The rainfall intensity–duration control of shallow landslides and debris flows: an update     

Fausto Guzzetti  Silvia Peruccacci  Mauro Rossi  Colin P. Stark 《Landslides》2008,5(1):3-17

A global database of 2,626 rainfall events that have resulted in shallow landslides and debris flows was compiled through a thorough literature search. The rainfall and landslide information was used to update the dependency of the minimum level of rainfall duration and intensity likely to result in shallow landslides and debris flows established by Nel Caine in 1980. The rainfall intensity–duration (ID) values were plotted in logarithmic coordinates, and it was established that with increased rainfall duration, the minimum average intensity likely to trigger shallow slope failures decreases linearly, in the range of durations from 10 min to 35 days. The minimum ID for the possible initiation of shallow landslides and debris flows was determined. The threshold curve was obtained from the rainfall data using an objective statistical technique. To cope with differences in the intensity and duration of rainfall likely to result in shallow slope failures in different climatic regions, the rainfall information was normalized to the mean annual precipitation and the rainy-day normal. Climate information was obtained from the global climate dataset compiled by the Climate Research Unit of the East Anglia University. The obtained global ID thresholds are significantly lower than the threshold proposed by Caine (Geogr Ann A 62:23–27, 1980), and lower than other global thresholds proposed in the literature. The new global ID thresholds can be used in a worldwide operational landslide warning system based on global precipitation measurements where local and regional thresholds are not available..  相似文献   

Data trustworthiness and user reputation as indicators of VGI quality     

Paolo Fogliaroni  Fausto D’Antonio 《地球空间信息科学学报》2018,21(3):213-233

ABSTRACT

Volunteered geographic information (VGI) has entered a phase where there are both a substantial amount of crowdsourced information available and a big interest in using it by organizations. But the issue of deciding the quality of VGI without resorting to a comparison with authoritative data remains an open challenge. This article first formulates the problem of quality assessment of VGI data. Then presents a model to measure trustworthiness of information and reputation of contributors by analyzing geometric, qualitative, and semantic aspects of edits over time. An implementation of the model is running on a small data-set for a preliminary empirical validation. The results indicate that the computed trustworthiness provides a valid approximation of VGI quality.  相似文献   

An algorithm for the objective reconstruction of rainfall events responsible for landslides   总被引：2，自引：2，他引：0  

Massimo Melillo  Maria Teresa Brunetti  Silvia Peruccacci  Stefano Luigi Gariano  Fausto Guzzetti 《Landslides》2015,12(2):311-320

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Correction to: Impact of climate change on landslides frequency: the Esino river basin case study (Central Italy)     

Lorenzo Sangelantoni  Eleonora Gioia  Fausto Marincioni 《Natural Hazards》2018,92(2):885-905

We refine the 1-D velocity model of the Central India Tectonic Zone (CITZ) using well-selected arrival times of P- and S-phases of 354 local earthquakes of magnitude (M_w) between 2.0 and 5.8, recorded by national seismic network from May 1997 to March 2016. Further, we have determined the source mechanisms of 26 selected local events using moment tensor inversion to characterize the dynamics beneath the CITZ. The best-fit simulation between observed and synthetic waveforms obtained the nodal and auxiliary planes of the each faults associated with the earthquake moment magnitude (M_w) for each event. Depth of the fault plane along the CITZ varies from 5 to 38 km. From this study, we found that the western part along the CITZ shows minimum focal depth and reaches maximum 38 kms at Jabalpur in the eastern part. This complex nature of earthquake dynamics occurrence along the CITZ. We propose that the curviplanar the CITZ dominated with sinistral curvature is subjected to compression along the longer ~E–W segments and transtension along shorter segments with ~NE–SW orientations. The occurrences of normal faulting, intrusion of mafic plutons and CLVD mechanisms for earthquakes are interpreted to be linked to the transtension zones and reverse mechanisms associated with the compressions along ~E–W segments.  相似文献   

Comparing landslide inventory maps   总被引：10，自引：1，他引：9  

Mirco Galli  Francesca Ardizzone  Mauro Cardinali  Fausto Guzzetti  Paola Reichenbach 《Geomorphology》2008,94(3-4):268

Landslide inventory maps are effective and easily understandable products for both experts, such as geomorphologists, and for non experts, including decision-makers, planners, and civil defense managers. Landslide inventories are essential to understand the evolution of landscapes, and to ascertain landslide susceptibility and hazard. Despite landslide maps being compiled every year in the word at different scales, limited efforts are made to critically compare landslide maps prepared using different techniques or by different investigators. Based on the experience gained in 20 years of landslide mapping in Italy, and on the limited literature on landslide inventory assessment, we propose a general framework for the quantitative comparison of landslide inventory maps. To test the proposed framework we exploit three inventory maps. The first map is a reconnaissance landslide inventory prepared for the Umbria region, in central Italy. The second map is a detailed geomorphological landslide map, also prepared for the Umbria region. The third map is a multi-temporal landslide inventory compiled for the Collazzone area, in central Umbria. Results of the experiment allow for establishing how well the individual inventories describe the location, type and abundance of landslides, to what extent the landslide maps can be used to determine the frequency-area statistics of the slope failures, and the significance of the inventory maps as predictors of landslide susceptibility. We further use the results obtained in the Collazzone area to estimate the quality and completeness of the two regional landslide inventory maps, and to outline general advantages and limitations of the techniques used to complete the inventories.  相似文献   

Analysis of historical landslide time series in the Emilia‐Romagna region,northern Italy     

Mauro Rossi  Annette Witt  Fausto Guzzetti  Bruce D. Malamud  Silvia Peruccacci 《地球表面变化过程与地形》2010,35(10):1123-1137

A catalogue of historical landslides, 1951–2002, for three provinces in the Emilia‐Romagna region of northern Italy is presented and its statistical properties studied. The catalogue consists of 2255 reported landslides and is based on historical archives and chronicles. We use two measures for the intensity of landsliding over time: (i) the number of reported landslides in a day (D_L) and (ii) the number of reported landslides in an event (S_event), where an event is one or more consecutive days with landsliding. From 1951–2002 in our study area there were 1057 days with 1 ≤ D_L ≤?45 landslides per day, and 596 events with 1 ≤ S_event ≤ 129 landslides per event. In the first set of analyses, we find that the probability density of landslide intensities in the time series are power‐law distributed over at least two‐orders of magnitude, with exponent of about ?2·0. Although our data is a proxy for landsliding built from newspaper reports, it is the first tentative evidence that the frequency‐size of triggered landslide events over time (not just the landslides in a given triggered event), like earthquakes, scale as a power‐law or other heavy‐tailed distributions. If confirmed, this could have important implications for risk assessment and erosion modelling in a given area. In our second set of analyses, we find that for short antecedent rainfall periods, the minimum amount of rainfall necessary to trigger landslides varies considerably with the intensity of the landsliding (D_L and S_event); whereas for long antecedent periods the magnitude is largely independent of the cumulative amount of rainfall, and the largest values of landslide intensity are always preceded by abundant rainfall. Further, the analysis of the rainfall trend suggests that the trigger of landslides in the study area is related to seasonal rainfall. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Improvement of HVSR technique by wavelet analysis     

Roberto Carniel  Petra Malisan  Fausto Barazza  Stefano Grimaz 《Soil Dynamics and Earthquake Engineering》2008,28(4):321-327

In this work we investigate the application of the wavelet analysis to improve the well-known horizontal to vertical spectral ratio (HVSR) technique for site effect estimation. Wavelet analysis has been widely used in the last decade for its capacity to localise the signal in both the time and frequency domains. The wavelet packet transform and the evaluation of a cost function for every node permit one to remove from the signal the least important components and lead to significant improvements in the identification of the fundamental frequency. In this paper a new algorithm is presented based on wavelet analysis, that allows, in some cases, to improve the identification of the peak in the QTS ratio. A number of examples of application are also presented.  相似文献   

Landslide distribution and size in response to Quaternary fault activity: the Peloritani Range,NE Sicily,Italy          下载免费PDF全文

Francesco Bucci  Michele Santangelo  Mauro Cardinali  Federica Fiorucci  Fausto Guzzetti 《地球表面变化过程与地形》2016,41(5):711-720

Landslides contribute to dismantle active mountain ranges and faults control the location of landslides. Yet, evidence of the long‐term, regional dependency of landslides on active faults is limited. Previous studies focused on the transient effects of earthquakes on slope stability in compressive and transcurrent regimes. Here we show that in the Peloritani range, NE Sicily, Italy, one of the fastest uplifting areas in the Mediterranean, a clear geographical association exists between large bedrock landslides and active normal faults of the Messina Straits graben. By interpreting aerial photographs, we mapped 1590 landslides and sackungs and 626 fault elements and their facets in a 300 km² area in the eastern part of the range. We used the new landslide and fault information, in combination with prior geological and seismic information, to investigate the association between bedrock landslides and faults. We find that the distribution and abundance of landslides is related to the presence of large active normal faults, and matches the pattern of the local historical seismicity. Landslide material is more abundant along the East Peloritani Fault System where the long‐term activity of the faults, measured by the average yearly geological moment rate, is larger than in the West Peloritani Fault System where landslides are less abundant. Along the fault systems landslide material concentrates where the cumulated fault throws are largest. We conclude that large landslides and their cumulated volume are sensitive to local rates of tectonic deformation, and discriminate the deformation of the single fault segments that dissect the Peloritani range. Our findings are a direct test of landscape evolution models that predict higher rates of landslide activity near active faults. Our work opens up the possibility of exploiting accurate landslide and fault maps, in combination with geological and seismic information, to characterize the long‐term seismic history of poorly instrumented active regions. © 2015 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd  相似文献   

Macro benthic community assemblage before and after the 2007 tsunami and earthquake at Paracas Bay,Peru     

Betina J. Lomovasky  Fausto N. Firstater  Alex Gamarra Salazar  Jaime Mendo  Oscar O. Iribarne 《Journal of Sea Research》2011,65(2):205-212

Macrobenthic soft bottom community assemblages were studied from December 2006 to December 2007 at Paracas Bay (Atenas Beach, 13°45' S, 76°17' W, Peru), including the period of the tsunami of 15 August 2007, providing a unique opportunity to assess the effects of this type of natural disturbance in soft bottom marine ecosystems. The results show that the tsunami affected the soft bottom community assemblage by changing the sediment granulometry, the biomass and abundance of epifaunal species, and by increasing the silt proportion. The event affected all functional groups, resulting in an increased numbers and biomass of filter feeder and grazers that were followed soon after by predators during the post-tsunami period. A similar pattern was observed for biomass and the abundance of infaunal species without changing the functional groups. The slow recovery observed after four months was likely related to the loss of sediment stability. In summary, there were differences in the structure and composition of soft bottom macrofaunal assemblages before and after the earthquake and posterior tsunami disturbance, forcing benthic communities to initiate re-colonisation processes.  相似文献   

Can a Simulated Flood Experience Improve Social Resilience to Disasters?     

Maria Teresa Carone  Loris Melchiorri  Francesco Romagnoli  Fausto Marincioni 《The Professional geographer》2013,65(4):604-615

The increase of extreme meteorological phenomena, along with continuous population growth, has led to a rising number of flooding disasters. Therefore, there is an urgent need to develop better risk reduction strategies, among which is increased social resilience. Experiencing a disaster is recognized as a factor that positively influences overall community resilience, with particular effects on social resilience; it appears to be more influential than school education. It also has many negative effects, though. Previous studies underline that citizens do not distinguish between different types of experiences. Thus, we investigated whether a simulated experience of a flood can improve social resilience, without being hampered by negative repercussions. The study was executed in five municipalities in three Italian regions involved in the European project LIFE PRIMES, which planned simulation activities for each studied area. Data, collected through the administration of anonymous questionnaires before and after a flood drill, were processed by applying a multicriteria decision analysis tool (PROMETHEE). Results show that the drill significantly augmented perceived social resilience in the smaller studied communities but not in the larger ones, a fact that should be further investigated. Key Words: multicriteria decision analysis, simulated flood experience, social resilience to disasters.  相似文献