Statistical analysis of different seismogenic zonings of the Iberian Peninsula and adjacent areas through a Geographic Information System

The knowledge of the seismic hazard in the Iberian Peninsula (IP) and its neighboring area is important to address the mitigation of damage that earthquakes could cause in it. The occurrence of earthquakes in the area is quite frequent because it is in the contact zone between the Eurasian Plate and the African Plate. The general objective of this document is the calculation, representation and analysis of a set of seismic parameters (b-value, maximum magnitude and annual rate of earthquakes per unit area) of the Iberian Peninsula and its adjacent area, considering geographic information systems (GIS) as a basic working tool. These systems allow the integration of data from different information sources, as well as rigorous and quality analysis and graphical representations. To achieve this goal, having a quality seismic catalog is essential. Therefore, one has been compiled for the area as complete, rigorous and extensive in the time possible, and further, revised, homogeneous in size (magnitude) and with independent events. This has served as the basis for the works exposed here. For the generation of this catalog, the database of earthquakes of the National Geographic Institute of Spain has been consider as a starting point, that has been revised (especially the magnitude) and completed with other databases and specific studies. In addition, the catalog of work has included earthquakes for which only macroseismic (and reliable) information is available as well as those recorded during the instrumental period according to the scientific advances of each moment. Then, the size of all the events has been transformed to moment magnitude (Mw) in order to compare it, taking into account only the events with Mw greater or equal to 3.0. Subsequently, a process of elimination of non-main shocks (foreshocks, aftershocks and swarms) has been carried out. Finally, a completeness date has been considered for each magnitude. In this thesis, the b-value, the annual rate of earthquakes per unit area and the maximum magnitude have been calculated, represented and analyzed. In addition, it has been done through two approaches. The first deals with zoning related to Spanish seismic regulations and are based on both geological characteristics and seismicity of the area; and others that are based on objective and mathematically robust criteria and considers only seismicity. In the second approach, a set of multiresolution grids have been established, in which zonings are defined according to a purely geographic criterion. The size of the cells (zones) has been 0.5º x 0.5º for the calculation of the maximum magnitude recorded and 1º x 1º and 2º x 2º for the b-value and the annual rate normalized with the area. In both types of zoning, after the calculations and the representation of the seismic parameters, an analysis of them has been carried out. From this analysis it can be deduced that in some areas there has not been a quantity of events that allows to derive seismic parameters with solidity from a statistical point of view. It can also be concluded that earthquakes with maximum recorded magnitude have a marine epicenter and are located in the SW of the IP. Moreover, the b-value takes a value of 1.0 or somewhat lower in the contact zone between the Eurasian and African plates (a value that decreases further to the east), while in the mainland, 1.2 can be considered an approximate value, with somewhat higher values in some areas. Finally, regarding the annual rate, it should be noted that the highest values (close to 1E-3 events / km2) appear in the Granada basin and in the Pyrenees Region and to a lesser extent, to the SW of Cabo de San Vicente, in Galicia and a large part of the southeast of the IP where values greater than 1E-4 are exceeded.El conocimiento de la peligrosidad sísmica en la península ibérica y su entorno es importante para abordar la mitigación de los daños que los terremotos podrían causar en la misma. La ocurrencia de terremotos en el área es bastante frecuente porque se encuentra en la zona de contacto entre la placa euroasiática y la africana. El objetivo general de esta tesis doctoral es el cálculo, representación y análisis de un conjunto de parámetros que intervienen en la definición de la peligrosidad sísmica de la península ibérica y su área adyacente, considerando como herramienta básica de trabajo los sistemas de información geográfica. Estos permiten la integración de datos de distintas fuentes de información, así como el análisis y representaciones gráficas rigurosas y de calidad. Para la consecución de este objetivo, el disponer de un catálogo sísmico de calidad es fundamental. Por tanto, se ha compilado uno para la zona lo más completo, riguroso y extenso en el tiempo posible y además, revisado, homogéneo en tamaño (magnitud) y con eventos independientes. Este ha servido como base para los trabajos que aquí se exponen. Para la generación del mismo, se ha partido de la base de datos de terremotos del Instituto Geográfico Nacional de España, que se ha visto revisada (sobre todo la magnitud) y completada con otras bases de datos y estudios específicos. Además, en el catálogo del trabajo se han incluido, desde terremotos de los que únicamente se dispone de información macrosísmica (y fiable) como los registrados durante la época instrumental según los avances científicos de cada momento. Luego, se ha transformado el tamaño de todos los eventos a magnitud momento (Mw) para poder compararlo, tomando solo los eventos con Mw mayor o igual a 3,0. Posteriormente, se ha llevado a cabo un proceso de eliminación de terremotos no principales (premonitores, réplicas y enjambres). Finalmente, se ha considerado una fecha de completitud para cada magnitud. En esta tesis se han calculado, representado y analizado el parámetro b-value, la tasa anual de terremotos por unidad de área y la magnitud máxima. Además, se ha hecho a través de dos aproximaciones. La primera versa sobre zonificaciones relacionadas con la normativa sismorresistente española y basadas tanto en las características geológicas como en la sismicidad de la zona; y por otras que parten de criterios objetivos y robustos matemáticamente y están basadas solo en la sismicidad. En la segunda aproximación, se han establecido un conjunto de mallas multirresolución, en las que las zonificaciones son definidas según un criterio puramente geográfico. El tamaño de las celdas (zonas) ha sido de 0,5º x 0,5º para el cálculo de la magnitud máxima registrada y de 1º x 1º y 2º x 2º para el del b-value y la tasa anual normalizada con el área. En ambos tipos de zonificaciones, tras los cálculos y la representación de los parámetros sísmicos, se ha llevado a cabo un análisis de los mismos. De este se deduce que en algunas zonas no ha ocurrido una cantidad de eventos que permita extraer parámetros sísmicos con solidez desde un punto de vista estadístico. También se puede concluir que los terremotos con magnitud máxima registrada tienen epicentro marino y se encuentran al suroeste de la península ibérica. Por otro lado, el b-value toma un valor de 1,0 o algo menor en la zona de contacto entre las placas euroasiática y africana (valor que disminuye más al este), mientras que en tierra firme como valor aproximado se puede considerar 1,2, con valores algo mayores en algunas zonas. Finalmente, respecto a la tasa anual de terremotos, cabe comentar que los valores más altos (cercanos a 1E-3 eventos / km2) aparecen en la cuenca de Granada y en la región de los Pirineos y, en menor medida al SO del Cabo de San Vicente, en Galicia y gran parte del sureste peninsular donde se superan valores mayores a 1E-4.Premio Extraordinario de Doctorado U

A Comparison of Cartographic and Toponymic Databases in a Multilingual Environment: A Methodology for Detecting Redundancies Using ETL and GIS Tools

Toponymy, a transversal discipline for geography, linguistics, and history, finds one of its main supports in cartography. Due to exhaustiveness on the territory, cadastral cartography and its toponymy have the ideal characteristics to develop systematic geographical analyses. Moreover, cadastre and geographical names are part of the geographic reference data according to Annex 1 of the INSPIRE directive. This work presents the design, implementation, and application of a methodology based on Geographic Information Systems and Extract, Transform, and Load (ETL) tools for detecting coincidences between the cadastral geoinformation and the official gazetteer corresponding to the province of Gipuzkoa, Spain. Methodologically, this study proposes a solution to the issues raised by bilingualism in the study area. This problem is approached a priori, in the previous data treatment, and a posteriori, applying semantic criteria. The results show a match between the datasets of close to 40%. In this way, the uniqueness and richness of the analyzed source and its outstanding contribution to the potential integration of the official toponymic corpus are evidenced

GIS-Based Mapping of Seismic Parameters for the Pyrenees

In the present paper, three of the main seismic parameters, maximum magnitude -Mmax, b-value, and annual rate -AR, have been studied for the Pyrenees range in southwest Europe by a Geographic Information System (GIS). The main aim of this work is to calculate, represent continuously, and analyze some of the most crucial seismic indicators for this belt. To this end, an updated and homogenized Poissonian earthquake catalog has been generated, where the National Geographic Institute of Spain earthquake catalog has been considered as a starting point. Herein, the details about the catalog compilation, the magnitude homogenization, the declustering of the catalog, and the analysis of the completeness, are exposed. When the catalog has been produced, a GIS tool has been used to drive the parameters’ calculations and representations properly. Different grids (0.5 × 0.5° and 1 × 1°) have been created to depict a continuous map of these parameters. The b-value and AR have been obtained that take into account different pairs of magnitude–year of completeness. Mmax has been discretely obtained (by cells). The analysis of the results shows that the Central Pyrenees (mainly from Arudy to Bagnères de Bigorre) present the most pronounced seismicity in the range

Nuevas tecnologías y métodos tradicionales en el levantamiento de patrimonio arquitectónico

El propósito de esta comunicación es demostrar, tomando como hilo argumental trabajos realizados como prácticas de alumnos, cómo empleando herramientas de bajo coste y aplicando adecuadamente las nuevas tecnologías, pueden efectuarse levantamientos de edificios patrimoniales gracias a una combinación de métodos tradicionales y nuevas tecnologías. Estos trabajos están encaminados a generar documentos gráficos (la mayoría de las veces tridimensionales) que sirvan como inventario del patrimonio, pero también como punto de partida para realizar intervenciones sobre el mismo. La documentación generada abarca desde dibujos de líneas hasta modelados 3D con texturas, consiguiéndose dichos resultados con escaso coste tanto económico como humano. Los elementos que conforman el patrimonio están sujetos a cambios con lo que resulta muy útil tenerlos documentados en una fecha determinada. Así, se puede establecer su evolución en el tiempo ya que los edificios están sometidos a un riesgo de deterioro, destrucción, o simplemente estudiarlos desde la observación.The aim of this paper is to demonstrate, basing our argument on several heritage documentation works elaborated as students work placements, how with low cost tools and applying new technologies properly, heritage building surveys can be done using a mixture of traditional and newer methods. These studies are designed to generate graphic documents (most of them in 3D) that can be useful as heritage inventory, but also as a starting point to carry out performances in it. Generated documentation may cover from line drawing to 3D textured models, achieving these results with a low economic and human cost. Elements which make up heritage, particularly architectonic elements, are always changing therefore it is very worthwhile to document on a specific date. Thus, evolution over time can be supervised because buildings are exposed to deterioration risks, destruction, or simply to study them from watching them

Wavelet analysis of a Sentinel-2 time series to detect land use changes in agriculture in the Vega Alta of the Guadalquivir River: Cantillana case study (Seville)

Historically, the Vega Alta of the Guadalquivir River (southern Spain) has been an anthropized space. Over time, the dominance of latifundia agriculture has evolved towards more intensive citrus-based agriculture. In this study, wavelet algorithms applied to Sentinel-2 time series were used to determine both the expansion of citrus plantations and the level of intensification of these plantations within the municipality of Cantillana. Sentinel-2 provides comprehensive global coverage from March 2017 to the present. Our study applied a 90% power wavelet transformation for the creation of a wavelet-smoothed time series for four years of Sentinel-2 NDVI data. Based on the data, it can be stated that within our research region covering 5000 hectares of agricultural land, over a span of four years (2017 to 2020), more than 980 hectares of native vegetation and pasture were transformed into citrus orchards, giving rise, at the end of 2020, to a total area of 3250 ha. Analyzing unique spatial patterns within a wavelet-smoothed time series data is very useful for land management, as it allows land use changes to be controlled. For this reason, it becomes feasible to assess the reliability of the wavelet method using both remote sensing and GIS tools

Aplicaciones de las infraestructuras de datos espaciales en ingeniería y arquitectura. Ejemplos

El volumen de datos y servicios disponibles referentes a cualquier ámbito de la sociedad es cada vez más elevado, hecho quizá más palpable aún al hablar de información geográfica, ya que su uso se está democratizando en los últimos años. Esta circunstancia hace que la mayoría de los datos y servicios que se pretendan producir ya habrán sido capturados o generados, por lo que es fundamental disponer de herramientas adecuadas para conocer la existencia de los mismos así como su calidad (a través de los metadatos) con el fin de no generarlos de nuevo con el consiguiente coste. Ahora bien, se ha tenido que establecer un lenguaje, unos protocolos, unas tecnologías, etc. comunes para poder compartir y hacer interoperable dicha información. Esto corresponde a una evolución de los sistemas de información geográfica tradicionales y da lugar a las infraestructuras de datos espaciales (IDE). Además, la Directiva Europa INSPIRE 2007/2/CE, la Ley 37/2007 y la Ley 14/2010 (LISIGE) entre otras tratan de la producción y el mantenimiento de los datos, además de otros aspectos. En esta comunicación se presentan los conceptos básicos de las IDE y se muestran algunos ejemplos de las IDE en los que, a partir de información almacenada y actualizada por el propio productor de la misma, se accede a información útil para la ingeniería y la arquitectura

Developing experimental learning in a graphical course using Thurstone's Law of comparative judgment

In this paper, one innovative educational experiment to help student obtain a better way to learn spatial vision in graphical course was carried out. After implementation of the improvements into a graphical engineering course, an evaluation study, through surveys, was conducted to investigate the effectiveness of this visual experiment. This empirical study provided one hundred and sixty four andalusian freshmen three types of visualization (2D static depictions, 3D computer depictions and an augmented reality environment that allows multiple participants to interact with 2D and 3D data) required to improve their skills related to spatial vision. According to results, most students showed positive attitudes toward this practice. In addition, students perceived positive impacts of this effort on their learning experience. The responses to surveys illustrated that students prefer 3D traditional learning, however they think augmented reality learning is no useful for better visual understanding of different objects. [ABSTRACT FROM AUTHOR

Repercusión del empleo de la proyección UTM en el cálculo de la superficie de fincas

La representación de la Tierra o de una parte de ella lleva asociada una serie de limitaciones. La forma y dimensiones de la misma hacen que, cuando se trata de representar de forma métrica un territorio de cierta extensión, haya que trabajar con sistemas y superficies de referencia (elipsoides, esferas, etc.), así como con sistemas de representación o cartográficos (proyecciones cartográficas como UTM, Lambert, etc.). El hecho de trabajar con programas informáticos cada vez más potentes no debe enmascarar el trasfondo de conocimientos necesarios para dar resultados lo más correctos posibles o, en cualquier caso, saber qué limitaciones tiene el resultado aportado. El empleo de sistemas de representación conlleva una deformación (anamorfosis) aun cuando las proyecciones utilizadas son generalmente conformes (las formas se mantienen, pero no así las distancias – anamorfosis lineal– ni las superficies), por lo que esto deriva en que el valor de las distancias y superficies se ve alterado, siendo este valor el proporcionado por los programas de cálculo. En este trabajo, se analiza la repercusión de la ubicación de una finca en el cálculo de la superficie de la misma, cuando se trabaja con la proyección UTM, frente al valor que podría considerarse “sin deformación” a través de una serie de ejemplos.Representation of the Earth or a part of the same implies some restrictions. Its shape and size mean that, when representing a territory of a certain size in a metric manner, reference systems and surfaces must be used (ellipsoids, spheres, etc.), as well as representation or cartographic systems (cartographic projections such as UTM, Lambert, etc.). The use of increasingly powerful computer programs must not mask the background of knowledge that is necessary in order to reach the most accurate results possible or, in any case, to understand the limitations of the results obtained. The use of representation systems involves deformation (distortion) even when the projections used generally conformal (the shapes are maintained, but distances (lineal distortion) and surfaces are not), which leads to alteration of the values of the distances and surfaces, with this value being provided by the calculation programs. This work analyzes the impact of the location of an estate when calculating the surface of the same with UTM projection, in comparison with the value that could be considered "deformation-free" through a series of examples

A Novel Method for Seismogenic Zoning Based on Triclustering: Application to the Iberian Peninsula

A previous definition of seismogenic zones is required to do a probabilistic seismic hazard analysis for areas of spread and low seismic activity. Traditional zoning methods are based on the available seismic catalog and the geological structures. It is admitted that thermal and resistant parameters of the crust provide better criteria for zoning. Nonetheless, the working out of the rheological profiles causes a great uncertainty. This has generated inconsistencies, as different zones have been proposed for the same area. A new method for seismogenic zoning by means of triclustering is proposed in this research. The main advantage is that it is solely based on seismic data. Almost no human decision is made, and therefore, the method is nearly non-biased. To assess its performance, the method has been applied to the Iberian Peninsula, which is characterized by the occurrence of small to moderate magnitude earthquakes. The catalog of the National Geographic Institute of Spain has been used. The output map is checked for validity with the geology. Moreover, a geographic information system has been used for two purposes. First, the obtained zones have been depicted within it. Second, the data have been used to calculate the seismic parameters (b-value, annual rate). Finally, the results have been compared to Kohonen’s self-organizing maps.Ministerio de Economía y Competitividad TIN2014-55894-C2-RJunta de Andalucía P12-TIC-1728Universidad Pablo de Olavide APPB81309