Search results for "Debris flow"
showing 10 items of 33 documents
Prediction of debris-avalanches and -flows triggered by a tropical storm by using a stochastic approach: An application to the events occurred in Moc…
2019
Abstract Landslides are among the most dangerous natural processes. Debris avalanches and debris flows in particular have often caused casualties and severe damage to infrastructures in a wide range of environments. The assessment of susceptibility to these phenomena may help policy makers in mitigating the associated risk and thus it has attracted special attention in the last decades. In this experiment, we assessed susceptibility to debris-avalanche and -flow landslides by using a stochastic approach. Two different modeling techniques were employed: i) Multivariate Adaptive Regression Splines (MARS) and ii) Logistic Regression (LR). Both MARS and LR allow for calculating the probability …
Evaluation of debris flow susceptibility in El Salvador (CA): a comparison between Multivariate Adaptive Regression Splines (MARS) and Binary Logisti…
2018
In the studies of landslide susceptibility assessment, which have been developed in recent years, statistical methods have increasingly been applied. Among all, the BLR (Binary Logistic Regression) certainly finds a more extensive application while MARS (Multivariate Adaptive Regression Splines), despite the good performance and the innovation of the strategies of analysis, only recently began to be employed as a statistical tool for predicting landslide occurrence. The purpose of this research was to evaluate the predictive performance and identify possible drawbacks of the two statistical techniques mentioned above, focusing in particular on the prediction of debris flows. To this aim, an…
OPTIMIZING STOCHASTIC SUSCEPTIBILITY MODELLING FOR DEBRIS FLOW LANDSLIDES: PIXEL SIZE EFFECTS, PROBLEMS IN CHRONO-VALIDATION, 2D SPATIALLY DISTRIBUTE…
Hyperconcentrated flow and men velocity estimation: a study case
2015
Due to the complexity of the debris-flow process, numerical models to simulate propagation phenomenon are still limited. Different approaches (either monophase or two-phase) have been proposed in literature to solve the set of governing equations. But, the difficulty is due to the fact that these equations require suitable closure relations that should be valid in a very wide range of slope and materials characteristics. The point is that, in order to perform a hazard assessment and/or to design protective measures against debris flows, it is necessary to estimate important parameters such as mean flow velocity, peak discharge and runout distance. Experimental program has been recently cond…
Exploring relationships between pixel size and accuracy for debris flow susceptibility models: a test in the Giampilieri catchment (Sicily, Italy).
2014
Debris flows are among the most hazardous phenomena in nature, which typically take the form of multiple-occurrence regional landslide events triggered by intense driving inputs such as storms or earthquakes. The main tasks of this study were to verify whether cell-based susceptibility models is capable of predicting debris flow initiations in the Giampilieri catchment (southern Italy) and to explore the relationships between the pixel size of the adopted mapping units in terms of predictive performances of the derived models. The Giampilieri catchment is a small area (10km 2 ) hit by a storm on the 1 st October 2009 which resulted in the triggering of more than one thousand landslides and …
The flood of October 2009 and the effect on the Messina area.
2012
Flow characteristics of a channelized debris-flow and implications in numerical modelling: a study case
2012
As it is known, debris flows are characterized by extreme propagation rapidity and by the ability to move high quantity of fluid mass. Furthermore, debris flows are fluid enough to travel long distances and, thus, to cause damage in vast areas, even far from the trigger ones. Debris-flow runout estimations are important for the delineation of potentially hazardous areas. Especially in recent years, several researches have been conducted in order to define predicitive models. But, existing runout estimation methods need input parameters that can be difficult to estimate. Recent advances in theory and in experimental research have allowed the assessment of the physics of the debris flows. On …
158. Velocity estimation of high-concentrated flows: sensitivity analysis with main parameters included in the Bagnold equation
2017
As it is known, the propagation of debris flow causes huge territorial changes and damages in short times. The motion of debris flow is determined by gravity and it especially occurs in steep mountainous areas. Debris flow velocity is an important factor which influences the impact forces and runup. In this context, in the present work attention is restricted to Bagnolds Equation with the specific aim to assess the impact of the aforementioned assumptions in flow velocity estimation.
Estensione e ciclicità di accumuli debritici tardo-pleistocenici nei bacini di Sibari e Corigliano (Mar Ionio): implicazioni per la tettonica recente…
2013
Corpi sedimentari caratterizzati da facies sismica “trasparente” di notevole spessore (sino a 35 m) sono stati documentati in più livelli della copertura tardo-pleistocenica della Piana Abissale del Mar Ionio ed interpretati come megatorbiditi innescate da megatsunami. Il più recente di questi corpi è stato posto da Autori vari, in relazione ai collassi vulcanici del Santorini o dell’Etna o al sisma distruttivo di Creta del 365 d.C. [Polonia et al., 2013]. Corpi “trasparenti” di notevole spessore (15-30 m) e estensione (> di 100 km2), sono stati segnalati anche nel Mar Ionio nord-occidentale e interpretati come accumuli debritici tardo-pleistocenici-olocenici, presumibilmente sismoindotti […
La Franosità diffusa dell'1 Ottobre 2009 nel territorio ionico-peloritano della Provincia di Messina: stato delle indagini e prime considerazioni sul…
2009
A seguito di un evento estremo di pioggia verificatosi il 1 ottobre 2009 in un settore circoscritto del versante ionico della Provincia di Messina, si sono sviluppati numerosi eventi franosi classificabili per la maggior parte come colate di fango e detrito a rapida evoluzione (debris-mud flows). Dai primi sopralluoghi effettuati, in assenza ancora di un censimento sistematico, si sono riconosciuti eventi in numero di oltre 500, che hanno interessato sia nei versanti interni dei bacini idrografici che sversano nello Ionio, sia sui rilievi direttamente prospicienti la costa. L’elevato numero di eventi occorsi ha consentito di dettagliare dal punto di vista morfologico i fenomeni avvenuti e d…