0000000000899406
AUTHOR
Valerio Agnesi
Giants and elephants of Sicily
Slope units-based flow susceptibility model: using validation tests to select controlling factors
A susceptibility map for an area, which is representative in terms of both geologic setting and slope instability phenomena of large sectors of the Sicilian Apennines, was produced using slope units and a multiparametric univariate model. The study area, extending for approximately 90 km2, was partitioned into 774 slope units, whose expected landslide occurrence was estimated by averaging seven susceptibility values, determined for the selected controlling factors: lithology, mean slope gradient, stream power index at the foot, mean topographic wetness index and profile curvature, slope unit length, and altitude range. Each of the recognized 490 landslides was represented by its centroid po…
Evoluzione geomorfologica della Sicilia occidentale
La Franosità diffusa dell'1 Ottobre 2009 nel territorio ionico-peloritano della Provincia di Messina: stato delle indagini e prime considerazioni sulle dinamiche geomorfiche attivate.
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…
Il contributo delle riserve naturali alla tutela di aspetti geomorfologici significativi.
UTILIZZO DEL SISTEMA GOOGLE EARTH PER LA DEFINIZIONE DI UN MODELLO DI SUSCETTIBILITÀ DA FRANA: UN TEST IN SICILIA CENTRALE
Exploiting Google EarthTM to assess a landslide susceptibility model: a test in central Sicily. A landslide susceptibility multivariate model, based on the conditional analysis approach, has been derived in the Tumarrano river basin (about 78 km2), by intersecting a GIS grid layer, expressing some selected geo-environmental conditions (outcropping lithology, steepness, plan curvature and topographic wetness index), and a landslide vector archive, produced by a Google EarthTM aided remote survey. The analysis of the Google EarthTM images dated at 2006, allowed to recognize 733 landslides (30 rotational slides and 703 flows), almost exclusively affecting clay and sandy clay rocks. Validation …
MULTIVARIATE ANALYSIS OF GULLY-EROSION PROCESS: SUSCEPTIBILITY ASSESSMENT AND TEMPORAL VALIDATION IN A WATERSHED OF NORTH-CENTRAL SICILY, ITALY
CART-based gully types classification: a case study in Sicily (Italy)
Gulling is a complex process depending on several factors and involving a wide range of sub-processes. Different types of gullies were distinguished and described in literature. Their contribution to soil erosion changes in relation with the typology and their presence is influenced by different controlling factors. Mapping and classifying gullies is crucial for monitoring soil erosion. So far, no systematic definition of morphological characteristics of the different types of gullies and of their controlling factors has been made. The present work aims to suggest an innovative approach to automatically classify gullies by integrating remote sensing, GIS and a classification algorithm. The …
Sicily in the last one million years
The morphologic set up of Sicily is extremely varied and can generally be considered representative of different geomorphological contexts characterizing the Mediterranean area. Paleoenvironmental reconstructions regarding the Middle Pleistocene to Holocene are mostly based on paleontologic informations and geomorphologic data. The geodynamic evolution of Sicily, characterized by particularly active neotectonics that has caused the raising and emerging of large areas, has interacted with the significant climatic fluctuations and eustatic oscillations, aiding remarkably in the landscape evolution. Tree different period are analyzed: the environment during Middle Pleistocene and Early-Upper P…
Sicilia: bacini idrografici, corsi d'acqua e laghi
Il Museo Geologico del Geopark Madonie - Petralia Sottana
GIS-analysis of gully erosion susceptibility: a key study in north-central Sicily,Italy
Evoluzione morfotettonica della Sicilia nord occidentale
Validation of multivariated landslide hazard model in the Guddemi river basin (Northern Sicily,Iitaly)
Ruolo dei fenomeni di deformazione gravitativa profonda di versante nell'evoluzione geomorfologica di grandi rilievi carbonatici della Sicilia occidentale
Il carsismo nei rilievi carbonatici della Sicilia Nordoccidentale.
Le caratteristiche geomorfologiche delle Madonie
Identification and assessment of geosites for territorial enhancement – the study and geoheritage exploitation of the Torre Salsa natural reserve (Sicily)
The “Ecological Cross-‐border Networks Malta-‐Sicily” (RE.MA.SI.) is an international research project founded by the Italia-‐Malta 2007-‐2013 Programme. A part of the project aims to carry out a multidisciplinary study for the identification and enhancement of geosites in the Maltese Islands and Sicily. Some areas have been picked out; these areas are spectacular and interesting for the tourists and can make a significant contribution to the understanding the geological and geomorphological history. Field surveys took place for the identification and classification of the most significant geomorphosites and the verification of the collected bibliographical data; in particular, the iden…
Geomorphology of the urban area of Palermo (Italy)
The results of a geomorphological study carried out in the urban area of Palermo are summarized in a thematic map. Field survey, analysis of aerial photographs and topographic maps, consultation of historical documents and maps, stratigraphic and topographic reconstruction from numerous wells and subsoil data, and bibliographic search were performed, in order to display the geomorphological changes produced by man over time in a densely populated area and to define the Anthropocene of the study area. Palermo town rises along large marine terrace surfaces cut by small river valleys and bordered by wide degraded and abandoned coastal cliffs. Over the last 2700 years, this area was affected by…
Valutazione dell’erosione del suolo nel bacino del Fiume San Leonardo (Sicilia centro-occidentale, Italia).
Soil erosion by water in Mediterranean environment: direct and indirect appraisal from test areas and catchments (EROMED. A project of National Interest financed by the Italian Ministry of University and Research: organization, goals and first results.
Assessment of Gully Erosion Susceptibility Using Multivariate Adaptive Regression Splines and Accounting for Terrain Connectivity
In this work, we assessed gully erosion susceptibility in two adjacent cultivated catchments of Sicily (Italy) by employing multivariate adaptive regression splines (MARS) and a set of geo-environmental variables. To explore the influence of hydrological connectivity on gully occurrence we measured the changes of performance occurred when adding one by one nine predictors reflecting terrain connectivity to a base model that included contributing area and slope gradient. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to evaluate models performance. Gully predictive models were trained in both the catchments and submitted to internal (in the ca…
Exploring the effect of absence selection on landslide susceptibility models: A case study in Sicily, Italy
Abstract A statistical approach was employed to model the spatial distribution of rainfall-triggered landslides in two areas in Sicily (Italy) that occurred during the winter of 2004–2005. The investigated areas are located within the Belice River basin and extend for 38.5 and 10.3 km 2 , respectively. A landslide inventory was established for both areas using two Google Earth images taken on October 25th 2004 and on March 18th 2005, to map slope failures activated or reactivated during this interval. Geographic Information Systems (GIS) were used to prepare 5 m grids of the dependent variables (absence/presence of landslide) and independent variables (lithology and 13 DEM-derivatives). Mul…
A multi-scale regional landslide susceptibility assessment approach: the SUFRA_SICILIA (SUscettibilità da FRAna in Sicilia) project
The SUFRA project is based on a three level susceptibility mapping. According to the availability of more detailed data, the three scale for susceptibility mapping are increased respect to the ones suggested by the TIER group to 1:100,000, 1:50,000 and 1:25,000/1:10,000. The mapping levels exploit climatic, soil use (CORINE2009) and seismic informative layers, differentiating in the details of the core data (geology and topography), in the quality and resolution of the landslide inventory and in the modelling approach (Tab. 1). SUFRA_100 is based on a heuristic approach which is applied by processing a geologic layer (produced by ARTA integrating pre-CARG 1:100,000 geologic maps); the DEM e…
Geomorphological, chemical and physical study of “calanchi” landforms in NW Sicily (southern Italy)
Abstract This work deals with an integrated geomorphological and chemical–physical study of “calanchi” landforms in two sites (Ottosalme and Catalfimo) of NW Sicily (southern Italy), developed on dominant silty-clay deposits. The calanchi fronts are characterized by different morphological features and dominant geomorphic processes. Sharp knife-edged ridges and concentrated water runoff dominate at Ottosalme, and smoother landforms affected by mass movements (mud flows and translational slides) prevail at Catalfimo. We focused on some geochemical and physical parameters such as pH , total dissolved salts, sodium adsorption ratio ( SAR ), porosity, plastic and liquid limits as possible cause…
The geo-hydrologic event in the Peloritan – Ionian area of 2009: debris-flow susceptibility assessment by means of forward logistic regression
On the 1st of October 2009, the area centred on the village of Giampilieri (Messina), on the Ionian side of the Peloritan belt, suffered thousands of landslides activated in the time lapse of about five hours, which caused 36 victims, more than 100 injured and more than 0.5M€ of damage to structures. This unprecedented phenomenon was triggered by an exceptional meteorological event, recorded at the foothills with 250mm of rain in just 8 hours; this amount of rainfall was cumulated to two previous events (16/IX: 75mm; 23/IX: 190mm) for a total amount of more than 500mm in less than two weeks. Due to the peculiar triggering conditions a huge number of debris flows involved the shallow weather…
Storia delle conoscenze geografiche
Soil erosion in Mediterranean environment: The conceptual approach of the EROMED Project to assess regional impacts of global change in Italy.
L'ambiente fisico. Geomorfologia dell'area
The Madonie Geopark (Italy): geological and geomorphological features
Geomorphological map of the Madonie Park (Northern Central Sicily)
Landslide susceptibility assessment in Sicily: a key study in the central chain sector (Sicani Mounts)
Assessment of susceptibility to earth-flow landslide using logistic regression and multivariate adaptive regression splines: A case of the Belice River basin (western Sicily, Italy)
Abstract In this paper, terrain susceptibility to earth-flow occurrence was evaluated by using geographic information systems (GIS) and two statistical methods: Logistic regression (LR) and multivariate adaptive regression splines (MARS). LR has been already demonstrated to provide reliable predictions of earth-flow occurrence, whereas MARS, as far as we know, has never been used to generate earth-flow susceptibility models. The experiment was carried out in a basin of western Sicily (Italy), which extends for 51 km 2 and is severely affected by earth-flows. In total, we mapped 1376 earth-flows, covering an area of 4.59 km 2 . To explore the effect of pre-failure topography on earth-flow sp…
A multidisciplinary approach to the evaluation of the mechanism that triggered the Cerda landslide (Sicily, Italy).
Abstract The present paper describes a multidisciplinary approach to the evaluation of a seismically triggered landslide that occurred in the Cerda area (Italy) on September 6, 2002, about 1 h after an earthquake took place in the south Tyrrhenian Sea. The study was focused on an analysis of the role of the seismic input in triggering the landslide, in view of the evidence that no other mass movement was recorded in the adjacent areas despite geological and geomorphological spatial homogeneity. The studied area is located on a slope of the western flank of the Fiume Imera Settentrionale (Northern Sicily), which is made up of clayey–arenitic rocks. The slope inclines gently but is not unifor…
Soil erosion by water in Mediterranean environment: Italian assessment network of test areas and catchments (EROMED).
Earth-flow susceptibility assessment in the Marvello River basin (Sicily, Italy)
In this study, statistical models of earth-flow susceptibility were prepared using logistic regression. The analyses were carried out in a small (51 km2) basin of western Sicily, where 1,376 earth-flows were identified. To predict the spatial distribution of the mapped landslides, outcropping lithology and seven topographic attributes were exploited as explanatory variables. Before calculating these variables, a reconstruction of the pre-failure topography was performed. To evaluate the predictive skill and the robustness of the models, two groups made of five random subsets of earth-flows and stable cells were prepared. Absences of the first group were selected as individual cells whereas …
Sicilia nord-occidentale: dai Monti di Palermo al trapanese
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Evaluating the effects of man-induced topographic changes in landscape structure on soil erosion by water: a case study in Sicily
Palaeogeographical evolution of the Egadi Islands (western Sicily, Italy). Implications for late Pleistocene and early Holocene sea crossings by humans and other mammals in the western Mediterranean
Abstract The continental shelf morphology offshore of western Sicily suggests that during the Last Glacial Maximum (LGM, 20 ka cal BP), two of the Egadi Islands, Favignana and Levanzo, were connected to Sicily by a wide emerged plain, while Marettimo was only separated from the other islands by a narrow channel. We studied the relative sea-level variation from the LGM until today, focussing on two important time slices: the Mesolithic (9.5–13 ka cal BP) and the Neolithic (6.5–7.5 ka cal BP). In this research, we discuss a sea-level rise model by means of geomorphological, archaeological and geophysical observations and new radiocarbon dating of marine and terrestrial fossil fauna. The resul…
Water erosion susceptibility mapping by applying Stochastic Gradient Treeboost to the Imera Meridionale River Basin (Sicily, Italy)
Abstract Soil erosion by water constitutes a serious problem affecting various countries. In the last few years, a number of studies have adopted statistical approaches for erosion susceptibility zonation. In this study, the Stochastic Gradient Treeboost (SGT) was tested as a multivariate statistical tool for exploring, analyzing and predicting the spatial occurrence of rill–interrill erosion and gully erosion. This technique implements the stochastic gradient boosting algorithm with a tree-based method. The study area is a 9.5 km 2 river catchment located in central-northern Sicily (Italy), where water erosion processes are prevalent, and affect the agricultural productivity of local commu…
First study of gypsum karst in Sicily. The contribution of Olinto Marinelli and Mariano Gemmellaro
Predicting the landslides triggered by the 2009 96E/Ida tropical storms in the Ilopango caldera area (El Salvador, CA): optimizing MARS-based model building and validation strategies
The main topic of this research was to evaluate the effect in the performance of stochastic landslide susceptibility models, produced by differences between the triggering events of the calibration and validation datasets. In the Caldera Ilopango area (El Salvador), MARS (multivariate adaptive regression splines)-based susceptibility modeling was applied using a set of physical–environmental predictors and two remotely recognized landslide inventories: one dated at 2003 (1503 landslides), which was the result of a normal rainfall season, and one which was produced by the combined effect of the Ida hurricane and the 96E tropical depression in 2009 (2237 landslides). Both the event inventorie…
Bridging Malta and Sicily through geoheritage exploitation: Identification and assessment of geosites for territorial enhancement
Malta and Sicily show common geological and geomorphological features, having been also physically linked not later than the Last Glacial Maximum. At present both islands have a high tourist vocation, but their environmental potential is not fully exploited for attracting tourists and visitors. In the framework of an international research project, “Ecological Cross-border Networks Malta-Sicily” (RE.MA.SI.), a multidisciplinary study for the identification, selection and enhancement of geosites in the Maltese and Sicilian islands was carried out. A number of sites both in Malta and Sicily have been identified and qualitatively and quantitatively assessed applying a methodology already teste…
Quantitative analysis of “calanchi” slopes in northern Sicily: erosion rates and their relationships with rainfalls and physico-chemical properties of terrains
Geomorphological evolution of Pantelleria volcanic island, Sicily Channel
Multi-scale regional landslide susceptibility assessment in Sicily (Italy): The Sufra Sicilia Project
КАРТА ПОДВЕРЖЕННОСТИ ОПОЛЗНЕВОЙ ОПАСНОСТИ ТЕРРИТОРИИ РАЙОНОВ ШИЛАТО И КАЛЬТАВУТУРО (СЕВЕРНАЯ СИЦИЛИЯ). Logistic regression method for landslides susceptibility in Scillato and Caltavuturo river basin, Northern Sicily -
The studied area is located within two Sicilian districts– Scillato and Caltavuturo. Studied area is 200 km2. This territory is affected by large landslides very strongly. In the course of the research these districts were divided into 2 million square units of 10 × 10 m. Values of landslide factors were assessed within each unit. Using method of logistic regression allowed us to select the most significant factors and to make the landslide susceptibility map. Landslide hazard analys was made with 3 models, which analyze different diagnostic areas (places, where landslides are trigger usually). The results indicate that the using of the buffer zone with radius 50 m around the highest point …
IL MUSEO GEOLOGICO “G. G. GEMMELLARO” TRA STORIA E MEMORIA
Morphoevolutive models of the deep-seated gravitational slope deformation phenomena in Sicily Chain
Un approccio multi-scala per la valutazione della suscettibilità da frana a livello regionale: il progetto SUFRA (SUscettibilità da FRAna) in Sicilia
L’attuale versione del PAI (Piano Stralcio per l'Assetto Idrogeologico) disponibile per il territorio siciliano è fortemente dipendente dallo scenario di dissesti passati censiti e catalogati, sulla base dei quali, utilizzando un sistema di matrici di valutazione, è possibile ricavare le condizioni di rischio geomorfologico associato. Questo stadio costituisce un primo grande avanzamento delle conoscenze a partire dal quale è ora necessario procedere alla valutazione della suscettibilità da frana e all’adozione dunque di uno strumento di analisi territoriale con carattere previsionale. La realizzazione di una cartografia della suscettibilità da frana a scala regionale pone d’altra parte una…
L'Ambiente fisico. Inquadramento geografico-storico
L'evoluzione delle Saline attraverso lo studio cartografico.
Pantelleria island (Strait of Sicily): volcanic history and geomorphological landscape
Pantelleria is a volcanic island located in the Strait of Sicily, 95 km far from the Sicilian coastline and 67 km from Cape Bon (Tunisia). The volcanological history of the island begins approximately 324 ka BP and the last eruptive event was a submarine eruption that occurred on 1891 A.D. Eruptive activity was characterized by seven very intense explosive events, the latest being the Green Tuff (44 ka). They have all produced ignimbrite sheets that covered large sectors of the island. The landscape of the island mirrors the variety of the eruptive styles and their interplay with volcano-tectonics. The most evident geomorphological features are represented by: (i) the mantle-like distributi…
Landslide hazard analysis in the Iato River basin
Modelli predittivi di morfologie erosive e di frana nell'area di testata del bacino del fiume Imera Meridionale, Sicilia (Italia)
The 1st October 2009 Messina debris flows: first analysis for a susceptibility model
Le ricerche geologiche
Stop 3.1: Monte Pellegrino
Gully erosion susceptibility assessment by means of GIS-based logistic regression: A case of Sicily (Italy)
article i nfo Article history: This research aims at characterizing susceptibility conditions to gully erosion by means of GIS and multivariate statistical analysis. The study area is a 9.5 km 2 river catchment in central-northern Sicily, where agriculture ac- tivities are limited by intense erosion. By means of field surveys and interpretation of aerial images, we prepared a digitalmap of thespatial distribution of 260 gulliesinthestudy area.Inaddition,fromavailable thematicmaps, a 5 m cell size digital elevation model and field checks, we derived 27 environmental attributes that describe the variability of lithology, land use, topography and road position. These attributes were selected f…
An example of geological path in the Madonie Park (Sicily): the geological path n. 1 “Inghiottitoio della Battaglietta – Portella Colla”.
La Geomorfologia
Comparing Logistic Regression and MARS approaches for gully erosion susceptibility evaluation in central-northern Sicily
Dal tempo biblico al tempo geologico
I primi studi sul carsismo nei gessi della Sicilia. Il contributo di Olinto Marinelli e di Mariano Gemmellaro
Le Riserve Naturali nei Progetti di Educazione Ambientale
Stop 3.2: Alcamo Cappuccini
New Knowledge on the Monte Conca gypsum karst system (Central-Western Sicily).
Schema geomorfologico della Penisola di Capo San Vito (Sicilia nord-occidentale)
Confronto di due approcci statistici non parametrici per la valutazione della suscettibilità da frana nella catena appenninica settentrionale siciliana: tavolette I.G.M.I. Scillato e Caltavuturo
Oggigiorno, la valutazione della diversa importanza delle variabili geoambientali nel determinare le condizioni di suscettibilità da frana di un’area è uno dei problemi più attuali della geologia. L’uso ed il confronto di due differenti approcci statistici, ha consentito di stimare le condizioni di predisposizione all’instabilità gravitativa dei versanti, per un esteso settore settentrionale della catena appenninica siciliana, ricadente all’interno delle tavolette I.G.M.I. nn. 259 I SE “Scillato” e 259 II NE “Caltavuturo”. L’area oggetto della sperimentazione, estesa circa 200 Km2, è stata suddivisa in maniera semi-automatica in 1827 unità idro-morfologiche o unità di versante. Per ciascun’…
Geomorphology of the Capo San Vito Peninsula (NW Sicily): An Example of Tectonically and Climatically Controlled Landscape
The Capo San Vito peninsula is located along the north-westernmost sector of the Sicilian coastline. It is characterized by a complex geomorphological setting, where a large variety of coastal, gravity-induced and karst landforms allow the visitor to easily detect the interactions between Quaternary tectonics and climate changes as well as morphodynamic processes responsible for shaping the landscape. Thanks to natural reserves, the peninsula preserves a typical Mediterranean natural environment, marked by spectacular and suggestive landforms.
Gully Erosion susceptibility assesment: a case study in the Magazzolo River Basin, Sicily, Italy.
Il carsismo nei rilievi carbonatici della Sicilia nord occidentale (Carbonate Karst in the NW Sicily)
The great landslide at Portella Colla (Madonie, Sicily)
The South Western area of the Madonie Mountains is affected by large landslides; the major one developed starting from Portella Colla down to the Imera Settentrionale river, for a maximum length of about 6.2 km in a NE-SW direction. The study of the landslide, with the aim of reconstructing the geological, geomorphological and evolutionary aspects, has been carried out using integrated methodologies, including some geophysical investigations (in particular geoelectrical prospecting). The landslide is complex and characterized by superficial and deep gravitational deformations. The movement began in the Upper Pliocene and it is still active. The origin and evolution of the landslide are link…
Inquadramento geografico
Optimal slope units partitioning in landslide susceptibility mapping
In landslide susceptibility modeling, the selection of the mapping units is a very relevant topic both in terms of geomorphological adequacy and suitability of the models and final maps. In this paper, a test to integrate pixels and slope units is presented. MARS (Multivariate Adaptive Regression Splines) modeling was applied to assess landslide susceptibility based on a 12 predictors and a 1608 cases database. A pixel-based model was prepared and the scores zoned into 10 different types of slope units, obtained by differently combining two half-basin (HB) and four landform classification (LCL) coverages. The predictive performance of the 10 models were then compared to select the best perf…
Predicting storm-triggered debris flow events: application to the 2009 Ionian Peloritan disaster (Sicily, Italy)
Abstract. The main assumption on which landslide susceptibility assessment by means of stochastic modelling lies is that the past is the key to the future. As a consequence, a stochastic model able to classify past known landslide events should be able to predict a future unknown scenario as well. However, storm-triggered multiple debris flow events in the Mediterranean region could pose some limits on the operative validity of such an expectation, as they are typically resultant of a randomness in time recurrence and magnitude and a great spatial variability, even at the scale of small catchments. This is the case for the 2007 and 2009 storm events, which recently hit north-eastern Sicily …
Malta and Sicily Joined by Geoheritage Enhancement and Geotourism within the Framework of Land Management and Development
Malta and Sicily, which lie at the centre of the Mediterranean Sea, share a long history and have unique geological and geomorphological features which make them attractive destinations for geotourism. In the framework of an international research project, a study for the identification, selection and assessment of the rich geological heritage of Malta and Sicily was carried out, aiming to create a geosite network between these islands. Based on the experience and outputs achieved in previous investigations on geoheritage assessment carried out in various morpho-climatic contexts, an integrated methodology was applied for the selection, numerical assessment and ranking of geosites. The sele…
La Grotta di Carburangeli – ricostruzione climatica dell’Olocene per la piana costiera della Sicilia nord-occidentale
Giants end Elephants of Sicily
The great abundance of fascinating and impressive natural phenomena, like the active volcanoes, the thermal springs or the earthquakes, have fed the imagination of men, who have interpreted them as the manifestation of the existence of supernatural and fantastic beings giving rise to myth and legend. Among so many myths one particularly, that of the Cyclops Polyphemus, is closely linked to the geopalaeontological history of the Sicilian island. The discovery, often inside caves, of the fossil skulls of elephants, in which (in the frontal part) there is a great nasal hollow where during life there was the trunk, gave birth to the belief that one-eyed giants had existed, in past times; in fac…
Geological Path n.1.
Multi-parametric GIS analysis to assess gully erosion susceptibility: a test in southern Sicily, Italy
: A GIS-analysis was carried out in a test basin of southern Sicily, the Magazzolo River basin, in order to assess susceptibility conditions to gully erosion phenomena. The linear density of ephemeral and permanent gullies computed within each class of nine environmental variables was used to generate a gully erosion susceptibility map for the area. A validation procedure carried out in order to test the reliability of the adopted method highlighted a clear correlation between the occurrence of gullies and the computed susceptibility levels
Atlante dei Centri Abitati Instabili della Sicilia. Vol II - Provincia di Palermo
Geomorphological setting of Madonie Geopark (Italy)
The Madonie Natural Park is characterized by relevant zoological and botanic aspects and by geological features so remarkable that since 2001 it has been incorporated into the European Geoparks Network. The Park is marked by a wide massif know as Madonie Mountains. In this area, segment of the Maghrebide-Apenninic chain, successions of Meso-Cenozoic lithologies and late- and post-orogenic deposits occur. The geomorphological setting is extremely varied and includes many landscapes characterising several Sicilian areas; it results from the interaction between geomorphological processes, tectonic movements and climatic changes. It is possible to identify five distinct sectors, each correspond…
Geositi nel paesaggio mediterraneo: confronto tra aree costiere maltesi e siciliane
Geomorphology of the Anthropocene in Mediterranean urban areas
Urban-geomorphology studies in historical cities provide a significant contribution towards the broad definition of the Anthropocene, perhaps even including its consideration as a new unit of geological time. Specific methodological approaches to recognize and map landforms in urban environments, where human-induced geomorphic processes have often overcome the natural ones, are proposed. This paper reports the results from, and comparison of, studies conducted in coastal historical cities facing the core of the Mediterranean Sea – that is, Genoa, Rome, Naples, Palermo (Italy) and Patras (Greece). Their settlements were facilitated by similar climatic and geographical contexts, with high gr…
Landslide hazard analysis using GIS, Fiumara di Rosmarino, North-Eastern Sicily
The geological history of the Mediterranean (La storia geologica del Mediterraneo)
Gypsum karst caves versus surface landforms to define a morphoevolutive model in Central Southern Sicily (Southern Italy)
L'ambiente fisico e il paesaggio in Sicilia
Landslide susceptibility zonation by exploiting GIS tools and two statistical methods: binary logistic regression and multivariate adaptive regression splines. A test in western Sicily (Italy)
In the recent years advanced statistical methods and GIS tools have been frequently used to assess landslide susceptibility. The latter is estimated by establishing statistical relationships between landscape characteristics and spatial distribution of past slope-failures. These are mapped mainly by recognizing changes on slope morphology produced by gravity. Despite of this, most of the researches on landslide susceptibility do not consider that slope-failures modify topography and associate high probability of landsliding with topographic characteristics that differ from those that led slope-failures. In this research we analyzed landslide susceptibility in the basin of the Malvello river…
Geologia e geomorfologia di Pantelleria con particolare riferimento al settore costiero di Scauri
Inquadramento geologico e geomorfologico dell'area. L'evoluzione delle saline attraverso lo studio cartografico.
The Madonie Park geological guide
Realizzazione di una rete di monitoraggio geodetico della frana di Scopello (Sicilia nord-occidentale)
L’area di Scopello (Sicilia Nord-Occidentale) è da tempo oggetto di studi che, sulla base di osservazioni e rilievi geomorfologici, hanno consentito sia di riconoscere la presenza di frane superficiali e di fenomeni di deformazione gravitativa profonda di versante (DGPV), sia di ipotizzare cause e tipologie dei movimenti in atto, giungendo alla definizione di un primo modello interpretativo. I movimenti franosi si sviluppano lungo i settori costieri dell’area di Scopello, dove è a giorno un piano di sovrascorrimento del Miocene superiore, che vede la sovrapposizione di unità rigide, costituite da successioni carbonatiche meso-cenozoiche, su unità duttili, costituite, al tetto, da argille-ma…
Geomorphological evolution of western Sicily, Italy
Abstract This paper proposes a morphoevolutionary model for western Sicily. Sicily is a chain–foredeep–foreland system still being built, with tectonic activity involving uplift which tends to create new relief. To reconstruct the morphoevolutionary model, geological, and geomorphological studies were done on the basis of field survey and aerial photographic interpretation. The collected data show large areas characterized by specific geological, geomorphological, and topographical settings with rocks, landforms, and landscapes progressively older from south to north Sicily. The achieved results display: (1) gradual emersion of new areas due to uplift, its interaction with the Quaternary gl…
The role of the diagnostic areas in the assessment of landslide susceptibility models: a test in the sicilian chain
Abstract The aim of the research was to verify and compare the predictive power of different diagnostic areas in assessing landslide susceptibility with a multivariate approach. Scarps, landslide areas (the union between scarp and accumulation zones) and areas uphill from crowns, for rotational slides, source or scarp areas and landslide areas, for flows, have been tested. A multivariate approach was applied to assess the landslide susceptibility on the basis of three selected conditioning factors (lithology, slope angle, and topographic wetness index), which were combined in a Unique Condition Unit (UCU) layer. By intersecting the UCU layer with the vector layer of the diagnostic areas, la…
GUIDA GEOLOGICA DEL PARCO DELLE MADONIE
GPS Monitoring of the Scopello (Sicily, Italy) DGSD Phenomenon: Relationships Between Surficial and Deep-Seated Morphodynamics
The Scopello area, which is located along the north-western Tyrrhenian coastal sector of the Sicilian chain (Italy), is widely affected by Deep-seated Gravitational Slope Deformation (DGSD) phenomena, which are mainly the result of a geomorphologic setting marked by the outcropping of an overthrust plan, limiting a brittle fractured carbonate slab, laid onto a ductile marly-clayey substratum. Due to the very advanced stage of the deformation phenomena, a coupled morphodynamic style has established between shallow landslides and DGSD phenomena, affecting the exhumed ductile substratum and the overlaying rigid dismantled slab, respectively. A GPS network was realized for monitoring the Scopel…
Proposta di istituzione del Geosito. Motivazione e localizzazione
Tav. 66. Stromboli e Vulcano
Evaluation of debris flow susceptibility in El Salvador (CA): a comparison between Multivariate Adaptive Regression Splines (MARS) and Binary Logistic Regression (BLR)
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…
Geologia e Geomorfologia dell'area.
A GIS-based approach for gully erosion susceptibility modelling: a test in Sicily, Italy
The aim of this study is to analyze the susceptibility conditions to gully erosion phenomena in the Magazzolo River basin and to test a method that allows for driving the factors selection. The study area is one of the largest (225 km2) watershed of southern Sicily and it is mostly characterized by gentle slopes carved into clayey and evaporitic sediments, except for the northern sector where carbonatic rocks give rise to steep slopes. In order to obtain a quantitative evaluation of gully erosion susceptibility, statistical relationships between the spatial distributions of gullies affecting the area and a set of twelve environmental variables were analyzed. Stereoscopic analysis of aerial …