Airborne remote sensing systems are increasingly used in engineering geology and geomorphology for studying and monitoring natural hazardous scenarios and events. In this study, we used two remote sensing monitoring techniques, i.e., light detection and ranging (LiDAR) and unmanned aerial vehicles (UAV) to analyze the kinematic evolution of the Montescaglioso landslide (Basilicata, Southern Italy), a large rain-triggered landslide that occurred in December 2013. By comparing pre- and post-event LiDAR and UAV DEMs and UAV orthomosaics, we delineated landslide morphological features and measured horizontal displacements and elevation change differences within landslide body. Analysis of two subsequent post-events digital terrain models (DTMs) also allowed the evaluation of the evolutionary behavior of the slope instability, highlighting no signs of reactivation. The UAV-derived digital surface models (DSMs) were found consistent with the LiDAR-DTMs, but their use was in addition highlighted as highly effective to support geomorphic interpretations and complement LiDAR and field-based data acquisitions. This study shows the effectiveness of combining the two UAV-LiDAR methodologies to evaluate geomorphological features indicative of the failure mechanism and to interpret the evolutionary behavior of the instability process

In this paper, a study aimed to assess the landslide susceptibility at a regional scale for the wide provincial territory of Matera (Basilicata region, southern Italy) and the relative risk along the main road corridors distributed in this area is presented. A heuristic-bivariate statistical predictive model was performed to assess and map the landslide susceptibility in the study area by using a polynomial function of eight predisposing factors, weighted according to their influence on the instability process. The resulting susceptibility map was successively used for assessing the landslide risk along the provincial road network. The importance of these roads, representing the main network connecting the urban centres, derives from the absence of an efficient integrated transportation system through the entire regional territory. The landslide risk was evaluated through a matricial approach, which has allowed to define the risk levels (low, medium and high) along road stretches by overlapping the consequences and hazard maps, by combining their corresponding classes in a matrix and by associating to each combination a risk level. The resulting landslide risk map provides support information for decision-making and for identifying the priorities for the design of appropriate mitigation plans.

The increasing number of wildfires in southern Europe is making our ecosystem more vulnerable to water erosion; i.e., the loss of vegetation and subsequent runoff increase cause a shift in large quantities of sediment. Fire severity has been recognized as one of the most important parameters controlling the magnitude of post-fire soil erosion. In this paper, we adopted a combination of methods to easily assess post-fire erosion and prevent potential risk in subsequent rain events. The model presented is structured into three modules that were implemented in a GIS environment. The first module estimates fire severity with the Monitoring Trends in Burn Severity (MTBS) method; the second estimates runoff with rainfall depth–duration curves and the Soil Conservation Service Curve Number (SCS-CN) method; and the third estimates pre- and post-fire soil erosion. In addition, two post-fire scenarios were analyzed to assess the influence of fire severity on soil erosion: the former based on the Normalized Difference Vegetation Index (NDVI) and the latter on the Relative differenced Normalized Burn Index (RdNBR). The results obtained in both scenarios are quite similar and demonstrate that transitional areas, such as rangelands and rangelands with bush, are the most vulnerable because they show a significant increase in erosion following a fire event. The study findings are of secondary importance to the combined approach devised because the focal point of the study is to create the basis for a future tool to facilitate decision making in landscape management.

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Studies dating almost a century relate clay properties with the structure of the diffuse double layer (DDL), where the charged surfaces of clay crystal behave like an electric capacitor, whose dielectric is the interstitial fluid. The intensity of the inner electric field relates to the concentration and type of ions in the DDL. Other important implications of the model are less stressed: this part of the clay soil system, energetically speaking, is conservative. External contribution of energy, work of overburden or sun driven capillarity and long exposure to border low salinity waters can modify the concentration of pore-waters, thus affecting the DDL geometry, with electric field and energy storage variations. The study of clay soils coming from various natural geomorphological and hydrogeological contexts, determining a different salinity of interacting groundwater, shows how the clay interaction with freely circulating waters at the boundaries produces alterations in the native pore water salinity, and, at the nano-scale, variations of electric field and stored energy from external work. The swelling and the shrinkage of clay soil with their volumetric and geotechnical implications should be regarded as variations of the electrostatic and mechanical energy of the system. The study is based on tests on natural clay soil samples coming from a formation of stiff blue clays, widespread in southern Italy. Geotechnical identification and oedometer tests have been performed, and pore waters squeezed out from the specimens have been analyzed. Tested samples have similar grain size, clay fraction and plasticity; sorted according to the classified geomorphological/hydrogeological contexts, they highlight good correlations among dry density, mechanical work performed in selected stages of the oedometric test, swelling and non-swelling behaviour, and electrical conductivity of the squeezed pore waters. The work performed for swelling and non-swelling samples shows well-defined differences; this endorse the relevance of pore-water salinity in determining the volumetric state of clay soils under overburden and specific hydrogeological border conditions, which together define a specific energetic state.