Landslide Activity Maps for Landslide Hazard Evaluation: Three Case Studies from Southern Italy   总被引：7，自引：0，他引：7  

Parise  M.  Wasowski  J. 《Natural Hazards》1999,20(2-3):159-183

This paper focuses on the application of landslideactivity maps for evaluating the mass movementhazard in selected areas of the Southern Apenninesof Italy: Bisaccia, Calitri, and Buoninventre. Theavailability of multi-year aerial photo coveragehelped to assess the morphological changes whichoccurred in the last 40 years. This information,integrated with historical data on slope instabilityand field checks, were used to produce landslideactivity maps. These maps represent a short-cut inthe assessment of mass movement hazard, because theyfocus on the effects of slope instability ratherthan on the causative conditions and processes;however, if kept simple and prepared at large scale,they may help the local administrators and land-useplanners to reduce the socio-economic costs oflandslides. Furthermore, the comparative study oflandslide activity represents a relativelyinexpensive and quick method for evaluating theperformance of the engineering control efforts.The quantification of landslide activity in terms ofareal frequency can represent an additional step,useful to determine the relative landslide hazard(zonation in more or less hazardous areas). Forexample, the estimates of areal frequency of activelandsliding for the last 40 years demonstrated thegreat influence of the 1980 Irpinia earthquake(M_s = 6.9) on the stability of slopes situatedclose to its epicenter (within a radius of about20 km).  相似文献   

Crustal versus asthenospheric relaxation and post-seismic deformation for shallow normal faulting earthquakes:the Umbria–Marche (central Italy) case     

R. Riva  A. Aoudia  L. L. A. Vermeersen  R. Sabadini  & G. F. Panza 《Geophysical Journal International》2000,141(3):F7-F11

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Mud volcanoes of Italy     

Giovanni Martinelli  Alan Judd 《Geological Journal》2004,39(1):49-61

The locations and information about the sizes of 61 mud volcanoes on the Italian mainland and Sicily, plus an area of mud diapirism in the Italian Adriatic Sea, are presented. Data about the emission products are also provided. The majority of these mud volcanoes are found where thick sedimentary sequences occur within a zone of tectonic compression associated with local plate tectonic activity: the movement of the Adriatic microplate between the converging African and Eurasian plates. The principal gas emitted by these mud volcanoes is methane, which probably originates from deep within the sediments. Other mud volcanoes, associated with igneous volcanism, produce mainly carbon dioxide. The mud diapirs in the Adriatic Sea are thought to form as a result of the mobilization of shallow gassy sediments. It has been shown that radon emissions from mud volcanoes are indicators of forthcoming earthquake events. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

First Ar/Ar age of the Ceprano man (central Italy)     

Sébastien Nomade  Giovanni Muttoni  Hervé Guillou  Eric Robin  Giancarlo Scardia 《Quaternary Geochronology》2011,6(5):453-457

The Ceprano calvarium, found in 1994 in Italy and attributed to Homo cepranensis, is one of the most celebrated hominin remains of Europe. It was considered at least 700 ka-old until a recent investigation incorporating magnetostratigraphy and K-Ar ages from the literature assigned to the calvarium an age of ∼450 (+50, −100) ka. Here we pin down the age of the Ceprano calvarium to 353 ± 4 ka (±1σ external) by means of new ⁴⁰Ar/³⁹Ar dating on K-feldspars retrieved from the sediments that hosted the skull. In absence of evidence of reworking, this refined age sinks the conviction that H. cepranensis belonged to human evolution at the Brunhes–Matuyama boundary (c.a. 781 ka). Our refined age indicates that H. cepranensis lived in central Italy probably during the cold period of marine isotope stage (MIS) 10, and that despite his archaic morphology and lack of Neanderthal traits, he was contemporaneous with more advanced species such as H. heidelbergensis.  相似文献   

Sustained post-seismic effects on groundwater flow in fractured carbonate aquifers in Central Italy     

Lucia Mastrorillo  Michele Saroli  Stefano Viaroli  Francesca Banzato  Daniela Valigi  Marco Petitta 《水文研究》2020,34(5):1167-1181

A sustained increase in spring discharges was monitored after the 2016 Central Italy seismic sequence in the fractured carbonate aquifer of Valnerina–Sibillini Mts. The groundwater surplus recorded between August 2016 and November 2017 was determined to be between 400 and 500 × 10⁶ m³. In fractured aquifers, the post-seismic rise in spring discharges is generally attributed to an increase in bulk permeability caused by the fracture cleaning effect, which is induced by pore pressure propagation. In the studied aquifers, the large amount of additional discharge cannot only be attributed to the enhanced permeability, which was evaluated to be less than 20% after each main seismic event. A detailed analysis of the spring discharge hydrographs and of the water level at five gauging stations was carried out to determine the possible causes of this sudden increase in groundwater outflow. Taking into account the geological and structural framework, a conceptual model of a basin-in-series has been adopted to describe the complex hydrogeological setting, where the thrusts and extensional faults have clearly influenced the groundwater flow directions before and after the seismic sequence. The prevalent portion of the total post-seismic discharge surplus not explained by the increase in permeability has been attributed to changes in the hydraulic gradient that caused seismogenic fault rupture and the disruption in the upgradient sector of the aquifer. The additional flow calculated through the breach of the pre-existing hydrostructural barrier corresponds to approximately 470 × 10⁶ m³. This value is consistent with the total discharge increase measured in the whole study area, validating the proposed conceptual model. Consequently, a shift in the piezometric divide of the hydrogeological system has been induced, causing a potentially permanent change that lowers the discharge amount of the eastern springs.  相似文献   

Benthic foraminifera for heavy metal pollution monitoring: A case study from the central Adriatic Sea coast of Italy     

F. Frontalini  R. Coccioni 《Estuarine, Coastal and Shelf Science》2008

Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coastal and marginal marine settings. Their community structure provides information on the general characteristics of the environment and some species are sensitive to specific environmental parameters. Among various criteria, the occurrence of test abnormalities may represent a useful bioindicator for monitoring environmental impacts in coastal regions. A study of living benthic foraminifera was carried out in 42 sediment samples collected from the central Adriatic coast of Italy. Benthic foraminiferal assemblages from this area are rich, well preserved, and dominated by Ammonia parkinsoniana, and subordinately by Ammonia tepida, Aubignyna perlucida, Eggerella scabra, and Nonionella turgida. Heavy metal concentrations have been analysed which indicate low polluted environmental conditions. Foraminiferal species and heavy metal concentrations were investigated both with bivariate (correlation matrix) and multivariate techniques of principal component analysis (PCA) and cluster analysis. Statistical analysis shows a possible control of these pollutants both on the taxonomic composition of the benthic foraminiferal assemblages and the development of test malformations. Increasing heavy metal contents lead to an increase in relative abundance of A. tepida A. perlucida, N. turgida and E. scabra, and a relative concurrent decrease in relative abundance of A. parkinsoniana and higher percentages of deformed specimens (FAI) and species (FMI). Our results confirm that A. parkinsoniana prefers clean to low polluted environments and show that it is a very sensitive and un-tolerant species to heavy metal pollution being deeply affected by heavy metal content even at low concentrations. Our findings also confirm the capacity of the A. tepida to tolerate increasing heavy metal concentrations, and highlights that A. perlucida, N. turgida and E. scabra can be considered as tolerant species at least in low polluted environments. Following this, A. parkinsoniana and A. tepida can be reciprocally considered good bioindicator of heavy metal pollution over the surveyed area. The development of test abnormalities with a variety of malformations is a noticeable feature over the study area where the living deformed assemblages are largely dominated by a few species. The low percentages of deformed specimens (Foraminiferal Abnormality Index up to 4.7, with 2 on average) match well with the low concentrations of heavy metals that lead to low polluted environmental conditions. This study confirms and supports the suitability of studying benthic foraminifera as a technique for the in situ continuous bio-monitoring of heavy metal pollution of coastal marine sediments.  相似文献   

Impact of the magnitude and frequency of debris‐flow events on the evolution of an alpine alluvial fan during the last two centuries: responses to natural and anthropogenic controls     

Luca Colombera  Riccardo Bersezio 《地球表面变化过程与地形》2011,36(12):1632-1646

The dynamics and the surface evolution of a post‐LGM debris‐flow‐dominated alluvial fan (Tartano alluvial fan), which lies on the floor of an alpine valley (Valtellina, Northern Italy), have been investigated by means of an integrated study comprising geomorphological field work, a sedimentological study, photointerpretation, quantitative geomorphology, analysis of ancient to modern cartography and consultation of historical documents and records. The fan catchment meteoclimatic, geological and geomorphological characteristics result in fast rates of geomorphic reorganization of the fan surface (2 km²). The dynamics of the fan are determined by the alternation of low‐return period catastrophic alluvial events dominated by non‐cohesive debris flows triggered by extreme rainstorms which caused aggradation and steepening of the fan and avulsion of its main channel, with periods of low to moderate streamflow discharge punctuated by low‐ to intermediate‐magnitude flood events, causing slower but steady topographic reworking. The most ancient parts of the fan surface date back at least to the first half of the 19th century, but most of the fan surface has been restructured after 1911, mainly during the debris‐flow‐dominated events of 1911 and 1987. Phases of rapid fan toe incision and fan degradation have been recognized; since the 1930s or 1940s, the Tartano fan has been subjected to a state of deep entrenchment and narrowing of the main trunk channel and distributary area. Post‐Little Ice Age climate change and present‐day surface uplift rates have been considered as possible explanations for the observed geomorphic evolution, but tectonic or climatic controls cannot account for the order of magnitude of the erosional pace. Anthropogenic controls plausibly override the natural ones: in particular, the building of a dam in the late 1920s, about 2 km upstream of the fan, seems to have triggered fan dissection, having altered the sediment discharge through sediment retention. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Assessment of pH variability at a coastal CO₂ vent for ocean acidification studies     

Philip KerrisonJason M. Hall-Spencer  David J. SuggettLeanne J. Hepburn  Michael Steinke 《Estuarine, Coastal and Shelf Science》2011,94(2):129-137

Marine environments with naturally high CO₂ concentrations have become important research sites for studying the impacts of future ocean acidification on biological processes. We conducted high temporal resolution pH and temperature measurements in and around a shallow (2.5-3 m) CO₂ vent site off Ischia, Italy in May and June 2008. Loggers were deployed at five stations to monitor water at both the surface and benthos. Our reference station, 500 m from the CO₂ vent, had no noticeable vent influence. It had a naturally high and stable benthic pH (mean 8.16, inter-quartile range (IQ): 8.14-8.18) fluctuating with diel periodicity, presumably driven by community photosynthesis and respiration. A principal component analysis (PCA) revealed that the pH of this station was well constrained by meteorological parameters. In contrast, a station positioned within the vent zone, had a low and very variable benthic mean pH of 7.11 (IQ: 6.91-7.62) with large pH fluctuations not well constrained by a PCA. Any stations positioned within 20 m of the main vent zone had lowered pH, but suffered from abnormally large pH fluctuations making them unsuitable representatives to predict future changes to a shallow coastal environment. Between these extremes, we identified a benthic area with a lower pH of 7.84 (IQ: 7.83-7.88) that retained many of the characteristics of the reference station such as a natural diel pH periodicity and low variability. Our results indicate that a range of pH environments maybe commonplace near CO₂ vents due to their characteristic acidification of benthic water over a wide area. Such environments could become invaluable natural laboratories for ocean acidification research, closely mimicking future CO₂ conditions in a natural setting.  相似文献   

Role of slumped beds in the genesis and evolution of huge hypogean rooms: an example in the Valle del Nosê (Como,Northern Italy)     

Paola Tognini 《Geodinamica Acta》2013,26(5):335-343

Abstract

During a detailed structural analysis of the cave systems of the Valle del Nosê (Como, Northern Italy), a systematic occurrence of thick (metric to decametric) slumped beds in several huge rooms and in other wide underground voids was observed. The systematic control, that these structures exert on the morphologies of the karst systems, suggests that slumped beds might play a major role in the genesis and evolution of large underground voids. In fact, thanks to their very high permeability, these beds seem to be able to act as the preferential way for water flowing in the very first phases of karst development, thus guiding cave development, while their mechanical properties, different from those of unslumped beds, make them prone to break down collapse, thus increasing the possibilities of the formation of huge rooms. On the basis of the observed field data, a genetic and evolutive model is therefore suggested to explain the origin of the largest voids in this area. This model has by now a strictly local effectiveness. © 2000 Éditions scientifiques et médicales Elsevier SAS  相似文献   

The slope aspect: A predisposing factor for landsliding?     

Marco Capitani  Adriano Ribolini  Monica Bini 《Comptes Rendus Geoscience》2013,345(11-12):427-438

The influence of slope aspect on the distribution of landslides was studied in the Milia and Roglio basins in Tuscany, Italy. For each basin, the new Tuscany region landslide inventory that was initiated in 2010 was used. The landslides were split into separate datasets based on their prevailing movement typology. To assess the results that were obtained from the different slope aspect values, maps of the lithology, slope angle, distances to streams, and distances to tectonic lineaments were included in the bivariate statistical analysis as comparison terms. For each basin, all of the geo-environmental factor maps were compared with the different landslide typologies with GIS software. Pearson's Chi² (χ²) coefficient was used to test the degree of spatial association between each predictor variable and landslide type. In addition, Cramer's V test was used to quantify the strength of the degree of association. Next, a conditional analysis was applied to all of the possible combinations that occurred between the slope aspect and other landslide-predisposing factors. Overall, the slope aspect significantly affected the distribution of superficial landslide types, but apparently not that of other landslide types.  相似文献