The availability of large environmental datasets and increased computational capability has motivated researchers to propose innovative techniques to mine information from data. The Evolutionary Polynomial Regression (EPR) is a hybrid data-driven technique that combines genetic algorithms and numerical regression for developing easily interpretable mathematical model expressions. EPR is a multi-objective search paradigm for producing multiple models by simultaneously optimizing accuracy and parsimony of resulting expressions. The EPR MOGA-XL is an MS-Excel add-in that allows the user to launch an EPR run as a function in MS-Excel, thereby exploiting a familiar environment to perform data-driven modeling. Inputs and outputs can be easily selected from a spreadsheet, while a separate sheet containing all EPR modeling options can be modified and retrieved for future analyses. The expression(s) of model(s) obtained, the model predictions and fitness indicators are stored in a separate Excel file, allowing subsequent multiple analyses. An application of EPR-MOGA-XL is presented and discussed.

An analysis of runoff generation through ephemeral streams in karst semi-arid areas is here presented. The analysis is based on a full 2D approach, integrating the hydrological and hydraulic models, in order to account first for the dynamic of catchment response to rainfall and activation of the streams, and then for the hydraulic behavior of the streams. This analysis entails the simulation of extreme events corresponding to low, medium and high return periods, in order to identify the event, which presumably activate the ephemeral streams. The analysis focuses on a case study located in southeast Italy.

The availability of large environmental datasets and increased computational capability has motivated researchers to propose innovative techniques to mine information from data. The Evolutionary Polynomial Regression (EPR) is a hybrid data-driven technique that combines genetic algorithms and numerical regression for developing easily interpretable mathematical model expressions. EPR is a multiobjective search paradigm for producing multiple models by simultaneously optimizing accuracy and parsimony of resulting expressions. Here the EPR MOGAXL v.1 is presented. It is an MS-Excel add-in that allows the user to launch an EPR run as a function in MS-Excel, thereby exploiting a familiar environment to perform data-driven modeling. Inputs and outputs can be easily selected from a spreadsheet, while a separate sheet containing all EPR modeling options can be modified and retrieved for future analyses. The expression(s) of model(s) obtained, the model predictions and fitness indicators are stored in a separate Excel file, allowing subsequent multiple analyses. An application of EPR-MOGA-XL is presented and discussed.

Ephemeral streams are morphological elements of karstic low-relief areas, characterised by relatively large and flat transects, which occasionally drains runoff, in particular when generated by extraordinary or extreme rainfall events. The main problem related to this streams and affecting the analysis and prediction of flood events in karst semi-arid regions is the almost complete absence of discharge time-series. Floods are relatively rare events for semi-arid karst regions, however they can be really severe and disruptive, causing serious damages to people and infrastructures. This work presents an analysis of the response to rainfall of ephemeral streamsin a karst semi-arid regions of south-east of Italy by an innovative approach. The analysis is based on a 2D simulation model of the behavior of a network of ephemeral streams. The used approach integrates the hydrological and hydraulic models, in order to account first for the dynamic of catchment response to rainfall and activation of the streams, and then for the hydraulic behavior of the streams. Results shows the slow response of ephemeral streams to the rainfall, whereas more extreme rainfall events generate quick and high discharge responses of the ephemeral streams. In addition, modeling results emphasize the non-linearity of runoff generation, in particular for some flow paths, which are biased by the local morphology as well as by the intensity of the rainfall event.

The toe of landslides is subject to compression stresses induced by the upward sliding masses and often characterized by a compression structure. These structures can evolve in passive toe thrust, which bias the geomorphologic evolution of the toe zone, particularly for prevailing longitudinal dimension landslide. This work presents a simple analytic model of the passive thrust at the toe of landslide based on the infinite slope approach to stability analysis. It is based on the analysis of the state of stresses according to Mohr circle representation and can be implemented also into a spread-sheet and making it possible to evaluate the form of failure surface at the toe of the landslide and the shear strength contribution to the factor of safety of a landslide.

The analysis of the dynamic response of shallow aquifers to rainfall is a hot topic for groundwater resources management. A data-driven methodology namely Evolutionary Polynomial Regression is here undertaken to perform this kind of analysis. The introduced methodology is an evolutionary modeling approach, , based on the multiobjective evolution of a population of explicit models. The methodology is here applied to a particular case study involving a shallow porous aquifer located in south Italy, showing some peculiar characters. A discussion of the obtained model in the light of the aquifer hydrogeological structure made it possible an hydrogeological based interpretation of the results. The obtained mod-el is consistent with past studies on the same aquifer by other authors based on different methodologies.

Rainfall infiltration can cause a dramatic decrease of suction in unsaturated soils and, consequently, of shear strength, triggering various instability phenomena, such as the slip of steep surface soil layers. Swelling of cracked soils and capillary barrier effects, induced by finegrained soils overlying a more permeable material, can also affect water flow through this type of soil systems. In the past, few studies on infiltration and rainfall-induced landslides considered the simultaneous effects of surface cracks, swelling materials, and/or the capillary barrier phenomenon. To this purpose, this paper presents the results obtained by a dual-permeability model, which simulates water flow through a fractured swelling soil overlying a more permeable soil and focusing on the influence of these phenomena on triggering of landslides. Numerical results show that for high-intensity precipitations, flow through fractures quickly reaches significant depths and the capillary barrier is broken, while soil swelling leads to a uniform narrowing of cracks. On the other hand, for low-intensity precipitations, fracture flow and swelling are limited only to the first 30–50 cm of the topsoil, while cracks almost completely closed. Evaluations of the slope stability show that prolonged low intensity rainfalls might be more dangerous than short high-intensity rains in triggering surface landslides.

Nelle zone orogenetiche le spinte tettoniche del fronte più avanzato della catena creano sollevamenti e deformazioni significative del lato più interno dei depositi di avanfossa. Nel presente lavoro, prendendo spunto da un caso relativo all’Appennino meridionale viene illustrato come al fronte della catena, a seguito di dette spinte si verificano frane ciclopiche da esse indotte, che condizionano sia il reticolo idrografico principale che la pericolosità idraulica e da frana di una vasta area a valle del fronte della catena stessa. Viene inoltre sottolineata l’importanza di riconoscere questo tipo di fenomeni al fine di poter correttamente interpretare le dinamiche fluviali e la suscettibilità da frana delle aree da questi coinvolte. In particolare, è illustrato il caso del versante destro della bassa valle del fiume Biferno, dove è stata riconosciuta e ricostruita una gigantesca frana profonda, coinvolgente un’area di circa 40 km2, che controlla profondamente il percorso del Biferno oltre che quello del suo affluente in sponda destra, il torrente Cigno. In particolare la presenza della grande frana condiziona la pericolosità idraulica di tutta la piana di Termoli (CB), ma anche la suscettività al rischio da frana del fianco sinistro della vallata del Biferno a valle dell’abitato di Guglionesi (CB).

Le argille marnose sovraconsolidate e fessurate come quelle affioranti nella fossa Bradanica si presentano a volte intensamente fessurate e fratturate, il che congiuntamente alla presenza di livelli sabbiosi può dar luogo ad una circolazione delle acque sotterranee che si sviluppa lungo le discontinuità presenti all’interno dell’ammasso argilloso. Il moto dell’acqua lungo queste discontinuità può fra l’altro consentire fenomeni di erosione interna (piping) la cui evoluzione può dare luogo alla formazione di vere e proprie cavità in argille di dimensioni più o meno ampie che possono essere assimilate a fenomeni analoghi a quelli carsici, tanto da poter essere inquadrati fra i fenomeni pseudo carsici. Nel presente lavoro dopo un breve inquadramento sui fenomeni psudo-carsici vengono proposti alcuni approfondimenti di letteratura scientifica sui fenomeni di piping in terreni argillosi e presentati alcuni interessanti casi di evidenze di fenomeni pseudo-carsici in litotipi argillosi della Fossa Bradanica. Viene inoltre evidenziato come questi fenomeni abbiano rilevanza nel condizionare i fenomeni erosivi e la stabilità dei versanti.

The derivation of an alert model for landslide risk management is a paramount problem for those sites which are affected by complex landslides involving strategic infrastructures as well as towns. This is a quite common scenario all over the world and then it is a primary problem for the management of geomorphological risk. Along the Adriatic Coast of south Italy, Petacciato landslide is peculiar, since it showed 11 reactivations between 1924 and 2009. It is a deep-seated landslide, and the history of its reactivations shows that even if generally related to quite abundant rainfall periods, there is no clear correlation between rainfall events and reactivations. For this reason, here, an analysis based on a data-driven evolutionary modeling technique is attempted, in order to identify an alert model based on cumulative rainfall heights. Modeling results are quite interesting and encouraging, since they are able to provide landslide forecasting whereas no false positive are ever returned. This work shows the results of this attempt as well as an analysis of the input to the modeling approach, in order to identify which are those cumulative rainfall heights which are physically sound with respect to the particular landslide.

Digital elevation models processing is a hot topic for identifying the main topographic features of an area. In particular, medium resolution digital elevation models are of particular interest for analysing regional phenomena, like geomorphological evolution and ongoing or past tectonic processes. The key point of these analyses is the extraction of these features from elevation models. In this context, an effective approach is constituted by 2D discrete wavelet transforms. These allow for a multi-scale decomposition, which permits to extract details of digital elevation models, normally not clearly evident looking just at the topography. These details are often associable to anomalies or singularities of the topography, which may be related by a careful geomorphological interpretation to regional tectonic processes or, more in general, to landscape evolution phenomena, i.e. big landslides, erosion, etc.

The tectonic stresses that produceding the uplift of Apennine chain ridge in Southern Italy generated advanced buried thrusts of allochthonous deposits that induced deformations of foredeep deposits. This thrust may cause giant deep-seated landslides at the front of the chain. Starting from a specific case history in low Biferno valley, this work presents how giant deep-seated landslides along the front of the chain may be generated by the thrust of allochthonous nappe of the chain. Besides, the influence that these huge phenomena may have on landslide and flood susceptibility and on natural hazard of the involved area are analyzed. The work presents an interpretations of local morphology and stream network paths of low Biferno valley as consequence of a giant deep-seated landslide affecting the right side of the valley. The proposed interpretation is, supported by numerical geomorphological analyses of the area at stake. It is shown how both the morphologies of the catchments of river Biferno and its tributary Cigno and stream paths are strongly conditioned by this large deep-seated landslide. This landslide deviates the stream paths affecting both the flooding susceptibility of low Biferno valley and landslide susceptibility on the left side of Biferno valley.

This work presents a geomorphometric approach for outlining anomalies of the topographic surface that may be related to geological structures or to geomorphological phenomena. It is based on 2D discrete wavelet transform of digital elevation models. This transform is used to extract singularities of a series of data. This is specifically applied to a digital elevation model, in order to get its detail coefficients and to have evidence about their variations and values. In particular, tThis approach can be helpful for the delineation and identification of landforms singularities as landslides and geological structures. The potential and effectiveness of this approach is shown by an application to a case study about a large deep-seated landslide, located at the central-south front of the Apennine in South Italy.

The present work is focused on investigating the potential role of capillary barriers on the stability of layered soil deposits laying upon high permeability steep slopes. In presence of capillary barrier effects, often possible on a soil stratigraphy characterized by contrasting hydraulic properties (pyroclastics deposit over pumices, silt upon fractured bedrock, silt over sand) failure might originate in less permeable layers, where unsaturated conditions might provide a crucial contribution to stability. Basic ideas and considerations have been drawn from a peculiar case study, the catastrophic landslide occurred in Campania, Southern Italy, on May 1998, which is discussed in this paper from a different perspective. The areal extent of failures’ distribution, their dense concentration at the steeper and higher slopes, the extremely high number of initial failures occurred within a relatively short time span suggest that the intimate cause of the event is related at some extent to the soil state rather than positive pore pressure pulses from water circulation in coarser layers or groundwater rising from bedrock. A widespread loss of soil strength related to saturation can likely explain such phenomena. Capillary barrier effects favour accumulation and lateral distribution of percolating unsaturated flow and possibly divert flowlines downslope, thus leading to localized increases in water content. Diversion of percolating waters facilitate lateral redistribution of soil moisture along the slope with possible further localized saturation, because more permeable layers may act temporarily as barriers and not as drains, as one could expect. Numerical 2-D infiltration models with parameters calibrated versus laboratory data show a relevant influence of capillary barrier effects on infiltration in layered slopes with vertically stratified variations of hydraulic properties and point out significant localized moisture accumulation with possible consequences on slope stability. Landslide initiation phenomena in layered covers might thus be due to the increase in saturation within the least permeable soil layers due to capillary barrier phenomena.

Infinite slope method is the simplest limit equilibrium method for slope stability analysis. It gives reliable results for slides where the longitudinal dimension prevails on the depth of the landslide. Usually results are conservative since not accounting for the effects of the strength along lateral bounds. Starting from an infinite slope analysis accounting the effects of the shear strength along lateral bounds a simplified rectangular cross section, hHere a new expressions of the factor of safety areis introduced, evaluated in a similar way but by an infinite slope analysis accounting for the effects of the shear strength along lateral bounds assuming using an elliptical and a parabolic cross section of the landslide body. The safety factor evaluated in this way can be quite different from those returned by the classic infinite slope model formula, in particular when the width of the landslide is narrow with respect to its depth and the ratio between the width and the depth of the landslide is lower than 5. An interesting implication of the proposed model is that if cohesion is different from zero, there is a “critical depth”, where the safety factor has a minimum value.

Lo studio della dinamica di un acquifero in risposta alle precipitazioni è un problema di fondamentale importanza per la gestione delle risorse idriche sotterranee, specialmente alla luce delle problematiche connesse alle variazioni climatiche che possono incidere sui meccanismi di ricarica della falda. La messa a punto di modelli fisicamente basati atti ad analizzare la dinamica della falda in relazione alle precipitazioni è generalmente non semplice. In tal senso l’utilizzo di tecniche data-driven che forniscano un modello esplicito possono essere un potente strumento sia per lo studio della risposta della falda alle precipitazioni che come strumento di tipo gestionale. In questo lavoro, attraverso la tecnica EPR (Evolutionary Polynomial Regression), è stata modellata la risposta alle precipitazioni di due acquiferi differenti dal punto di vista idrogeologico: uno poroso ed uno carsico fratturato dell’area della Puglia meridionale. La tecnica ha fornito per i due acquiferi modelli molto soddisfacenti e coerenti con le caratteristiche geologiche ed idrogeologiche dei due acquiferi.

The analysis of the dynamic response of a deep karst aquifer to precipitation is a complex problem, due to the structure of the aquifer, which may origin non-linear variations of the groundwater table. However, karst aquifers may be one of the main water resources for those regions characterized by poor presence of shallow water and medium-high permeable soils. This work presents an analysis of the dynamic response of the large aquifer of central Apulia, south Italy, based on a data-driven approach, namely Evolutionary Polynomial Regression. Four wells were monitored, and for each of them about 15 years of monthly average levels are available. In particular, the dynamic response of the aquifer is modelled in terms of prediction of the groundwater levels as function of total monthly precipitations and past measured groundwater levels. A single model, as closed-form equation, is obtained for each well and then these models are compared, highlighting the differences and the similarities among the responses of each well.

La fascia costiera adriatica a nord di Bari è caratterizzata dalla presenza di diversi brevi incisioni morfologiche impostate nei calcari mesozoici del tavolato calcareo murgiano convergenti verso il Mare Adriatico. Esse danno luogo ad uno pseudo reticolo idrografico costituito da ephemeral streams di norma asciutti, nei quali si verifica deflusso solo in occasione di eventi di pioggia eccezionali in termini di intensità e durata, che sottendono bacini di dimensioni relativamente modeste. Nel presente lavoro sono state indagate le principali caratteristiche geomorfologiche di questi bacini e sono state confrontate con quelle di bacini della piana di Brindisi dimensionalmente simili, ma impostati in depositi clastici quaternari. La comparazione delle caratteristiche morfometriche dei due gruppi di bacini ha permesso di sviluppare alcune interessanti riflessioni sulle caratteristiche e la genesi di degli ephemeral stream dell’area costiera nord-barese

The study of the dynamics of groundwater system, as response to rainfall supply, is a hot topic. In fact, physically based model are often not fully satisfactory and difficult to be made up. The use of a data-driven technique returning reliable models, as explicit equations, can be a powerful tool for groundwater management, but also to understand the behavior of the aquifer. Here potentialities and achievements of this kind of methods are presented, in particular focusing on some recent experiences for porous and karst aquifer in Apulia and Basilicata regions.

This work focuses on the impact of the antecedent rainfall as triggering factor of the large landslide occurred in Maierato (south Italy) on February 15, 2010. According to previous studies by Guerricchio et al. (2010) the predisposing factor of the landslide is an ancient deep-seated gravitational slope deformation that significantly affected landforms, drainage networks and infiltration processes of the whole slope where Maierato is located. Here after a brief introduction of the landslide according to the aforementioned study, an hydrological analysis of the rainfall preceding the landslide is presented. The analysis aims at evaluating the exceptionality and some peculiar characters of rainfall, which may be considered among the triggering factors of the landslide.

The identification and quantitative study of important geological discontinuities, like those related to large landslides constitutes a paramount problem, which claims for a careful, detailed and, if possible, quantitatively based geomorphologic analysis. Numerical geomorphic analyses represent an interesting approach to these studies, allowing for a detailed and pretty accurate identification of hidden topographic anomalies that may be related to large landslides or other hidden geological structures. Geomorphic numerical analyses herein presented, are performed on the digital elevation model, based on the 2D discrete wavelet transform. This analysis is applied to a case study related to the middle-south Apennine at the front of the Apennine, whereas a really large deep-seated large landslide has been previously identified on the base of different geomorphic analysis. Finally, the analysis emphasizes some peculiar aspect of the buried front of the Apennine, which can potentially bias the landslide.

The study of aquifers dynamics is a fundamental issue for the analysis of groundwater resources. However, the modeling of aquifer dynamics by means of physically based models is geneally not simple and cheap since a lot of information is necessary in order to define the model. For this reason the use of data-driven modeling approaches, able to return explicit models starting from measured reasonably low cost data, could be a solution to this issue. Thus, this work introduces the use of an evolutionary modeling technique, namely Evolutionary Polynomial Regression (EPR), aimed at the prediction of water table levels for two aquifers located in the same area of south east of Italy. These aquifers are hydrogeologically different, even if located in the same area. The earlier is a surficial porous aquifer, while the latter is a coastal karst aquifer. Even if subject to the same climate conditions, they show different hydrogeological behaviours, in term of different dynamics and responses to rainfall. EPR is used herein to predict groundwater levels for both the aquifers as well as returning equation structures which are consistent with their different dynamics. The obtained results show how EPR is able to correctly interpretate different hydrogeological situations.

The analysis of the dynamic response of a karst aquifer to precipitations, due to its complex structure, is not simple, given the non-linear response of the groundwater table. This work presents the analysis of the dynamic response of Murgia large karst aquifer, central Apulia, south Italy, based on a data-driven approach, namely Evolutionary Polynomial Regression. This is applied to the monthly average levels measured in three wells for about 15 years. Groundwater levels are predicted as a function of the previous groundwater levels and monthly rainfall data. Results show the complex behavior of this aquifer.

The residual shear strength as operative strength along the shear surface is commonly used for analyzing the stability of reactivated landslides. On this base, it is not possible to have brittle failure or progressive failure mechanisms. In fact, these kinds of phenomena claim for a recovery of strength along the shear surface, which is due to ageing effects during the quiescence time. Several tests on clay samples were performed using Bromhead ring shear apparatus to verify the presence of shear strength recovery. Tests showed that recovery of strength are present along the shear surface. Moreover, they proved the stress-stain behavior is characterized by a brittle failure after that the strength, along the shear surface, falls again to the residual value.