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(English) Coastal areas support important ecosystems with great ecological value, giving rise to countless resources increasingly exploited by humans. Understanding the processes occurring in both inland and aquatic ecosystems, as well as their mutual interactions, and with anthropic activities is required. In this line, the new generation of high-resolution multispectral Sentinel satellites (Sentinel-2; S2) extend the capabilities for the integrated monitoring of coastal areas thanks to their spatial and temporal resolutions (up to 10 m and 5 days). However, global remote sensing issues/limitations (e.g., cloud screening, spectral mixing, atmospheric correction) and regional-specific characteristics (e.g., involved ecosystems, economic fabric, interlinkages), make up challenges of diverse nature. The basis of the research presented in this thesis is to explore the potential of S2 for the monitoring of coastal areas, and the associated technical and scientific questions. The work is focused on the processing of S2 imagery for characterizing Ebro Delta (Spain) coastal features and their dynamics, involving aquaculture, agriculture, spatial planning, environmental monitoring, and preparedness for natural hazards. From atmospheric correction and image pre-processing (first steps) to data modelling and analysis (last steps), a number of technical and scientific challenges have been addressed. In coastal waters, different atmospheric correction levels, processors, spectral combinations, and statistical models have been used for mapping water quality (i.e., chlorophyll-a, Secchi disk depth) and macrophytes (i.e., seagrass, macroalgae). For estimating chlorophyll-a (proxy of phytoplankton biomass), the best results were obtained using simple ratios including visible and/or red-edge bands applied to Rayleigh or full-atmospheric corrected imagery, by fitting either linear or 2nd-degree polynomial (MAE ~ 0.6 mg/m3), obtaining time series which allowed to relate the distributi, (Català) Les zones costaneres alberguen importants ecosistemes de gran valor ecològic, que donen lloc a innumerables recursos cada cop més explotats per l’ésser humà. Per això, és necessari comprendre els processos que ocorren tant en els ecosistemes terrestres com en els aquàtics, així com les seves interaccions mútues i amb les activitats antròpiques. En aquesta línia, la nova generació de satèl·lits multiespectrals Sentinel d’alta resolució (Sentinel-2; S2) amplia les capacitats per a la monitorització integrada de les zones costaneres gràcies a les seves resolucions temporals i espacials millorades (fins 10 m i 5 dies). Tanmateix, els problemes/limitacions globals de la teledetecció (e.g., triatge de núvols, barreja espectral, correcció atmosfèrica) i les característiques específiques de cada regió (e.g., ecosistemes implicats, teixit econòmic del lloc, interrelacions), composen reptes de diversa naturalesa. En aquest sentit, la base de la investigació presentada en aquesta tesi és explorar el potencial de S2 per a la monitorització de zones costaneres, i les qüestions tècniques i científiques associades. El treball es centra en el processat d’imatges S2 per a la caracterització d’aspectes costaners al Delta de l’Ebre (Espanya) i la seva dinàmica, involucrant l’aqüicultura, l’agricultura, la planificació espacial, el seguiment mediambiental, i la preparació front a riscos naturals. Des de la correcció atmosfèrica i el pre-processat de les imatges (primers passos) fins el modelat i l’anàlisi de les dades (últims passos), s’han abordat diferents reptes tècnics i científics. En aigües costaneres, s’han utilitzat diferents nivells de correcció atmosfèrica, processadors, combinacions espectrals i models estadístics per a cartografiar la qualitat de l’aigua (i.e., clorofil·la-a, profunditat del disc de Secchi) i els macròfits (i.e., praderes marines, macroalgues). Per estimar la clorofil·la-a (indicador de biomassa fitoplanctònica), els millors resultats es van obteni, (Español) Las zonas costeras albergan importantes ecosistemas de gran valor ecológico, que dan lugar a innumerables recursos cada vez más explotados por el ser humano. Por ello, es necesario comprender los procesos que ocurren tanto en los ecosistemas terrestres como en los acuáticos, así como sus interacciones mutuas y con las actividades antrópicas. En esta línea, la nueva generación de satélites multiespectrales Sentinel de alta resolución (Sentinel-2; S2) amplía las capacidades para la monitorización integrada de las zonas costeras gracias a su resolución espacial y temporal (hasta 10 m y 5 días). Sin embargo, los problemas/limitaciones globales de la teledetección (e.g., cribado de nubes, mezcla espectral, corrección atmosférica) y las características específicas de cada región (e.g., ecosistemas implicados, tejido económico del lugar, interrelaciones), componen retos de diversa naturaleza. En este sentido, la base de la investigación presentada en esta tesis es explorar el potencial de S2 para la monitorización de zonas costaras, y las cuestiones técnicas y científicas asociadas. El trabajo se centra en el procesamiento de imágenes S2 para la caracterización de aspectos costeros del Delta del Ebro (España) y su dinámica, involucrando la acuicultura, la agricultura, la planificación espacial, el seguimiento medioambiental, y la preparación ante riesgos naturales. Desde la corrección atmosférica y el preprocesamiento de las imágenes (primeros pasos) hasta el modelado y el análisis de los datos (últimos pasos), se han abordado distintos retos técnicos y científicos. En las aguas costeras, se han utilizado diferentes niveles de corrección atmosférica, procesadores, combinaciones espectrales y modelos estadísticos para cartografiar la calidad del agua (i.e., clorofila-a, profundidad del disco de Secchi) y los macrófitos (i.e., praderas marinas, macroalgas). Para estimar la clorofila-a (indicador de la biomasa fitoplanctónica), los mejores resultados se obtuvieron u, Postprint (published version)

(English) In post-seismic scenarios, the rapid and safe evaluation of structural damage is essential to develop an effective response during the recovery, rehabilitation and reconstruction stages. The development of new inspection tools based on the use of remote sensors that make access to the interior of damaged buildings unnecessary, thus safeguarding the lives of technicians, is promising. This thesis work investigates the feasibility of using natural vibrations to detect the structural health status of buildings, in order to distinguish structurally unsafe or unstable states from safe configurations. The theoretical basis underlying the research is that the modal properties of buildings change with damage accumulation. Three axes structure the proposal to develop new safe and rapidly applicable inspection tools: i) Advanced numerical modelling of buildings in three dimensions (3D); ii) The application of advanced methodologies for assessing the vulnerability, fragility and seismic damage of structures: iii) The use of original and novel technology based on microwave interferometry and using a real aperture radar (RAR), for the remote measurement of vibrations in structures excited by ambient noise. The object of study has been medium-rise housing constructions belonging to one of the most common construction typologies in Spain, such as reinforced concrete buildings with waffle or unidirectional slabs and with an inner wall system built with hollow ceramic brick masonry. As case studies, two buildings affected by the earthquake (Mw 5.1), which occurred in Lorca on May 11, 2011, and an operational building located in Barcelona have been selected. The methodology used to estimate the vulnerability and damage states observed in these buildings are those considered as standards in advanced seismic risk analysis programs. The necessary calculations to evaluate the modal behaviour, as well as the structural performance against specific seismic demands, are the capaci, (Español) En escenarios post-sísmicos, la evaluación rápida y segura del daño estructural es esencial para desarrollar una respuesta eficaz durante las etapas de recuperación, rehabilitación y reconstrucción. Es prometedor el desarrollo de nuevas herramientas de inspección basadas en el uso de sensores remotos que hacen innecesario el acceso al interior de los edificios dañados, salvaguardando de este modo, la vida de los técnicos. Este trabajo de tesis investiga la viabilidad de utilizar vibraciones naturales para detectar el estado de salud estructural de los edificios, con el objeto de distinguir estados estructuralmente inseguros o inestables de configuraciones seguras. La base teórica que sustenta la investigación es que las propiedades modales de los edificios cambian con la acumulación de daño. Tres ejes estructuran la propuesta para desarrollar nuevas herramientas de inspección seguras y de rápida aplicación: i) La modelización numérica avanzada de los edificios en tres dimensiones (3D); ii) La aplicación de metodologías avanzadas de evaluación de la vulnerabilidad, la fragilidad y el daño sísmico de las estructuras; iii) La utilización de tecnología original y novedosa basada en la interferometría de microondas y empleando un radar de apertura real (RAR), para la medición remota de vibraciones en estructuras excitadas por ruido ambiente. El objeto de estudio han sido construcciones habitacionales de altura media pertenecientes a una de las tipologías constructivas más comunes en España como son los edificios de hormigón armado con forjados reticulares o unidireccionales y con un sistema de cerramientos construidos con fábrica de ladrillo cerámico hueco. Como casos de estudio, se han seleccionado dos edificios afectados por el sismo (Mw 5,1), ocurrido en Lorca el 11 de mayo de 2011, y un edificio sano y en servicio situado en Barcelona. La metodología utilizada para estimar la vulnerabilidad y los estados de daño observados en estos edificios, son los consid, Postprint (published version)

Shoreline represents the boundary between land and sea, and its accurate extraction is of utmost importance because of the economic and ecological value of coastal areas. Nowadays, satellite remote sensing is widely used for monitoring the natural environment. Indeed, satellite remote sensing data are cost-effective and periodically available over large areas at a relatively high spatial resolution. Hence, the automatic shoreline extraction from satellite images is a fundamental task for coastal monitoring and management. Shoreline extraction methods are usually applied to satellite remote sensing data. The goal of this study is to compare the performance of different shoreline extraction methods, such as thresholding and more complex classification approaches, such as Random Forest (RF), Minimum Distance (MD), Maximum Likelihood (ML) and K-means, using both optical and radar images. The considered case study area is the shallow basin of the Orbetello Lagoon and one of its ayre called Feniglia. The data supplier is the Copernicus program, which, through the Sentinel-1 and Sentinel-2 missions, provides medium-resolution, open-access products. The accuracy of the obtained results from both methodologies is checked by validating the extracted shoreline using an aerial orthomosaic and, subsequently, a manually extracted shoreline. A preliminary accuracy assessment was performed for image classification, focusing on extracting four classes: water, soil, urban, and forest, using manual segmentation as a reference. In terms of deviation from the reference shoreline, the results obtained through the analysed methodologies achieved an accuracy of 3.75 m, less than half of the pixel size of the Sentinel-1 and Sentinel-2 used products., Peer Reviewed, Postprint (published version)

A five-story reinforced concrete building severely damaged during the Mw 5.1, May 11th 2011, Lorca earthquake (Murcia, Spain), has been monitored with an interferometric radar and has been numerically modelled with the aim to study the evolution of the structural damage. An initial non-damaged and a final damaged configuration of the building after the earthquake have been modelled first. Radar measurements helped to calibrate the models. Four intermediate models, with damage configurations representing four steps of cumulative damage of the building facing the earthquake, have been built based on the information related to the building seismic damage included in a technical report. The objectives were to obtain calibrated numerical models, to perform a modal analysis, to calculate the capacity curve, and to study the evolution of the natural periods and the strength capacity of the building within each damage configuration representing the incremental damage process. Results show that a growth of 20% in the values of natural periods and reductions of 50% in the capacity lead the building over the severe damage state threshold. The interferometric radar is a suitable remote sensing technique to identify, in a rapid screening, the natural periods of mid and tall damaged buildings., This research has been partially funded by the Spanish Research Agency (AEI) of the Spanish Ministry of Science and Innovation (MICIN) through project with reference: PID2020-117374RB-I00/AEI/10.13039/501100011033, and by the European Regional Development Fund (ERDF) of the European Union (EU) through project with reference EFA158/16/POCRISC (INTERREG/POCTEFA. EU). Esteban Cabrera, sponsored by the University of Azuay (UDA), obtained a scholarship from the Ministry of Higher Education, Science and Technology, SENESCYT, Government of Ecuador, for doctoral studies in the Earthquake Engineering program at UPC-Barcelona-Tech. Yeudy F. Vargas-Alzate has been granted an Individual Fellowship (IF) in the research grants program of the Marie Sklodowska-Curie Actions (MSCA) of the European Union/European (H2020-MSCA-IF-2017) No 799553., Postprint (published version)

[EN] The objective of the POCTEFA - MOMPA project (Monitoring of Ground Movements and Action Protocol) is to provide a useful technical-operational tool for the prevention and management of risks due to slope movements, at a cross-border level, based on the satellite monitoring technique InSAR (Synthetic Aperture Radar Inteferometry). The tool includes two main elements: the risk evaluation, and the integration of the technique in an action protocol for the administrations in charge of Civil Protection. The study area covers around 4,000 km2 and includes a part of the eastern Pyrenees, including the countries of Spain, France, and Andorra. The project deals with risk assessment based on the ground displacement map at an interregional scale and on the detected Active Deformation Areas (ADA), to select movements with potential risk where it will then focus on an analysis at a local scale using traditional methods (photo interpretation and field work). Both the free medium-resolution data, acquired by the Sentinel-1 satellite, as well as the high-resolution data acquired by COSMO-SkyMed are used. In addition, the project focuses on the landslide event of “la Portalada” (in Andorra) that occurred in 2019. Today the slope shows a slow movement that could affect a main road located at the bottom of the valley. The Government of Andorra is implementing measures to monitor and characterize the current movement of the slope. Therefore, nine artificial reflectors were installed along this forested slope. The data obtained will be integrated into the risk prevention protocol. Here, the project and the first results obtained through satellite interferometry are presented., [ES] El objetivo del proyecto POCTEFA - MOMPA (MOnitorización de Movimientos del terreno y Protocolo de Actuación) es proporcionar una herramienta técnico-operativa útil para la prevención y la gestión de los riesgos ocasionados por movimientos de ladera, a nivel transfronterizo, basada en la técnica de seguimiento satelital InSAR. (Interferometría Radar a Apertura Sintética) La herramienta incluye dos elementos principales: la evaluación del riesgo; y la integración de la técnica en un protocolo de actuación para las administraciones encargadas de la Protección Civil. El área de estudio cubre alrededor de 4.000 km2 e incluye una parte de los Pirineos orientales, incluyendo los países España, Francia y Andorra. El proyecto trata la evaluación de riesgos a partir del mapa de movimientos del terreno a escala interregional y de las Áreas de Deformación Activa (ADA), para seleccionar movimientos con riesgo potencial donde luego se enfocará en un análisis a escala local mediante el uso de métodos tradicionales (básicamente fotointerpretación y trabajo de campo). Se utilizan tanto los datos libres y gratuitos de resolución media, adquiridos por el satélite Sentinel-1, como los datos de alta resolución adquiridos por COSMO-SkyMed. Además, el proyecto centra su atención en el caso particular del deslizamiento de “la Portalada” (Andorra) ocurrido en 2019. En la actualidad, la ladera presenta un movimiento lento que podría afectar el eje principal de comunicación entre Andorra y España ubicado en el fondo del valle. El Gobierno de Andorra está implementando medidas para monitorear y caracterizar el movimiento actual de la ladera. Por tanto, nueve reflectores artificiales se instalaron a lo largo de esta ladera ocupada por un bosque. Los datos obtenidos se integrarán en el protocolo de prevención de riesgos. En este trabajo se presentan el proyecto y los primeros resultados obtenidos mediante interferometría satelital.

This paper is focused on the design, implementation and testing of an active reflector, to be used to support deformation monitoring studies based on Synthetic Aperture Radar interferometry. The device is designed to work in C-band with Sentinel-1 data, operating at 5.405 GHz ± 50 MHz. A brief description of the active reflector is provided. It consists of two antennas and an amplifying section. The active reflector has been tested in different experiments. In this paper, we describe the experiment carried out in the Parc Mediterrani de la Tecnologia (Castelldefels, Barcelona). The result shows a strong correlation with temperature. A calibration test was carried out to experimentally derive a calibration curve to correct the effect of temperature on phase stability., This work is part of a project that has received funding from the European GNSS Agency under the European Union’s Horizon 2020 research and innovation programme, with grant agreement No 776335, project GIMS, “Geodetic Integrated Monitoring System”. This work has been partially funded by AGAUR, Generalitat de Catalunya, through the Consolidated Research Group RSE, “Remote Sensing” (Ref: 2017-SGR-00729), Postprint (published version)

In this paper, remote and in situ techniques to estimate the dynamic response of a building to ambient vibration are reported: data acquired through a real-aperture radar (RAR) interferometer and conventional accelerometers are analyzed. A five-story reinforced concrete housing building, which was damaged during the May 11th 2011 Lorca (Spain) earthquake, is used as a case study. The building was monitored using both types of instruments. The dynamic properties of the building are estimated first taking acceleration measurements using a set of 10 high-precision accelerometers installed on the roof of the building. Further, the displacement–time histories, recorded with the RAR device pointing to a corner of the building, are analyzed. Then, the ability and shortcomings of RAR measurements to deal with the fundamental frequencies of vibration of the structure are investigated. The advantages and limitations of from-inside (accelerometric) and from-outside (RAR) measurements are highlighted and discussed. A relevant conclusion is that, after strong earthquakes, RAR may be an interesting and useful tool, as it allows surveying the structural response of mid-rise buildings remotely, without the need to enter the structures, which may be dangerous for inspectors or technicians in cases of severely damaged buildings. Given that the instrumented building suffered significant damage, the ability of these kinds of measurements to detect damage is also discussed., This research has been partially funded by the Ministry of Economy and Competitiveness (MINECO) of the Spanish Government and by the European Regional Development Fund (ERDF) of the European Union (EU) through projects with references CGL2015-65913-P (MINECO/ERDF, EU) and EFA158/16/POCRISC (INTERREG/POCTEFA. EU). R.E.A. holds a PhD fellowship from the Consejo Nacional de Ciencia y Tecnología (CONACyT) in México. L.A.P. is supported by a Ph.D. scholarship grant from the Institute for the Training and Development of Human Resources (IFARHU) and the Government of Panama’s National Secretariat of Science, Technology, and Innovation (SENACYT)., Peer Reviewed, Postprint (published version)