter-rows reduces runoff and especially soil losses at yearly and seasonal scale. The worst soil management was the reduced tillage , which produced the highest water and soil losses. The use of permanent grass cover in the inter-rows improved water infiltration and reduced runoff and especially soil losses, even if it was not very effective in the first three years of installation. The best performance of grass cover reducing runoff and soil erosion was shown during summer storms, while it was less effective during autumn, which is the season where extraordinary meteorological events have stroked Piedmont during last decades. The soil and water conservation in the vine-growing systems will be more and more relevant, taking in account climate changes that predict increase in rainfall intensity and erosivity. The monitoring activities at the Cannona Experimental Site are currently carried out and implemented in order to improve the understanding of the soil management effects on soil hydrology, erosion and landslides triggering in sloping vineyards. The results obtained from the Cannona long-term monitoring program could be useful in a multidisciplinary approach to investigate interactions among land use/ soil management and natural processes at different scales, raising up from hillslope to small basin scale and to address the adoption of adequate water and soil conservation practices.

Erosion and landslides have been identified as two of the major threats that affect European soils. In Italy vineyards cultivated on hill and mountain slopes are frequently affected by intense soil erosion processes and landslides, especially during extreme rainfall events. The management practices adopted in vine cultivation are strictly related with hydrological processes and land conservation in vine-growing areas. The disturbance of the soil profile and land leveling works during the vineyard plantation, the orientation of the vine-rows along the slope, tillage and maintenance of bare soil in the interrows affect strongly water infiltration and runoff formation and expose the soil to degradation processes, such as soil erosion, decrease of carbon content and compaction. Furthermore intense runoff and gully erosion processes in vineyards are often related to the occurrence of soil-slips and mud flows, as documented by historical data on landslides collected by IRPI. The first soil erosion measurements in vineyards from Piedmont were carried out for about 2 years by IMAMOTER and IRPI at beginning of '80s, in the Alto Monferrato vine production area. Long-term data have then been collected by IMAMOTER from field-scale vineyard plots within the Tenuta Cannona Vine and Wine Experimental Centre of Regione Piemonte, which is also located in Alto Monferrato. Since 2000, rainfall, runoff and soil erosion monitoring has been carried out under natural rainfall conditions on three parallel field plots (75 m long and 16.5 m wide, slope gradient about 15%) that are conducted with different inter-rows soil management techniques (conventional tillage, reduced tillage, controlled grass cover), with vines aligned along the slope. Experimental plots are part of a 16-hectars experimental vineyard, managed in according to conventional farming for wine production. The primary intent of the program was to evaluate the effects of agricultural management practices and tractor traffic on the hydrologic, soil erosion and land degradation processes in vineyards. The dataset include measurements for more than 200 runoff events and over 70 soil loss events; moreover, periodic measurements for soil physical and hydrological characteristics are included for the three plots. The analysis of data collected over more than a decade in the Cannona Experimental Site showed that the use of permanent grass cover in the inter-rows reduces runoff and especially soil losses at yearly and seasonal scale. The worst soil management was the reduced tillage, which produced the highest water and soil losses. The use of permanent grass cover in the inter-rows improved water infiltration and reduced runoff and especially soil losses, even if it was not very effective in the first three years of installation. The best performance of grass cover reducing runoff and soil erosion was shown during summer storms, while it was less effective during autumn, which is the season where extraordinary meteorological events have stroked Piedmont during last decades. The soil and water conservation in the vinegrowing systems will be more and more relevant, taking in account climate changes that predict increase in rainfall intensity and erosivity. The monitoring activities at the Cannona Experimental Site are currently carried out and implemented in order to improve the understanding of the soil management effects on soil hydrology, erosion and landslides triggering in sloping vineyards. The results obtained from the Cannona long-term monitoring program could be useful in a multidisciplinary approach to investigate interactions among land use/ soil management and natural processes at different scales, rising up from hillslope to small basin scale and to address the adoption of adequate water and soil conservation practices.

In November and December 2013, the Marche region (Central Italy) was hit by three severe, but not rare, meteorological events. The maximum value of the three days cumulative rainfall (499 mm) was recorded at the rain gauge of Pintura di Bolognola. The intense rainfall caused floods along the rivers and triggered numerous landslides, mostly located in the hilly and mountainous terrain of the region. The territory is crossed by a large number of roads connecting small rural settlements. After the events, the Regional Civil Protection Office requested to the Research Institute for the geo-hydrological Protection (IRPI-CNR) a technical support to evaluate the hazard condition for different sites affected by landslides. For an area of approximately 200 km2, in the Municipalities of Acquasanta Terme and Roccafluvione, field surveys were carried out to identify the rainfall-induced landslides and to produce an event inventory map. More than 1,500 slope failures were mapped including earth flows, slide-earth flows, slides, rock-falls and complex slides. Field surveys were focused also to estimate qualitatively damages along the roads. Roads were classified in two classes_ the main roads under the State responsibility and the secondary roads under the Municipality responsibility. The different types of damage were classified in three classes_ i) aesthetic (minor), where the road functionality was not compromised; ii) functional (medium), where the functionality was compromised and iii) structural (severe) where roads are severely or completely damaged. Immediately after the event, the technicians of the Municipalities of Acquasanta Terme and Roccafluvione spent major efforts to partially restore the functionality of the secondary roads in order to guarantee the primary human needs. In the following ten days, they compiled a list of interventions, associated with the relative direct costs, aimed to the total restoration of the roads functionality. In collaboration with the technicians, we compared the estimate of the damages along the roads with the cost evaluation provided by the local authorities. The comparison allowed us to quantify the impact of the landslide events along the transportation infrastructures and to quantify the total direct cost for the secondary roads where the information was available.

Statistical based landslide susceptibility models are widely used in medium to regional scale assessments. The two main inputs in these models are the landslide inventory of past events and the landslide caustative factor maps. In this study we assessed how the performance and prediction capability of the Weights-of-Evidence (WofE) susceptibility model is affected by the way we represent landslides in the pixel format, considering the entire polygon or only the landslide centroid. Influence of pixel density representing the landslide polygon was also taken into account. The second part of the research concidered the effect of the landslide model training and prediction sample sizes on the performance and prediction rates of the WofE model. Two case study areas were chosen to apply the representation and sampling tests_ (1) the Fella River Basin (Eastern Italian Alps) containing debris flows and (2) the four times larger Buzau County (Romanian Carpathians) containing shallow landslides. Both areas are very different in terms of size, landslide types and geo-environmental factors, and were chosen in order to determine the applicability and flexibility of our analysis. Our results indicate that there is only a minor increase in performance and prediction when increasing the number of pixels to represent the entire landslide polygon. As the number of pixels increased from a single centroid to all pixels within the polygon, we found that the relative increase in pixels was similar within all classes (e.g. grass-land, forest, bare rock) of each thematic factor map like land-use or litholo gy. This indicated that the landslides have a similar size across the entire study area and is one of the causes of the lack of significant increase in model performance. The similari ty in performance and prediction rates for different landslide representation tests was in contrast to their respective susceptibility maps, which did show significant differences among each-other. This requires further analysis in future studies to determine which susceptibility map should be chosen for decision making. As for the sample size analysis, we have found that using 10 to 20% of all landslides to train the WofE model in both case studies is sufficient to predict the remaining 80 to 90% of the landslides. Modeling with more than 20% of the landslides causes a "plateau effect" in the performance and prediction rates. This indicate s that only a small percentage of all the landslides in an inventory are needed for good prediction results, making it also unnecessary to map every landslide in the area for a suffici ent performing landslide susceptibility analysis.