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Rainfall-induced landslides are a disastrous natural hazard causing loss of life and significant damage to infrastructure, farmland and housing. Hydromechanical models are one way to assess the slope stability and to predict critical combinations of groundwater levels, soil water content and precipitation. However, hydromechanical models for slope stability evaluation require knowledge about mechanical and hydraulic parameters of the soils, lithostratigraphy and morphology. In this work, we present a multi-method approach of site characterization and investigation in combination with a hydromechanical model for a landslide-prone hillslope near Bonn, Germany. The field investigation was used to construct a three-dimensional slope model with major geological units derived from drilling and refraction seismic surveys. Mechanical and hydraulic soil parameters were obtained from previously published values for the study site based on laboratory analysis. Water dynamics were monitored through geoelectrical monitoring, a soil water content sensor network and groundwater stations. Historical data were used for calibration and validation of the hydromechanical model. The well-constrained model was then used to calculate potentially hazardous precipitation events to derive critical thresholds for monitored variables, such as soil water content and precipitation. This work introduces a potential workflow to improve numerical slope stability analysis through multiple data sources from field investigations and outlines the usage of such a system with respect to a site-specific early-warning system.

O Platô da Ramada (PR) é uma das áreas do Escudo Sul-rio-grandense(ESRG) submetidas a uma intensa atividade vulcânica e plutônica (574-549 Ma) ocorrida durante o Ediacarano, vinculado aos estágios finais e pós-colisionais do ciclo orogênico Brasiliano-Pan-africano. Os dados geofísicos apresentados nesta dissertação foram obtidosa partir de levantamentos radiométricos, magnéticos e gravimétricos, processados e interpretados em conjunto com as informações geológicas disponíveis. Os dados radiométricos mostram o enriquecimento de K, Th e U na porção central do platô, o que reforça o caráter de alta sílica das rochas riolíticas e piroclásticas da Formação Acampamento Velho. Os dados magnéticos permitiram o reconhecimento dos principais lineamentos magnéticos, os quais coincidem com os lineamentos geológicos mapeados em campo, sugerindo um forte controle estrutural sobre a dinâmica de posicionamento dos diques e intrusões. Os dados gravimétricos permitiram,através do mapa de Anomalia Bouger, a identificação de uma sériede intrusões agregadas nas porções norte e sul do Complexo Granítico Ramada, caracterizadas respectivamente por altos e baixos valores de anomalia Bouger, sendo a intrusão isolada na porção sul do Granito Ramada uma importante feição identificada. Os métodos de estimativa de profundidade utilizados foram a deconvolução de Euler e a análise do espectro de potência associado aos dados magnéticos e gravimétricos que indicaram o predomínio de fontes anômalas localizadas em porções rasas a intermediárias. Os valores negativos da anomalia Bouger sobre o domínio de anomalias negativas na porção sul do Granito Ramada, juntamente com a proximidade espacial entre rochas vulcânicas e plutônicas e a correspondência geoquímica representada pelo enriquecimento proporcional dos três radioelementos considerados, são os aspectos que reforçam as evidências para a provável ocorrência de um sistema vulcânico-plutônico félsico no Platô da Ramada, com indícios do desenvolvimento de um sistema de subsidência de caldeira na região. The Ramada Plateau is one of the areas of the Sul-rio-grandense shield subjected to intense plutonic-volcanic activity in the Ediacaran age (574-549 My), during the post-collisional stages of the Brazilian orogenic cycle. The geophysical data presented in this study comprise the radiometric, magnetic and gravimetric data of the Ramada Plateau, processed and interpreted jointly with the geological information. The enrichment of the three radioelements, to wit, K, Th and U, in the central portion of the plateau, reinforces the high silica character of the rhyolitic and pyroclastic rocks of the Acampamento Velho Formation, corroborating with the geochemical correspondence between volcanic and plutonic rocks. The magnetic data have allowed us to recognize the main magnetic lineaments of the area, which coincide with the geological lineaments mapped in fieldwork and suggest a strong structural control on the emplacement dynamics of the dikes and intrusions. The gravimetric data have been extremely useful for the identification of the isolated intrusion adjacent to a zone of negative Bouger values in the southern portion of the Ramada Granite. The depth estimation methods used were the Eulerdeconvolution and radially average power spectrum, which indicated predominantly shallow and intermediate depth. Thenegative gravimetric value in the negative gravimetric domain, jointly with the spatial proximity between the volcanic and plutonic rocks and the geochemical correspondence, represented by the enrichment of the three radioelements, are the aspects that better serve as evidence for the likely occurrence ofa volcanic-plutonic felsic system in the Ramada Plateau with clues of a caldera subsidence system.

La caracterización de la fábrica constructiva de edificaciones previa a su restauración o evaluación de estabilidad requiere estudios históricos previos y análisis del estilo constructivo del momento de construcción. En ocasiones dicha información es limitada o requiere ser contrastada por métodos de caracterización directa. En este trabajo se aborda el análisis de la fachada principal de las Escuelas Mayores de Salamanca (“Fachada Rica”) a través de la caracterización geofísica por medio de georradar, de 3 sondeos horizontales y los resultados obtenidos del análisis constructivo con criterios histórico-artísticos. Los resultados obtenidos permiten identificar la correlación entre las unidades geofísicas identificadas en los sondeos, y evaluar la variabilidad lateral de dichas unidades, Constructive fabric characterization previous to restauration is required for the design and stability analysis. These studies include the integration of historical data and knowledge of building style at the construction period. Sometimes this information is limited or requires to be contrasted with present-day construction features. In this work the Escuelas Mayores de Salamanca main façade (“ Fachada Rica ”) is evaluated through the integration of three horizontal boreholes and the obtained results from the geophysical characterization by means of GPR and considering the artistic-historical construction criteria since its construction moment. The obtained results permit to identify the correlation between the defined geophysical units and the layers identified in boreholes and to evaluate the lateral correlation of these boreholes along the whole analyzed façade

Resumen En este trabajo se presenta la metodología y resultados de la caracterización geofísica realizada en un intervalo de la Formación Porquero de edad Mioceno, definido informalmente como FP-H3 (Formación Porquero – H3), dentro de un área Piloto ubicada en la Cuenca del Valle Inferior de Magdalena, Colombia. Se busca la caracterización y delineación de un yacimiento de gas mediante la integración de los resultados de la inversión sísmica y la información de pozos (petrofísica y física de rocas). El yacimiento de gas caracterizado corresponde a un importante número de láminas de areniscas intercaladas con lutitas. La resolución vertical de los registros resulta insuficiente para resolver este arreglo laminar. Sin embargo, debido a que estas alternancias laminares se encuentran agrupadas en espesores mayores y embebidos en una espesa sección lutítica, es posible diferenciar mediante la información sísmica y de pozo, esta disposición litológica. Estas características de reservorio llevaron a desarrollar un análisis geofísico especializado de diferentes propiedades elásticas calculadas a partir de registros de pozo y derivadas del modelo de inversión sísmica. Con el fin de analizar en mayor detalle el intervalo objetivo (FP-H3), se utilizaron los resultados del análisis de física de rocas y las propiedades obtenidas del modelo de inversión sísmica para construir un modelo de geocuerpos predictivo en diferentes subniveles de FP-H3 dentro del volumen que abarca la sísmica 3D. Posteriormente el modelo fue poblado con las propiedades Lambda-Rho (λρ), Mu-Rho (µρ) y fragilidad, las cuales fueron seleccionadas como las mejores para la caracterización del yacimiento. Debido a la baja permeabilidad y pobre conectividad del yacimiento, existe la necesidad de estimularlo con fracturamiento hidráulico, por tal motivo, la estimación y análisis de la fragilidad a partir de las propiedades elásticas resultantes de la inversión sísmica fue determinante para la caracterización del reservorio, permitiendo predecir la distribución y calidad de intervalos fracturables en el área de estudio. Abstract. This paper presents the methodology and results of a geophysical characterization performed in the Porquero Formation interval informally defined as FP-H3 (Porquero Formation – H3), within a pilot area located in the Lower Magdalena Basin, Colombia. The objective of the study is to characterize and delineate a gas field by integrating results from the seismic inversion and well information (petrophysics and rock physics). The gas reservoir characterized is formed by numerous laminar sandstones interbedded with shales. Vertical resolution of logs is insufficient to solve this laminar arrangement. However, because these laminar alternations are grouped in greater thicknesses and embedded in massive shales, it is possible to differentiate this lithologic of arrangement with seismic data and well logs. These characteristics of reservoir led to develop a specialized geophysical analysis on the different elastic properties calculated from logs and derived from seismic inversion model. In order to further analyze the target interval (FP-H3), the results of rock physics analysis and the properties obtained from the seismic inversion model were used to build a predictive geobody model in different sublevels of FP-H3 within the 3D seismic. Subsequently the model was populated with Lambda-Rho (λρ), Mu-Rho (μρ) and brittleness properties which showed to be the best to characterize the reservoir. The low permeability and poorly connected sand reservoir require hydraulic stimulation, therefore, estimation and analysis of brittleness from the elastic properties resulting from seismic inversion was decisive for reservoir characterization, allowing to predict the distribution and quality of intervals to be frac-stimulated in the study area. Maestría

The paper shows recurrence plots obtained from time series of the level variations of four lakes in Africa (Nasser, Tana, Chad and Kainji). The data, coming from remote sensing, are provided by the United States Department of Agriculture. The recurrence plots allow a good visual comparison of the behaviours of local drainage basins., Comment: Keywords: Recurrence plots, Geophysics, Chaos, Attractors, Climate

International audience; Thermal stress can result in significant changes in the mechanical and transport properties of building materials, especially in terms of cracking. Three building materials were studied: two concretes, a siliceous and a calcareous one, and a natural calcareous rock, the Tuffeau. The samples were subjected to thermal shock, repetitive heating-cooling cycles, and high temperature heating in order to analyze the effects of maximum temperature, cooling rate, and repetitive heating on the three materials. The induced cracks were then characterized by physical and hydraulic measurements, namely elastic wave velocities, porosity and effective thermal conductivity. Elastic wave velocities were used to determine crack density while effective thermal conductivity was used to determine crack connectivity. Cracks were also quantitatively described through direct microstructural observations using scanning electron microscopy. Results show the effectiveness of the different protocols in inducing cracks. Unexpectedly, repetitive heating-cooling cycles caused the most significant sample damage, whatever the sample. A second main result is based on the comparison of the different materials. It was found that the behavior of the two concretes was very similar: the stronger the thermal treatment, the more the crack density and connectivity increased, albeit with a slight difference in that the siliceous concrete appeared to be less resistant to sharp thermal variations. This is interpreted as being linked to microstructural effects: in the siliceous concrete, we observed cracks that nucleated around and inside grains, but not in the calcareous concrete. Lastly, the behavior of the Tuffeau limestone was different from that of the concretes: when crack density increased, the crack connectivity and the porosity both decreased. This different behavior is interpreted in the light of microstructural observations of the crack apertures: the thermally induced cracks in Tuffeau are too small to influence the effective thermal connectivity measurement and to allow fluid flow during the porosity measurement, whereas in the concretes, cracks were observed to be much more open. As an outlook, we discuss a possible equivalent test to the normalized fire protocol, performed at high temperature, to test the fire resistance of materials.

The Alimini water system, located in south eastern part of Italy, named Salento peninsula, is constituted from two connected coastal lakes, Alimini Piccolo and Alimini Grande. Specifically, Alimini Piccolo is a small freshwater body, directly fed by rainfall and by shallow porous aquifer through of several springs. From '50s Alimini Piccolo provides the surrounding area with water for agriculture and domestic use. In June 2013, IRSA-CNR started a study concerning the quali-quantitative characterization of the hydrogeological system feeding the Alimini Piccolo, in order to investigate the potential for additional exploiting of the lake as a resource for drinking water. For the purpose, a monitoring system has been set up for an entire hydrological year. Continuous measurements of water level, electrical conductivity and temperature, such as quantitative and qualitative monitoring monthly campaigns both in groundwater and in the lake have been carried out. In order to support the above mentioned surveys, Electrical Resistivity Tomography (ERT) has been carried out to identify geological structures and hydrogeological features, to better understand the system feeding the Alimini Piccolo and to set the boundary conditions of the hydrological model useful to represent the water balance of the lake.

The managing and monitoring of natural and artificial river levees are crucial in order to reduce the hydrological risk. As these hydraulic structures are very extensive, the typically applied techniques (e.g. geotechnical soundings and visual inspections) provide only punctual information that are generally focused on areas already recognized as troublesome. To overcome these well-known issues, non-invasive and cost-effective geophysical measurements have been proposed (and used) to supply spatially extensive data that should be integrated with direct investigations. Therefore, in this paper we present the joint use of multichannel analysis of surface waves (MASW), electrical resistivity tomography (ERT), and ground penetrating radar (GPR) to characterize a reconstructed river embankment (made of concrete and tout-venant) prone to serious leakages. We compare common lengthwise ERT profiles, performed from the levee crest, with cross-embankment and cross-river profiles, showing how relying only on the first type of surveys may lead to misinterpretations. Furthermore, we take advantage of a land-streamer for the MASW surveys and of a trans-illumination approach to improve the GPR application. The comparison between geophysical and geotechnical data helps identify the spatial extent of the volume actually invaded by grouting injections, which appears as a highly electrically conductive mean. The lack of homogeneity within this domain, highlighted by the cross-embankment ERT profiles, can be related to the seepage phenomena affecting this artificial levee. Therefore, this case study demonstrates the effectiveness of combining direct and non-invasive investigations for the characterization of river embankments.

Degrading or thawing permafrost has been identified as being an issue of national importance with respect to its potential for causing severe damages or even loss of lives in densely populated Alpine regions due to climate change (Gruber et al. 2004; Gruber and Haeberli 2007). On this basis, a joint study was initiated by the Safe Mountain Foundation (Fondazione Montagna Sicura, Cormayeur, Italy) and some universities to investigate variations in geotechnical behaviour of the Alpine permafrost caused by changes in temperature. Permafrost is found in the Alpine regions at elevations higher than 2,500 m above sea level, depending on the location and exposure of the slope. Its mechanical features are determined by the combined effect of ice and soil particles. The water content can have an important influence on the shear resistance of the frozen soil: if the water content is low, the ice will not be able to include the soil particles. However, if it is very high, the resistance will be determined above all by the ice itself (Andresland 1987). Temperature is another driving factor that can influence the mechanical behaviour of ice (Fish and Zaretsky 1997). On this basis, this work concentrates on analysing the geotechnical and geophysical behaviour of the dispersed moraine deposits found in Alpine areas, which have been subjected to different climatic conditions due to the effect of high temperatures. The work concentrates on the geotechnical and geophysical characterization of two different glacial deposits present in the Aosta Valley region; the first one generated by the Tsanteleina glacier (Rhemes Valley, 2,690 m a.s.l.), and the second one surrounding the Blu lake (Ayas Valley, 2,214 m a.s.l.). The characterization was carried out at different scales: laboratory-scale analysis using representative granular materials and field in situ investigations, geotechnical and geophysical testing. The geotechnical measurements were performed using photographic dimension analysis of the deposit, coupled with seismic and electrical surveys. Specimens were collected, remolded, saturated, and kept in a cooler in the laboratory. The specimens were later subjected to laboratory tests to evaluate the geomechanical strength properties of the materials using (mono-axial compressive strength and Young modulus) and geophysical (P and S wave velocities) behaviour of this kind of soils are affected by temperature variations under 0 °C (−35/−5 °C).

The paper reports about the in-situ and laboratory tests executed in the aftermath of the April 6, 2009 L’Aquila earthquake, aimed at contributing to the definition of geotechnical models for site response analyses in the Aterno valley. The investigation started immediately after the earthquake and was entrusted by the Civil Protection Department to different public institutions and private companies; the experimental activities here reported were coordinated by the Italian Geotechnical Society. In the paper, after briefly depicting the geological setting of the L’Aquila basin and the Aterno river valley, an overview of their subsoil conditions is given, based on the geotechnical tests executed before the 2009 earthquake. Thereafter, the specific investigations planned for the characterization of reconstruction sites and seismic microzonation are widely described. The in situ tests consisted of seismic dilatometer and multi-receiver surface wave tests; the resulting shear wave velocity profiles were compared each other, and against independent Down-Hole tests and ambient noise measurements. The laboratory investigation included cyclic/dynamic simple/torsional shear tests on undisturbed samples. The results, summarized in terms of variation of stiffness and damping with shear strain, highlighted some peculiar properties of the soils in the Aterno valley, which could be related to their index properties.

Um estudo multidisciplinar, envolvendo dados geofísicos, geológicos, hidrogeológicos e hidroquímicos, foi desenvolvido para a caracterização geoambiental da região do cemitério Bom Jardim em Fortaleza, Ceará - Brasil. O reconhecimento do meio rochoso foi efetuado com base em inúmeras sondagens elétricas verticais (SEV's) e seções GPR e EM-34, além de furos de sondagem com análises composicionais, granulométricas e de condutividade hidráulica das amostras de solo coletadas. A caracterização hidrogeológica da região do cemitério foi baseada na assinatura geofísica do substrato rochoso, nos dados topográficos da área, medidas dos parâmetros hidrogeológicos e análises físico-químicas da água subterrânea, obtidos em poços de monitoramento. A qualidade da água subterrânea local foi avaliada através de análises físico-químicas e microbiológicas para indicadores de contaminação por necro-chorume. Amostragens periódicas permitiram avaliar as influências sazonais nos parâmetros hidrogeológicos do aqüífero ao longo de um ciclo hidrológico completo. Concomitantemente, pretendia-se obter as assinaturas geofísicas de possíveis plumas de contaminação por necro-chorume. Contudo, altos teores de sais dissolvidos e microrganismos estão presentes em todo o aqüífero livre da região, mascarando possíveis contrastes de propriedades elétricas ou eletromagnéticas entre as áreas de maior concentração de necro-chorume na necrópole e nas regiões circunvizinhas. A multidisciplinary study, involving geophysical, geological, hydrogeological and hydrochemical data, was developed to the geoenvironmental characterization of the Bom Jardim cemetery in Fortaleza, Ceará State - Brazil. The characterization of the subsurface environment has been carried out based on several vertical electric sounding, GPR and EM-34 sections, compositional, granulometric and hydraulic conductivity analyses of soil samples collected in boreholes. The hydro-geological evaluation of the cemetery site was based on the subsurface geophysical signature, topographical data, hydrogeological parameters and physical-chemical analyses of the groundwater, obtained in monitoring wells. The local groundwater quality was evaluated through physical-chemical and microbiological analyses to investigate the groundwater contamination by the leachate from the corpse decomposition. Periodic samplings allowed evaluating the seasonal influences in the hydrogeological parameters of the aquifer along a complete water cycle. This study also attempted to identify the possible geophysical signatures of contamination plumes into the cemetery site. However, high concentration of dissolved elements and organic compounds are present in the unconfined aquifer of the whole studied area, originate from residential septic tanks. This pollution source probably masks possible contrasts of electric or electromagnetic properties between the supposed contamination plume into the necropolis and the surrounding vicinity.

Since abandoned waste landfills are characterised by strong heterogeneities of the filling and, in some cases, the waste is irregularly distributed and mixed with soil, it is very dificult to plan a priori a standard investigation procedure able to supply the necessary information to site assessment.

The characterization of contaminated sites requires that direct investigations be supplemented with a suitable set of less-invasive, and more extensive, measurements. A combination of geophysical methods and direct push penetrometric techniques has been recently proposed as the backbone of site characterization within the EU FP7 project ModelPROBE. Here we present the first results of the investigations conducted at a field site in Trecate (NW Italy) which was affected in 1994 by crude oil contamination from a well blowout. The investigations include surface GPR, ERT, IP, SIP and SP surveys, together with direct push sampling and EC logs and limited cross-hole measurements. Many of the geophysical measurements have been conducted in time-lapse mode in order to separate static and dynamic signals, the latter particularly linked to strong seasonal changes in water table elevations. The goal is to identify (a) the structural characteristics that controlled the contaminant penetration into the subsurface and its current possible movements, and (b) assess possible correlation between measured geophysical properties and contamination levels and/or biodegradation of contaminants. Our preliminary results help provide a reasonable description of the contaminant infiltration mechanisms into the subsurface, while further analyses are necessary to establish a direct link with contamination and biodegradation.