On the Combination of Remote Sensing and Geophysical Methods for the Digitalization of the San Lázaro Middle Paleolithic Rock Shelter (Segovia, Central Iberia, Spain)

This paper is focused on the Middle Paleolithic rock shelter called “Abrigo de San Lázaro”, placed in the Eresma River valley (Segovia, Spain). In this area, a multisource geomatic approach is used. On the one hand, the external envelope of the shelter has been digitalized by the means of an efficient combination between aerial photogrammetry and laser scanning (static and mobile). On the other hand, the ground penetrating radar and the electric tomography were used with the aim of evaluating the inner disposition of the shelter. The combination of both digitalization (external and internal) has allowed for improving the knowledge of the site characteristics that, in turn, will facilitate the future excavation works. The results of these studies allow archaeologists to know new data for a better understanding of the site formation (geology of the site, sedimentary potential, rock shelter dimensions, etc.) and the events that took place in it (knowing its historical evolution, especially the interaction between man and the environment). Additionally, the information obtained from these studies is very useful to plan future excavation works on the site

The Differential Slow Moving Dynamic of a Complex Landslide: Multi-sensor Monitoring

World Landslide Forum (4º. 2017. Liubliana, Eslovenia)Monitoring is essential to understand the mechanics of landslides, and predict their behavior in time and space. In this work we discuss the performance of multi-sensor monitoring techniques applied to measure the kinematics and the landslide hydrology of Portalet landslide complex, which is located in the SW-facing slopes of Petrasos peak at the border between Spain and France. In the summer 2004, the excavation of a parking lot at the foot of the slides triggered a secondary failure in the lower part of the slope, accelerating the dynamic of the landslide complex. The deployed hydro-meteorological network has been useful to understand that the greatest infiltration in the moving mass is produced in spring due to the combination of snow melt and seasonal rainfall. Landslide surface kinematics measured with differential GPS (D-GPS) were useful to measure the slower (<10 cm/year) and faster (20–30 cm/year) dynamic of the landslide complex. Advanced DInSAR was useful to monitor the slower ground displacements from long datasets of SAR images, providing a wider spatial coverage and measurement point density than the D-GPS. In addition, the NL-InSAR processing strategy was applied to monitor the faster motion using short datasets of TerraSAR-X images excluding the snow cover period. The installed horizontal extensometers were useful to study the extension of the head scarp and its relationship with landslide hydrology, which is affected by the retrogressive effect of the landslide due to the loss of lateral confining pressure. Finally, an inclinometric robot system (AIS) was the only technique capable of detecting 5–6 time faster motion after the snow melt, since it provides daily measurements with high accuracy even during the snow cover period. These data, even if expensive to gather, are necessary to improve the hydro-mechanical modeling of large slow landslides, such as those already proposed for Portalet landslide complex.Geohazard InSAR Laboratory and Modelling Group, Instituto Geológico y Minero de España, EspañaNational Research Council, ItaliaEscuela de Minas, Univesidad de Oviedo, EspañaDares Technology, EspañaAltamira Information, EspañaPeer reviewe

Multiscale Analysis of Geo-Hazards Affecting the Alhambra Cultural Heritage

[EN] This paper presents a multiscale methodology to perform successful geo-hazards assessment in the context of Cultural Heritage. The methodology, defined in the European PROTHEGO project, has been applied to the Alhambra case study. Alhambra is an important Word Heritage site located in Andalusia, Spain. The site is prone to suffer flood, earthquake and landslide phenomena. The proposed multiscale methodology leans on new remote monitoring and modelling technics that not entail aesthetic and functional impacts on the site. For large-scale monitoring, satellite remote sensing technology enables to detect and characterize spatiotemporal ground and structure deformation as a whole, with up to millimeter precision. For very local phenomena analysis, small-scale monitoring based on Terrestrial Laser Scanner and airborne drone digital photogrammetry surveys enables to detect erosion processes that affect the slopes of the citadel. Furthermore, numerical modelling enables geo-mechanical instabilities to be quantified at different scales. Large-scale modelling shows that the most dangerous slope is located at the San Pedro cliff site. Small-scale stability analysis in the San Pedro cliff shows that a slope failure, triggered by a possible earthquake scenario, could reach the wall foundations of the Alhambra citadel located 22 m behind it. Finally, very detailed small-scale modelling, using very precise digital elevation models, enables to track local instabilities and erosion phenomena. Such a multiscale, interdisciplinary approach is the most effective way to identify, assess and monitor risks, strengthening disaster preparedness at heritage property.The research leading to these results has been supported by the PROTHEGO Project (Protection of European Cultural Heritage from Geo-hazards), funded through the framework of the Joint Programming Initiative on Cultural Heritage and Global Change (JPICH), and under ERA-NET Plus and the Seventh Framework Program (FP7) of the European CommissionPeer reviewe

Landslide databases in the Geological Surveys of Europe

Acceso electrónico sólo desde el IGMELandslides are one of the most widespread geohazards in Europe, producing significant social and economic impacts. Rapid population growth in urban areas throughout many countries in Europe and extreme climatic scenarios can considerably increase landslide risk in the near future. Variability exists between European countries in both the statutory treatment of landslide risk and the use of official assessment guidelines. This suggests that a European Landslides Directive that provides a common legal framework for dealing with landslides is necessary. With this long-term goal in mind, this work analyzes the landslide databases from the Geological Surveys of Europe focusing on their interoperability and completeness. The same landslide classification could be used for the 849,543 landslide records from the Geological Surveys, from which 36% are slides, 10% are falls, 20% are flows, 11% are complex slides, and 24% either remain unclassified or correspond to another typology. Most of them are mapped with the same symbol at a scale of 1:25,000 or greater, providing the necessary information to elaborate European-scale susceptibility maps for each landslide type. A landslide density map was produced for the available records from the Geological Surveys (LANDEN map) showing, for the first time, 210,544 km2 landslide-prone areas and 23,681 administrative areas where the Geological Surveys from Europe have recorded landslides. The comparison of this map with the European landslide susceptibility map (ELSUS 1000 v1) is successful for most of the territory (69.7%) showing certain variability between countries. This comparison also permitted the identification of 0.98 Mkm2 (28.9%) of landslide-susceptible areas without records from the Geological Surveys, which have been used to evaluate the landslide database completeness. The estimated completeness of the landslide databases (LDBs) from the Geological Surveys is 17%, varying between 1 and 55%. This variability is due to the different landslide strategies adopted by each country. In some of them, landslide mapping is systematic; others only record damaging landslides, whereas in others, landslide maps are only available for certain regions or local areas. Moreover, in most of the countries, LDBs from the Geological Surveys co-exist with others owned by a variety of public institutions producing LDBs at variable scales and formats. Hence, a greater coordination effort should be made by all the institutions working in landslide mapping to increase data integration and harmonization.Earth Observation and Geohazards Expert Group (EOEG), EuroGeoSurveys, the Geological Surveys of Europe, BélgicaGeohazards InSAR Laboratory and Modeling Group, Instituto Geológico y Minero de España, EspañaRisk and Prevention Division, Bureau de Recherches Géologiques et Minières, FranciaEngineering Geology Department, Institute of Geology and Mineral Exploration, GreciaGeoHazard team, Geological Institute of Romania, RumaníaGeological Survey of Slovenia, EsloveniaCroatian Geological Survey, CroaciaItalian Institute for Environmental Protection and Research, Geological Survey of Italy, ItaliaSwiss Federal Office for the Environment, SuizaGeological Survey of Austria, AustriaPolish Geological Institute, National Research Institute, PoloniaGeological Survey of Ireland, IrlandaCzech Geological Survey, República ChecaFederal Institute for Geosciences and Natural Resources, AlemaniaGeological Survey of Norway, NoruegaCyprus Geological Survey, ChipreGeological Survey of Sweden, SueciaInstitut Cartogràfic i Geològic de Catalunya, EspañaBritish Geological Survey, Reino UnidoGeological Survey of Slovakia, EslovaquiaGeological Survey of Lithuania, LituaniaFederalni zavod za geologiju, Bosnia y HerzegovinaGeological Survey of Estonia, EstoniaLaboratório Nacional de Energia e Geologia, PortugalGeological Survey of Hungary, HungríaNorwegian Water and energy Directorate of Norway, Norueg

Systematic Collaborative Reanalysis of Genomic Data Improves Diagnostic Yield in Neurologic Rare Diseases

Altres ajuts: Generalitat de Catalunya, Departament de Salut; Generalitat de Catalunya, Departament d'Empresa i Coneixement i CERCA Program; Ministerio de Ciencia e Innovación; Instituto Nacional de Bioinformática; ELIXIR Implementation Studies (CNAG-CRG); Centro de Investigaciones Biomédicas en Red de Enfermedades Raras; Centro de Excelencia Severo Ochoa; European Regional Development Fund (FEDER).Many patients experiencing a rare disease remain undiagnosed even after genomic testing. Reanalysis of existing genomic data has shown to increase diagnostic yield, although there are few systematic and comprehensive reanalysis efforts that enable collaborative interpretation and future reinterpretation. The Undiagnosed Rare Disease Program of Catalonia project collated previously inconclusive good quality genomic data (panels, exomes, and genomes) and standardized phenotypic profiles from 323 families (543 individuals) with a neurologic rare disease. The data were reanalyzed systematically to identify relatedness, runs of homozygosity, consanguinity, single-nucleotide variants, insertions and deletions, and copy number variants. Data were shared and collaboratively interpreted within the consortium through a customized Genome-Phenome Analysis Platform, which also enables future data reinterpretation. Reanalysis of existing genomic data provided a diagnosis for 20.7% of the patients, including 1.8% diagnosed after the generation of additional genomic data to identify a second pathogenic heterozygous variant. Diagnostic rate was significantly higher for family-based exome/genome reanalysis compared with singleton panels. Most new diagnoses were attributable to recent gene-disease associations (50.8%), additional or improved bioinformatic analysis (19.7%), and standardized phenotyping data integrated within the Undiagnosed Rare Disease Program of Catalonia Genome-Phenome Analysis Platform functionalities (18%)

Detección, estudio y modelización de movimientos de ladera muy lentos para el desarrollo de herramientas de gestión del territorio

Tesis doctoral por el sistema de compendio de publicacionesLas particulares características geográficas, geológicas y climáticas de la parte alta del Valle de Tena (Huesca), condicionan la presencia de un gran número de grandes deslizamientos antiguos que actualmente se encuentran activos, con movimientos del orden de mm a cm al año. Durante siglos, las actividades agrícolas y ganaderas en este valle pirenaico convivieron sin problema con estos procesos naturales, pero en los últimos años, el desarrollo del turismo y la estación de esquí de Formigal están siendo claves en el aumento del riesgo. Hoy en día, la mejora de técnicas como la interferometría de imágenes radar satélite (DInSAR) está abriendo una ventana al estudio de los deslizamientos lentos. En esta investigación se ha desarrollado y validado un método que integra técnicas clásicas de cartografía, reconocimiento y auscultación de deslizamientos, con técnicas de monitorización DInSAR y DGPS y modelización numérica avanzadas. A escala regional, se ha investigado el uso conjunto de técnicas convencionales (DInSAR) y avanzadas (PSI o A-DInSAR) para cartografiar y monitorizar los deslizamientos lentos del valle. Los resultados muestran que la técnica PSI multi-banda (C, X y L) ofrece una gran capacidad de detección de deslizamientos activos mientras que los interferogramas DInSAR de las imágenes del satélite ALOS PALSAR permiten detectar movimientos más rápidos (hasta 145 cm/año). La integración de todos los datos de velocidad y su comparación con los daños observados en las carreteras y en la estación de esquí, han permitido elaborar mapas inventario de deslizamientos clasificados según su capacidad potencial de producir daños, lo que constituye un instrumento muy útil en ordenación territorial. A nivel local, la técnica PSI ha permitido descubrir diferentes patrones de movimiento dentro de las masas movidas. Se ha comprobado que los deslizamientos analizados sufren aceleraciones que muestran un carácter estacional. Su comparación con datos meteorológicos ha permitido formular la hipótesis de que, aparte de la acción humana, el principal factor responsable de la reactivación y/o aceleración de los grandes deslizamientos en Tena es la variación del nivel de las aguas subterráneas, que depende de las precipitaciones y de la fusión de nieve. Para validarla se ha estudiado en detalle el deslizamiento de El Portalet, un gran deslizamiento complejo muy lento que, tras la excavación realizada en 2004 para construir un aparcamiento en su pie, experimentó movimientos que obligaron a ejecutar obras de estabilización. Se han definido los modelos geomecánico e hidrogeológico de la ladera y la morfología y cinemática del deslizamiento integrando los resultados obtenidos en reconocimientos geomorfológicos, geofísicos (tomografías sísmica y eléctrica), geotécnicos (sondeos y ensayos in situ), hidrogeológicos (piezómetros y ensayos de permeabilidad) y los datos de auscultación de movimientos superficiales (extensómetros, DInSAR, DGPS) y profundos (inclinómetros). Con esta información se han implementado, calibrado y validado modelos matemáticos que permitieron inferir las causas y reproducir los movimientos observados. Se ha calculado la probabilidad de rotura de la ladera mediante el método de equilibrio límite introduciendo distribuciones estadísticas de los parámetros geotécnicos para distintos escenarios, lo que ha permitido confirmar que la causa de la reactivación del deslizamiento fue la excavación de su pie. Por último, se ha elaborado un modelo 2D de elementos finitos que ha reproducido su comportamiento cinemático en el tiempo proporcionando con éxito predicciones a corto y medio plazo durante las etapas de fluencia primaria y secundaria. El modelo viscoplástico ha reproducido la relación de fluencia constante medida durante las campañas de monitorización, y la formulación acoplada u-pw ha permitido simular la aceleración y desaceleración del deslizamiento con las variaciones del nivel freático, confirmándose así la hipótesis planteada

2D viscoplastic finite element modelling of slow landslides: the Portalet case study (Spain)

This paper proposes a hydro-geomechanical finite element model to reproduce the kinematic behaviour of large slow landslides. The interaction between solid skeleton and pore fluids is modelled with a time dependent u–pw formulation and a groundwater model that takes into account recorded daily rainfall intensity. A viscoplastic constitutive model based on Perzyna’s theory is applied to reproduce soil viscous behaviour and the delayed creep deformation. The proposed model is applied to Portalet landslide (Central Spanish Pyrenees). This is an active paleo-landslide that has been reactivated by the construction of a parking area at the toe of the slope. The stability analysis reveals that, after the constructive solutions were undertaken, the slope is in a limit equilibrium situation. Nevertheless, time-dependent analysis reproduces the nearly constant strain rate (secondary creep) and the acceleration/deceleration of the moving mass due to hydrological changes. Overall, the model reproduces a 2-m displacement in the past 8 years that coincides with in situ monitoring data. The proposed model is useful for short- and midterm predictions of secondary creep. However, long-time predictions remain uncertain, stability depends strongly on the position of the water table depth and new failures during tertiary creep due to soil temporal microstructural degradation are difficult to calibrateGeohazards InSAR Laboratory and Modeling Group, Instituto Geológico y Minero de España, EspañaMathematical Modelling Engineering Group, Universidad Politécnica de Madrid, EspañaUnidad de Valencia, Instituto Geológico y Minero de España, EspañaLaboratorio de Geotecnia, Centro de Estudios y Experimentación de Obras Públicas, EspañaDepartamento de Ingeniería Civil, Universidad Politécnica de Madrid, Españ

The Differential Slow Moving Dynamic of a Complex Landslide: Multi-sensor Monitoring

World Landslide Forum Ubicación (4th. 2017. Ljubljana, Slovenia

Site scale modeling of slow-moving landslides, a 3D viscoplastic finite element modeling approach

This paper presents an advanced 3D numerical methodology to reproduce the kinematics of slow active landslides, more precisely, to reproduce the nearly constant strain rate (secondary creep) and the acceleration/deceleration of the moving mass due to hydrological changes. For this purpose, finite element analyses are performed in a large area covering a long time-span (12 years), in order to exhibit different interacting slope movements. First, we perform a stability analysis using the shear strength reduction (SSR) technique with a Mohr-Coulomb failure criteria. It is done in order to compute factors of safety (FS) and to identify two different scenarios, the first one being stable (FS > 1) and the second one being unstable (FS < 1). In the studied test case, the Portalet landslide (Central Spanish Pyrenees), the first scenario corresponds to an initial stable configuration of the slope and the second one to an unstable excavated configuration. Second, taking the first scenario as an initial condition, a time-dependent analysis is performed using a coupled formulation to model solid skeleton and pore fluids interaction, and a simplified ground water model that takes into account daily rainfall intensity. In this case, a viscoplastic constitutive model based on Perzyna’s theory is applied to reproduce soil viscous behavior and the delayed creep deformation due to the excavation. The fluidity parameter is calibrated to reproduce displacements measured by the monitoring systems. Our results demonstrate that 3D analyses are preferable to 2D ones for reproducing in a more realistic way the slide behavior. After calibration, the proposed model is able to simulate successfully short- and medium-term predictions during stages of primary and secondary creep.Instituto de Geociencias, Consejo Superior de Investigaciones Científicas, EspañaInstituto de Geociencias, Universidad Complutense de Madrid, EspañaGeohazards InSAR Laboratory and Modeling Group, Instituto Geológico y Minero de España, Españ

The Eurogeosurveys strategy for landslide risk reduction

SRA-E-Iberian Chapter (SRA-E-I) Conference (2018. Toledo)The Geological Surveys of Europe present the results of an ongoing work started in 2014 to coordinate actions with the aim of reducing landslide risk in Europe. In order to do so, the following milestones have been reached: (1) a review of the existing landslide databases in the Geological Surveys of Europe; (2) the creation of a database on damaging landslides in Europe; (3) an evaluation of the level of integration of landslide assessment maps into land use and urban planning. The results reveal heterogeneous policies across national borders, and a lack of knowledge about the actual extent of the social and economic impacts of landslides in many of the countries. This overview stresses the need for a common legislative framework for landslide hazards to support those countries that do not take landslide hazards into consideration in land-use and urban planning, along with those countries with deficiencies in their existing legislations.EuroGeoSurveys, BélgicaInstituto Geológico y Minero de España, EspañaInstitute of Geology and Mineral Exploration, GreciaEarth Observation and Geohazards Expert Group, EuroGeoSurveys, Bélgic