Hypsometric Analysis of Headwater Rock Basins in the Dolomites (Eastern Alps) Using High‐Resolution Topography

Hypsometric curves and integrals are effective tools for rapid quantitative assessments of topography. High‐resolution digital terrain models derived from airborne LiDAR data have been analysed to study the hypsometry of small headwater rock basins (drainage areas up to 0.13 km²) in three study areas in the Dolomites (Eastern Alps) that have similar lithologies and climatic conditions. Hypsometric curves in the studied rocky headwaters display a variety of shapes and present remarkable differences between neighbouring basins. Hypsometric integrals show generally high values in the three study areas (>0.42, mean values between 0.51 and 0.65). The extent of the scree slopes located at the foot of rock basins in the three study areas is larger in the area with lower hypsometric integrals and indicates consistency between the development of basin erosion, which is shown by the hypsometric integral, and debris yield, represented by the extent of scree slope. No clear relations were observed between the hypsometric integrals and basin area and shape. When extending the analysis to larger basins, which encompass rocky headwaters and downslope soil‐mantled slopes, a negative correlation is found between the hypsometric integral and catchment area, suggesting that the scale independency of the hypsometric integral occurs essentially in headwater rock basins. Geomorphometric indices (residual relief and surface roughness) have contributed to interpreting the variability of surface morphology, which is related to the geo‐structural complexity of the catchments.     

Chronicle of the 1865, NE flank eruption of Mt. Etna and geomorphologic survey of the Mts. Sartorius area

The row of pyroclastic cones named Mts. Sartorius, outcropping on the NE flank of Etna, formed in 1865 during a lateral eruption that lasted about 6 months. The event was eye witnessed and described by numerous scientists and reporters. In this work, we use their observations to reconstruct the eruption chronology and scenario, and carry out a detailed geomorphologic survey to identify the eruptive features and pyroclastic deposits. The 1865 eruption began on 29 January along a segment of the main system of fractures oriented ENE–WSW, radial to the central conduit. After 30 January, a secondary system of fractures trending NNW–SSE was simultaneously active. The six larger Mts. Sartorius cones developed since 3 February along the lower extension of the radial system. They are markedly asymmetric due to the persistent winds blowing at the time and to the pre-existing topography formed on underlying deposits, previously unreported, that we have recognized. Now, about 150 years after the eruption, most of the eruptive vents and fractures are no longer observable in the field, being mostly hidden by products of subsequent phases of the eruption and by younger epiclastic deposits.     

List of papers from other journals

List of papers from other journals     

Guidelines for the good practice of surface wave analysis: a product of the InterPACIFIC project

Surface wave methods gained in the past decades a primary role in many seismic projects. Specifically, they are often used to retrieve a 1D shear wave velocity model or to estimate the V_S,30 at a site. The complexity of the interpretation process and the variety of possible approaches to surface wave analysis make it very hard to set a fixed standard to assure quality and reliability of the results. The present guidelines provide practical information on the acquisition and analysis of surface wave data by giving some basic principles and specific suggestions related to the most common situations. They are primarily targeted to non-expert users approaching surface wave testing, but can be useful to specialists in the field as a general reference. The guidelines are based on the experience gained within the InterPACIFIC project and on the expertise of the participants in acquisition and analysis of surface wave data.     

The fate of Lake Baikal: how climate change may alter deep ventilation in the largest lake on Earth

Lake Baikal is the oldest, deepest, and most voluminous freshwater lake on Earth. Despite its enormous depth, episodically (almost twice a year) large amounts of surface, cold, and oxygenated water sink until the bottom of the lake due to thermobaric instability, with consequent effects on the ecology of the whole lake. A minimal one-dimensional model is used to investigate how changes in the main external forcing (i.e., wind and lake surface temperature) may affect this deep ventilation mechanism. The effect of climate change is evaluated considering the IPCC RCP8.5 and some idealized scenarios and is quantified by (i) estimating the mean annual downwelling volume and temperature and (ii) analyzing vertical temperature and dissolved oxygen profiles. The results suggest that the strongest impact is produced by alterations of wind forcing, while deep ventilation is resistant to rising lake surface temperature. In fact, the seasons when deep ventilation can occur can be shifted in time by lake warming, but not dramatically modified in their duration. Overall, the results show that Lake Baikal is sensible to climate change, to an extent that the ecosystem and water quality of this unique lacustrine system may undergo profound disturbances.     

A procedure to estimate the seismic hazard in an urban area: an application to Acireale (Eastern Sicily)

A “standard procedure” to characterize the seismic hazard of a given area was proposed. It is based on a multidisciplinary approach implying: (1) the knowledge of the seismic history of the area; (2) detailed geological surveys; (3)seismic noise measurements; (4) simulations of earthquake scenarios. The downtown of Acireale, a typical baroque town located on Eastern Sicily, was chosen as the “test area”. A catalog of the local seismogenic faults (able to generate earthquakes in historical times) has been compiled, as well as a seismic catalog for the effects of both local and regional earthquakes. The analysis of both catalogs allowed us to make the following conclusions: (1) the most important seismogenic faults affecting the Acireale municipality do not affect the downtown, while the related local earthquakes attenuate their energy (and intensity) in short (few km) distances; (2) the highest seismic intensity (degree X) experienced in Acireale downtown was caused by the 1693 regional earthquake; (3) over the last 140 years, the downtown has experienced the highest intensity value of VII only once, while six times the intensity was VI. On the whole, this implies a moderate seismic hazard. The estimation of the seismic hazard has been also approached by the experimental method of recording seismic noise. Measurements have been performed at seven different sites, where drills gave detailed information on the shallow subsurface geology to obtain HV (horizontal/vertical) spectral ratios. On the whole, the highest site amplification factor was moderate (about 7). A further investigation based on synthetic seismograms (and spectra) produced by simulating two given earthquake scenarios was also performed. The two scenarios are, respectively, representative of the largest expected earthquake in the area (the 1693 shock) and of a moderate (magnitude ca. 5.5) local earthquake (as the 1818 one). Moderate to strong locally expected accelerations were evidenced.     

A Geostatistical Simulation Approach to a Pollution Case in Northeastern Italy

The study zone is located in the city of Padova (the Veneto region, NE Italy). The industrial activities present in this area since 1950 have produced very high concentrations of Pb, Zn, Cu, Pcb and oils until a depth of 7 m. The unsaturated and the saturated zones are both polluted. Because of the abundance of Pb values it was decided to analyze the lead distribution in the studied zone. In many studies of the polluted sites, the geometry of the investigated volume is highly anisotropic. Generally we have an extension of some hectares in the horizontal plane and of a few meters in depth. It is likely that different horizontal spatial continuity structures in pollution distribution are found at different depths both for the layered nature of the medium and for the transition between unsaturated and saturated conditions. In such conditions the decision to divide a 3D problem into 1D and 2D problems can be useful. Initially the studied volume was divided into seven layers up to 5 m in depth; the study was then approached in two phases. First, the Pb values in the vertical direction were analyzed, considering a derive along z, and estimating the values using the Kriging with Trend (KT) method. Thus it was possible to increase the data in the z direction, especially in the deeper layers. Second, 500 realizations of the Pb distribution for each of the seven layers were simulated using the simulated annealing procedure. Finally, results were presented and discussed for each layer in terms of median and probability maps.     

GIS tools for preliminary debris-flow assessment at regional scale

The assessment of the areas endangered by debris flows is a major issue in the context of mountain watershed management. Depending on the scale of analysis, different methods are required for the assessment of the areas exposed to debris flows. While 2-D numerical models are advised for detailed mapping of inundation areas on individual alluvial fans, preliminary recognition of hazard areas at the regional scale can be adequately performed by less data-demanding methods, which enable priority ranking of channels and alluvial fans at risk by debris flows. This contribution focuses on a simple and fast procedure that has been implemented for regional-scale identification of debris-flow prone channels and prioritization of the related alluvial fans. The methodology is based on the analysis of morphometric parameters derived from Digital Elevation Models (DEMs). Potential initiation sites of debris flows are identified as the DEM cells that exceed a threshold of slope-dependent contributing area. Channel reaches corresponding to debris flows propagation, deceleration and stopping conditions are derived from thresholds of local slope. An analysis of longitudinal profiles is used for the computation of the runout distance of debris flows. Information on erosion-resistant bedrock channels and sediment availability surveyed in the field are taken into account in the applications. A set of software tools was developed and made available (https://github.com/HydrogeomorphologyTools) to facilitate the application of the procedure. This approach, which has been extensively validated by means of field checks, has been extensively applied in the eastern Italian Alps. This contribution discusses potential and limitations of the method in the frame of the management of small mountain watersheds.     

A first order evaluation of the capacity of a healthcare network under emergency

Immediately after an earthquake a healthcare system within a city, comprising several hospitals, endures an extraordinary demand. This paper proposes a new methodology to estimate whether the hospital network has enough capacity to withstand the emergency caused by an earthquake. The ability of healthcare facilities and to provide a broad spectrum of emergency services immediately after a seismic event is assessed through a metamodel that assumes waiting time as main response parameter to assess the hospital network performance. The First Aid network of San Francisco subjected to a 7.2 Mw magnitude earthquake has been used as case study. The total number of injuries and their distributions among the six major San Francisco's Emergency Departments have been assessed and compared with their capacity that has been determined using a survey conducted by the medical staff of the hospitals. The numerical results have shown that three of the six considered San Francisco's hospitals cannot provide emergency services to the estimated injured. Two alternatives have been proposed to improve the performance of the network. The first one redistributes existing resources while the second one considers additional resources by designing a new Emergency Department.