Damage assessment on building structures subjected to the recent near-fault earthquake in Lorca (Spain)

The city of Lorca (Spain) was hit on May 11th 2011 by two consecutive earthquakes with 4.6 and 5.2 Mw respectively, causing casualties and important damage in buildings. Lorca is located in the south-east region of Spain and settled on the trace of the Murcia-Totana-Lorca fault. Although the magnitudes of these ground motions were not severe, the damage observed was considerable over a great amount of buildings. More than 300 of them have been demolished and many others are being retrofitted. This paper reports a field study on the damage caused by these earthquakes. The observed damage is related with the structural typology. Further, prototypes of the damaged buildings are idealized with nonlinear numerical models and their seismic behavior and proneness to damage concentration is further investigated through dynamic response analyses.

On the economics of energy consumption in 4G networks: the case of Spain

Reducing energy consumption is one of the main challenges in most countries. For example, European Member States agreed to reduce greenhouse gas (GHG) emissions by 20% in 2020 compared to 1990 levels (EC 2008). Considering each sector separately, ICTs account nowadays for 2% of total carbon emissions. This percentage will increase as the demand of communication services and applications steps up. At the same time, the expected evolution of ICT-based developments - smart buildings, smart grids and smart transportation systems among others - could result in the creation of energy-saving opportunities leading to global emission reductions (Labouze et al. 2008), although the amount of these savings is under debate (Falch 2010). The main development required in telecommunication networks ?one of the three major blocks of energy consumption in ICTs together with data centers and consumer equipment (Sutherland 2009) ? is the evolution of existing infrastructures into ultra-broadband networks, the so-called Next Generation Networks (NGN). Fourth generation (4G) mobile communications are the technology of choice to complete -or supplement- the ubiquitous deployment of NGN. The risk and opportunities involved in NGN roll-out are currently in the forefront of the economic and policy debate. However, the issue of which is the role of energy consumption in 4G networks seems absent, despite the fact that the economic impact of energy consumption arises as a key element in the cost analysis of this type of networks. Precisely, the aim of this research is to provide deeper insight on the energy consumption involved in the usage of a 4G network, its relationship with network main design features, and the general economic impact this would have in the capital and operational expenditures related with network deployment and usage.

Vulnerability analysis of RC buildings with wide beams located in moderate seismicity regions

A significant number of short-to-mid height RC buildings with wide beams have been constructed in areas of moderate seismicity of Spain, mainly for housing and administrative use. The buildings have a framed structure with one-way slabs; the wide beams constitute the distinctive characteristic, their depth being equal to that of the rest of the slab, thus providing a flat lower surface, convenient for construction and the layout of facilities. Seismic behavior in the direction of the wide beams appears to be deficient because of: (i) low lateral strength, mainly because of the small effective depth of the beams, (ii) inherent low ductility of the wide beams, generated by high amount of reinforcement, (iii) the big strut compressive forces developed inside the column-beam connections due to the low height of the beams, and (iv) the fact that the wide beams are wider than the columns, meaning that the contribution of the outer zones to the resistance of the beam-column joints is unreliable because there is no torsion reinforcement. In the orthogonal direction, the behavior is worse since the only members of the slabs that contribute to the lateral resistance are the joists and the façade beams. Moreover, these buildings were designed with codes that did not include ductility requirements and required only a low lateral resistance; indeed, in many cases, seismic action was not considered at all. Consequently, the seismic capacity of these structures is not reliable. The objective of this research is to assess numerically this capability, whereas further research will aim to propose retrofit strategies. The research approach consists of: (i) selecting a number of 3-story and 6-story buildings that represent the vast majority of the existing ones and (ii) evaluating their vulnerability through three types of analyses, namely: code-type, push-over and nonlinear dynamic analysis. Given the low lateral resistance of the main frames, the cooperation of the masonry infill walls is accounted for; for each representative building, three wall densities are considered. The results of the analyses show that the buildings in question exhibit inadequate seismic behavior in most of the examined situations. In general, the relative performance is less deficient for Target Drift CP (Collapse Prevention) than for IO (Immediate Occupancy). Since these buildings are selected to be representative of the vast majority of buildings with wide beams that were constructed in Spain without accounting for any seismic consideration, our conclusions can be extrapolated to a broader scenario.

Effects of conservation interventions on the archaeological Roman site of Merida (Spain). Advance of research.

Research on the assessment of the effects of conservation/restoration treatments on stone material has been significant in recent years, with focus on the early observation of decay caused by the application of these treatments. However, in the case of archaeological sites, research is still scarce and few studies on the subject have been published. Restoration, as everything else, has changed according to trends, mainly guided by the release of new products and technologies, an experimental field where scientific assessment of suitability, efficacy and durability pre-evaluations of treatments are not always conducted. Some efforts have been made to solve this problem in the architectural field, where functional needs and technical requirements force to set clear standards. Unfortunately, archaeological sites, unlike historic buildings, have specific features that preclude the extrapolation of these results. A critical review of the methodologies, products and restoration materials is necessary, coupled with deeper research on degradation mechanisms caused by these treatments in the mid- and long-term. The aim of this paper is to introduce the research on the above issues using Merida as a case study.

Application of a building cost estimation model to the appraisal of the churches damaged by earthquakes in Lorca (Spain)

The objective of this paper is the development of a building cost estimation model whose purpose is to quickly and precisely evaluate rebuilding costs for historic heritage buildings affected by catastrophic events. Specifically, this study will be applied to the monumental buildings owned by the Catholic Church that were affected by two earthquakes on May 11, 2011 in the town of Lorca. To estimate the initial total replacement cost new, calculation model will be applied which, on the one hand, will use two-dimensional metric exterior parameters and, on the other, three-dimensional interior cubic parameters. Based on the total of the analyzed buildings, and considering damage caused by the seismic event, the final reconstruction cost for the building units ruined by the earthquakes can be estimated. The proposed calculation model can also be applied to other emergency scenarios and situations for the quick estimation of construction costs necessary for rebuilding historic heritage buildings which have been affected by catastrophic events that deteriorate or ruin their structural or constructive configuration.

First steps of Roman Cement in Spain

Natural cement was patented in 1796 but it didn’t arrive in Spain until 1835. No one knows exactly where the production started in Spain, because it emerged independently at the same time in many places. Most of these outbreaks are concentrated in the north and northwest of Spain: Basque Country (Zumaya and Rezola) and Catalonia (San Celoní and San Juan de las Abadesas).Natural cement was extensively used to decorate historical buildings during the nineteenth and beginning of twentieth century in Madrid. It was the building material which realised the architects and builders dreams of mass-produced cast elements in a wide variety of styles. Its arrival replaced traditional materials that were used previously (lime, gypsum and hydraulic limes). However, its use was not extended in time, and soon it was replaced by the use of artificial Portland cements. During 20th century this building material disappeared from use. What remains is it’s memory, in thousands and thousands of “stone witnesses” in our cities. Final properties of the cement largely depend on raw materials used and its combustion temperature. However, it was characterised by an easily implementation on facade masonry, fast-setting (about 15 minutes), good resistance , an agreeable structural consistency and colour.This article aims to show first steps, evolution and decay of Natural Cement Industry in Spain and its application in Madrid.

Alfredo Payá. Alicante, Spain

In his retreat in Alicante, where he gives calm and deliverate classes at the city's new architecture school , ALFREDO PAYA ls a serene and centered architect who transmits these qualities through the buildings he constructs .

Enhanced radon emission in natural CO2 flows in Campo de Calatrava region (central Spain)

Activity of radon gas in natural soils is commonly low (in the order of few thousands of Bq·m-3) due to the fast decay (half-life= 3.8 days in the case of 222Rn) that prevents accumulation in soil pores. Exceptionally, high Rn soil activity (up to 430 KBq·m-3) is found around point sources of deep CO2 fluxes. These fluxes allow the transport of trace gases (including Rn) to long distances in the geosphere leading to a potential hazard as Rn accumulation in buildings. CO2 degassing is common in active or ancient volcanic fields and occurs as free gas fluxes or dissolved in groundwater. In this work, the occurrence of Rnbearing, CO2 fluxes from the Campo de Calatrava region in Central Spain has been studied in order to determine their (1) magnitude, (2) migration paths and (3) potential impact on the environment, and (4) methodologies to best detection and measurement.

Domes of adobe and stone on the rural architecture of centre of Castilla y León (Spain)

In the centre of Castilla y León (extensive zone of Spain) still there are some examples of the old rural buildings linked to the economic activities that have been developed in the agrarian field. These are called chozos and casetas, and they have been erected with domed solutions using the autochthonous materi-als: the mud in the region of Tierra de Campos and the stone in the region of Montes Torozos. The influence of traditional construction techniques of both elements has generated a singular typological range rarely seen in the rest of the Península Ibérica. All different types of domes found in this place will be explained from its construction process, adding its structural capacity and energy bioclimatic qualities. -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- En el centro de Castilla y León todavía se mantienen algunos ejemplos de antiguas construcciones rurales vinculadas a las actividades económicas que se han desarrollado en el ámbito agrario. Éstas, conocidas como chozos y casetas, han sido ejecutadas con soluciones cupuliformes empleándose los materiales que más a mano se disponen, siendo el barro más característico en la región de Tierra de Campos y la piedra en la comarca de Montes Torozos. La influencia de las técnicas constructivas tradicionales de ambos elementos ha generado un abanico tipológico singular poco visto en el resto de la península. Los diferentes tipos de cúpulas encontrados se explicarán desde su proceso constructivo, añadiendo su capacidad estructural y sus cualidades bioclimáticas.

Assessment of expected damage on buildings subjected to Lorca earthquake through an energy-based seismic index method and nonlinear dynamic response analyses

The city of Lorca (Spain) was hit on May 11th, 2011, by two consecutive earth-quakes of magnitudes 4.6 and 5.2 Mw, causing casualties and important damage in buildings. Many of the damaged structures were reinforced concrete frames with wide beams. This study quantifies the expected level of damage on this structural type in the case of the Lorca earth-quake by means of a seismic index Iv that compares the energy input by the earthquake with the energy absorption/dissipation capacity of the structure. The prototype frames investigated represent structures designed in two time periods (1994–2002 and 2003–2008), in which the applicable codes were different. The influence of the masonry infill walls and the proneness of the frames to concentrate damage in a given story were further investigated through nonlinear dynamic response analyses. It is found that (1) the seismic index method predicts levels of damage that range from moderate/severe to complete collapse; this prediction is consistent with the observed damage; (2) the presence of masonry infill walls makes the structure very prone to damage concentration and reduces the overall seismic capacity of the building; and (3) a proper hierarchy of strength between beams and columns that guarantees the formation of a strong column-weak beam mechanism (as prescribed by seismic codes), as well as the adoption of counter-measures to avoid the negative interaction between non-structural infill walls and the main frame, would have reduced the level of damage from Iv=1 (collapse) to about Iv=0.5 (moderate/severe damage)

Juan Bautista Lázaro y la restauración monumental: su intervención en la Catedral de León (1892-1909)

La catedral de León, debido al estado de ruina que presentaba a mediados del siglo XIX, se vio sometida a partir de entonces a una serie de intervenciones de conservación, restauración y reconstrucción que la transforma-ron significativamente. A pesar de encontrarnos con gran cantidad de documentación escrita sobre este monumento y de existir varios estudios sobre los arquitectos restauradores que intervinieron en este a finales del siglo XIX, resulta sorprendente que todavía existan períodos de este lapso de tiempo en el que su análisis y profundización haya sido menor. Este es el caso del período de Juan Bautista Lázaro como arquitecto director de las obras de la catedral leonesa, existiendo únicamente sobre toda su obra un estudio general que fue realizado por el director de este trabajo de investigación, por lo que nos llevó a considerar que era oportuno profundizar sobre la figura y obra de uno de los arquitectos más importante de la restauración en España de este período, no solo por su obra en sí, sino también por sus pos-turas significativas respecto a la intervención en el patrimonio arquitectónico: su respeto por los añadidos históricos, su preferencia por no aislar los monumentos, sus interés por los sistemas constructivos y su deseo de recuperar los oficios tradicionales que estaban completamente perdidos en la España decimonónica. El objetivo principal de la tesis es, por tanto, el análisis descriptivo y arquitectónico de los proyectos e intervenciones que Lázaro desarrolló y ejecutó para la catedral de Santa María de Regla de León, para deducir los principios e ideas que guiaron su quehacer en este templo, y poder, tras estudiar sus diversas publicaciones escritas y los proyectos e intervenciones de restauración acometidas en otros edificios de carácter monumental, llegar a establecer sus criterios de intervención en el patrimonio histórico y artístico. De acuerdo con esto, la tesis se estructura en tres partes: una primera parte en la que se contempla el pensamiento arquitectónico de Lázaro en su intervención en el patrimonio histórico; una segunda, en la que se abordan directamente los proyectos e intervenciones de Lázaro en la pulchra leonina, previa aproximación del citado arquitecto al proceso de restauración que se acometía en dicho templo; y una tercera, en la que se realiza el estudio de las principales intervenciones de restauración que ejecutó en otros edificios del patrimonio arquitectónico español. El presente trabajo de investigación se ha servido de la documentación escrita, gráfica, planimétrica y fotográfica que sobre los temas tratados existe desperdigada en diversos archivos dependientes de distintos organismos oficiales civiles y eclesiásticos. Además, el hecho de haber podido acceder a los trabajos de conservación y restauración que en estos momentos se están llevando a cabo en las zonas en las que intervino Lázaro (vidrieras, rejas, puertas, fábricas, cubiertas, etc.), y el poder intercambiar opiniones y criterios con la persona que actualmente es responsable de las obras de la catedral de León, ha facilitado y complementado el desarrollo de la presente tesis al haber podido contrastar y tomar datos directamente en el monumento objeto de estudio. También se ha llevado a cabo la consulta de las distintas revistas de arquitectura publicadas en aquellos años y de los múltiples libros que versaban sobre los edificios objeto de este trabajo o que guardaban relación con ellos. Asimismo hemos logrado conocer el testimonio de algunos de los herederos de Lázaro y de varios de los descendientes de los operarios que trabajaron bajo sus órdenes. Como conclusiones generales, la tesis define por primera vez los criterios generales que guiaron su quehacer profesional en el patrimonio. Además, en este trabajo se analizan pormenorizadamente los proyectos y actuaciones de Lázaro en la catedral de León, abordándose también en profundidad el trabajo del mencionado arquitecto en el ámbito de la restauración arquitectónica. Para lograr este objetivo, esta tesis no se ha limitado únicamente a analizar la información existente en los proyectos y en los in-formes de supervisión de los mismos, como tradicionalmente se había hecho, sino que también se ha tratado de verificar si los datos contenidos en los diferentes documentos de un mismo proyecto y en los borradores de los mismos tenían relación y coherencia entre sí. Además, se ha procurado realizar el análisis comparativo de la realidad construida con el contenido de los proyectos, liquidaciones y documentos de la fase de ejecución de las obras. Este análisis comparativo no había sido realizado hasta la fecha, siendo este, por tanto, una de las aportaciones del trabajo. Por último, la tesis abre tres vías de investigación futuras (que ya se han tratado y avanzado en parte, pero que escapan a los límites de este trabajo). Estas se refieren al estudio de la evolución de la representación gráfica de los planos de la catedral leonesa catalogados en este trabajo, de la actividad pública de Lázaro y su preocupación por la defensa del patrimonio como diputado en las Cortes, arquitecto municipal de Ávila y arquitecto diocesano de Ávila y Toledo, y de cómo sus actuaciones de restauración en el patrimonio arquitectónico influyeron en los proyectos de obra nueva que construyó. ABSTRACT Due to the state of ruin in mid-nineteenth century, the Cathedral of Santa Maria de Regla of León was subjected to a series of interventions on conservation, restoration and reconstruction that transformed it significantly. There have been several studies on the architects who took part in the restoration during the mentioned century and despite abundant documentation and research on this monument, it is surprising to note the lack of deep analysis in some of the periods. In particular, the interventions accomplished by Juan Bautista Lázaro, as chief architect of the works of the Cathedral of León, have not been documented and analysed in adequate depth, despite the outstanding recognition of his work nationally and internationally. Furthermore, up to date, only the director of this research had conducted a general research of all his architectural work. For these reasons, we felt it was appropriate to elaborate on the life and work of one of the most important architects of the restoration in Spain during that period, not only for his work itself, but also for his significant contribution to the debate on architectural interventions on heritage. He is notable for his respect to historical additions, his preference for not isolating the monuments, his interest in building systems and his continuous desire to re-cover the traditional crafts that were completely lost in the nineteenth century in Spain. The main aim of this thesis is therefore the descriptive and architectural analysis of Lázaro’s projects and interventions developed and executed for the Cathedral of León. The thesis identifies the principles and ideas that guided his work in this temple and establish the criteria for intervention in the historical and artistic heritage architecture he applied after studying its various print publications, projects and restoration works undertaken in other buildings. Accordingly, the thesis is structured in three parts: the first part where it deals Lázaro’s architectural thinking in his interventions on heritage constructions; the second one, in which analyses the projects and interventions carried out by Lazaro in the “pulchra leonina”, but this analysis is preceded by the description of Lázaro’s relationship with the Cathedral of León before taking charge of its restoration in 1892; and the third and final section, in which the study of major restoration interventions implemented by Lázaro in other buildings of Spanish architectural heritage is made. This research has used available documentation (in written or graphic form, plans or photographs) scattered in a diverse range of archives de-pendent on various civil and ecclesiastical institutions. Moreover, we could access the conservation and restoration works, currently being carried out in areas where Lázaro intervened (stained glass windows, forged iron en-closures, gates, doors, masonry, covers, etc.). It has been possible to ex-change views and opinions with the person currently in charge of the referred restoration works which has facilitated and complemented the development of this thesis. It further, it has allowed contrasting and obtaining data directly from the monument under study. Consultation of various architectural journals published in those years has also been taken into account, as well as a diversity of books and articles which concerned the buildings assessed in this work, or related to them. Also, although not with the results expected, it has been obtained the testimony of some of Lázaro’s descendants as well as descendants of the workers who operated under him. As a general conclusion, the thesis defines the general criteria that guided his professional work in the heritage for the first time. Furthermore, Juan Bautista Lázaro’s projects and interventions in the Cathedral of León are analysed in detail. Also, it has been studying in detail the Lazaro’s work in the architectural heritage. To achieve this goal, the thesis has studied not only the information from the official projects and technical reports of them, but also it has been tried to verify if the information contained in the different documents of the same project and in the drafts were related and consistent with each other. In addition, it has been attempted to per-form a comparative analysis of the execution of Lázaro’s projects and the entire projected content. This comparative study had not been done to date and this will be, therefore, one of the main contributions of this re-search. Finally, this thesis opens up three lines of investigation (that have already been discussed and partially advanced, but which fall beyond the scope of this research). These refer to the study of the evolution of the graphical representation of the plans of Leon Cathedral catalogued in this thesis, public activity of Lazaro and his concern for the defence of heritage as deputy in Parliament, municipal architect of Avila, and as diocesan architect Ávila and Toledo, and even more how its restoration actions in architectural heritage influenced his projects of new construction.

Las teorías del gótico y su representación gráfica en España el último tercio del siglo XIX. Un estudio sobre: Some Account of Gothic Architecture in Spain, de George Edmund Street

La tesis se centra en el estudio, descripción y análisis del libro publicado por el arquitecto británico George Edmund Street en 1865, bajo el título Some Account of Gothic Architecture in Spain. El libro dio a conocer una de la colecciones más importantes de dibujos realizada en el siglo XIX sobre la arquitectura gótica española, y por lo tanto fue una primera referencia para su estudio, hasta bien entrado el siglo veinte. El volumen incluyó 107 grabados de diversos tipos de edificios con perspectivas y detalles, y 25 láminas con 45 planos de plantas de iglesias y claustros, muchos de ellos publicados por primera vez. Gracias a varias campañas de verano por la mitad norte del país, la casi inexplorada -desde un punto de vista académico- arquitectura española medieval fue finalmente descubierta. Este hecho conduce a una pregunta intrigante que está en el origen de esta investigación ¿cómo pudo Street en pocos viajes sentar las bases de la historia del gótico español que hasta entonces los estudiosos españoles no habían sido capaces de definir? Esta tesis comienza describiendo la obra de Street en su contexto cultural con un breve repaso a su biografía y a su posición profesional y teórica. También su relación con las personas más representativas que participaron en el estudio de la arquitectura gótica, como Robert Willis, William Whewell, Augustus Pugin, o George G. Scott. Se ha prestado especial atención, en explicar su papel relevante en el Gothic Revival, para entender el significado de su interés en la arquitectura gótica continental. Estos capítulos preliminares son seguidos por una revisión del papel del dibujo como herramienta para la arquitectura de los viajeros en sus rutas en busca de la arquitectura gótica. También se trata la influencia de la Royal Academy y sus académicos, (entre los cuales estuvo Street) y su formación académica. Finalmente la tesis entra en el estudio de los planos arquitectónicos que Street hizo durante sus viajes continentales de arquitectura, seguido por una descripción detallada de sus dibujos de España, analizando su método, su técnica, y las nuevas características aportadas, que fueron una novedad en el contexto español. También se lleva a cabo algunos estudios comparativos de los dibujos de España, gracias a una recopilación exhaustiva de bocetos y dibujos originales de Street, que en su gran mayoría se conservan en los archivos del RIBA, cotejándolos con sus versiones finales, con dibujos de la época de otros autores sobre los mismos edificios, y con fotos recientes. La tesis deja claro por qué y cómo Street, gracias a su soporte teórico y habilidades para el dibujo, pudo realizar algo que había pasado desapercibido para los estudiosos españoles de la época (construcción, historia de los estilos, señalamiento de períodos constructivos), lo que le permitió encontrar el lugar adecuado de la arquitectura gótica española en la historia y en el mapa de la arquitectura gótica europea. ABSTRACT This thesis focuses on the study, description and analysis of the book published by the British architect George Edmund Street in 1865, under the title Some Account of Gothic Architecture in Spain. The book displayed one of the most significant collections of drawings on Spanish Gothic Architecture made in the nineteenth century, and therefore was a first reference for its study, until well into the twentieth century. The book included 107 engravings, the surveying of various types of buildings with perspectives and details, and 25 sheets containing 45 ground plans of churches and cloisters, many of them new and published for the first time. Thanks to several summer campaigns in the north half of the country, the almost unexplored -from a scholar point of view- medieval Spanish architecture was eventually revealed. This fact lead to an intriguing question that is at the origin of this research: how could Street in a few trips lay the foundations of the history of Spanish Gothic that until then Spanish scholars had not been able to define? This thesis begins inscribing this Street's work in his cultural context. A brief review of his biography and professional and theoretical positions has been seen as necessary. Also his debts and relationship with the most representative people involved in the study of Gothic architecture, like Robert Willis, William Whewell, Augustus Pugin, or George G. Scott are discussed. Special attention has been paid, taken into account his relevant role in the Gothic Revival, to understand the significance of his interest in continental Gothic architecture. These preliminary chapters are followed by a review of role of drawing as a tool for Architectural travellers in their Tours in search of the Gothic architecture. The influence of the Royal Academy and its academicians, (among which was Street) and his educational background are here tackled. Eventually this thesis enters into the study of the architectural drawings Street made during his continental architectural journeys, which is followed by a detailed description and analysis of the Spanish ones: his methods, his technique, and the new features which were a novelty in the Spanish context are explored. Also in this thesis is carried out some comparative studies thanks to a previous exhaustive gathering of Street's sketches and original drawings, most of which are preserved in the RIBA archives. Their final versions, drawings of the same buildings from other contemporary draughtsman and pictures of their current state are compared with them. This thesis makes clear why and how Street thanks to his theoretical back-ground and portraying skills could realize what have passed unnoticed by contemporary Spanish scholars (construction, genealogy of forms, dating of periods) allowing him to find the proper place of the Spanish architecture in the history and the map of European Gothic architecture.

An integrated assessment of two decades of air pollution policy making in Spain: Impacts, costs and improvements

This paper analyses the effects of policy making for air pollution abatement in Spain between 2000 and 2020 under an integrated assessment approach with the AERIS model for number of pollutants (NOx/NO2, PM10/PM2.5, O3, SO2, NH3 and VOC). The analysis of the effects of air pollution focused on different aspects: compliance with the European limit values of Directive 2008/50/EC for NO2 and PM10 for the Spanish air quality management areas; the evaluation of impacts caused by the deposition of atmospheric sulphur and nitrogen on ecosystems; the exceedance of critical levels of NO2 and SO2 in forest areas; the analysis of O3-induced crop damage for grapes, maize, potato, rice, tobacco, tomato, watermelon and wheat; health impacts caused by human exposure to O3 and PM2.5; and costs on society due to crop losses (O3), disability-related absence of work staff and damage to buildings and public property due to soot-related soiling (PM2.5). In general, air quality policy making has delivered improvements in air quality levels throughout Spain and has mitigated the severity of the impacts on ecosystems, health and vegetation in 2020 as target year. The findings of this work constitute an appropriate diagnosis for identifying improvement potentials for further mitigation for policy makers and stakeholders in Spain.

Relationship between piezometric level and ground deformations measured by means of DInSAR in the Vega Media of the Segura River (Spain)

Differential SAR Interferometry (DInSAR) is a remote sensing method with the well demonstrated ability to monitor geological hazards like earthquakes, landslides and subsidence. Among all these hazards, subsidence involves the settlement of the ground surface affecting wide areas. Frequently, subsidence is induced by overexploitation of aquifers and constitutes a common problem that affects developed societies. The excessive pumping of underground water decreases the piezometric level in the subsoil and, as a consequence, increases the effective stresses with depth causing a consolidation of the soil column. This consolidation originates a settlement of ground surface that must be withstood by civil structures built on these areas. In this paper we make use of an advanced DInSAR approach - the Coherent Pixels Technique (CPT) [1] - to monitor subsidence induced by aquifer overexploitation in the Vega Media of the Segura River (SE Spain) from 1993 to the present. 28 ERS-1/2 scenes covering a time interval of about 10 years were used to study this phenomenon. The deformation map retrieved with CPT technique shows settlements of up to 80 mm at some points of the studied zone. These values agree with data obtained by means of borehole extensometers, but not with the distribution of damaged buildings, well points and basements, because the occurrence of damages also depends on the structural quality of the buildings and their foundations. The most interesting relationship observed is the one existing between piezometric changes, settlement evolution and local geology. Three main patterns of ground surface and piezometric level behaviour have been distinguished for the study zone during this period: 1) areas where deformation occurs while ground conditions remain altered (recent deformable sediments), 2) areas with no deformation (old and non-deformable materials), and 3) areas where ground deformation mimics piezometric level changes (expansive soils). The temporal relationship between deformation patterns and soil characteristics has been analysed in this work, showing a delay between them. Moreover, this technique has allowed the measurement of ground subsidence for a period (1993-1995) where no instrument information was available.

Forensic analysis of buildings affected by mining subsidence based on Differential Interferometry (Part III)

This work presents a forensic analysis of buildings affected by mining subsidence, which is based on deformation data obtained by Differential Interferometry (DInSAR). The proposed test site is La Union village (Murcia, SE Spain) where subsidence was triggered in an industrial area due to the collapse of abandoned underground mining labours occurred in 1998. In the first part of this work the study area was introduced, describing the spatial and temporal evolution of ground subsidence, through the elaboration of a cracks map on the buildings located within the affected area. In the second part, the evolution of the most significant cracks found in the most damaged buildings was monitored using biaxial extensometric units and inclinometers. This article describes the work performed in the third part, where DInSAR processing of satellite radar data, available between 1998 and 2008, has permitted to determine the spatial and temporal evolution of the deformation of all the buildings of the study area in a period when no continuous in situ instrumental data is available. Additionally, the comparison of these results with the forensic data gathered in the 2005–2008 period, reveal that there is a coincidence between damaged buildings, buildings where extensometers register significant movements of cracks, and buildings deformation estimated from radar data. As a result, it has been demonstrated that the integration of DInSAR data into forensic analysis methodologies contributes to improve significantly the assessment of the damages of buildings affected by mining subsidence.