Satellite SAR interferometry for monitoring dam deformation in Portugal

The paper offers three examples of satellite SAR interferometry (InSAR) application for monitoring dam deformations: Paradela, Raiva and Alto Ceira, all of them in Portugal. Dam deformations were estimated using several sets of ERS and Envisat C-band SAR data by PS-InSAR method that offers accuracy of a millimeter per year at monitoring man-made tructures. The results show potential of InSAR but also summarize limits of C-band InSAR in these particular cases and can be handful to recognize applicability of new Sentinel-1 data (since 2014) for continuous monitoring of dam deformations. While Alto Ceira dam lies in SAR radar shadow and was represented by only one observable point, and the movement detected (in satellite line-of-sight direction) appears to fit with geodetical measurements. Raiva and Paradela dams were represented by sufficient number of points feasible for PS-InSAR processing. Deformations at slope near to Raiva dam and slow linear movements of the center of Paradela dam were detected

Monitorización de infraestructuras críticas expuestas a riesgos naturales y antrópicos mediante interferometría radar de satélite

[EN] Synthetic Aperture Radar Interferometry (InSAR) is a remote sensing technique very effective for the measure of smalldisplacements of the Earth’s surface over large areas at a very low cost as compared with conventional geodetictechniques. Advanced InSAR time series algorithms for monitoring and investigating surface displacement on Earth arebased on conventional radar interferometry. These techniques allow us to measure deformation with uncertainties of 1mm/year, interpreting time series of interferometric phases at coherent point scatterers (PS) without the need for humanor special equipment presence on the site. By applying InSAR processing techniques to a series of radar images over thesame region, it is possible to detect line-of-sight (LOS) displacements of infrastructures on the ground and therefore identifyabnormal or excessive movement indicating potential problems requiring detailed ground investigation. A major advantageof this technology is that a single radar image can cover a major area of up to 100 km by 100 km or more as, for example,Sentinel-1 C-band satellites data cover a 250 km wide swath. Therefore, all engineering infrastructures in the area, suchas dams, dikes, bridges, ports, etc. subject to terrain deformation by volcanos, landslides, subsidence due to groundwater,gas, or oil withdrawal could be monitored, reducing operating costs effectively. In this sense, the free and open accessCopernicus Sentinel-1 data with currently up to 6-days revisit time open new opportunities for a near real-time landmonitoring. In addition, the new generation of high-resolution radar imagery acquired by SAR sensors such as TerraSARX,COSMO-SkyMed, and PAZ, and the development of multi-interferogram techniques has enhanced our capabilities inrecent years in using InSAR as deformation monitoring tool. In this paper, we address the applicability of using spaceborneSAR sensors for monitoring infrastructures in geomatics engineering and present several cases studies carried out by ourgroup related to anthropogenic and natural hazards, as well as monitoring of critical infrastructures.[ES] La interferometría radar de apertura sintética (InSAR) es una técnica de teledetección muy eficaz para medir pequeños desplazamientos de la superficie terrestre en grandes áreas a un coste muy pequeño en comparación con las técnicas geodésicas convencionales. Los algoritmos avanzados de series temporales InSAR para monitorizar e investigar el desplazamiento de la superficie terrestre se basan en la interferometría radar convencional. Estas técnicas nos permiten medir la deformación con incertidumbres de un milímetro por año, interpretando series temporales de fases interferométricas en retrodispersores puntuales coherentes (PS) sin necesidad de presencia humana o de equipos especiales en el sitio. Al aplicar técnicas de procesamiento InSAR a una serie de imágenes radar de la misma región, es posible detectar desplazamientos de infraestructuras proyectados en la línea de vista del satélite (line-of-sight o LOS) y, por lo tanto, identificar movimientos anormales o excesivos que indiquen problemas potenciales que requieran una investigación detallada del terreno. Una de las principales ventajas de esta tecnología es que una sola imagen radar puede cubrir un área importante de hasta 100 km por 100 km o más, ya que, por ejemplo, los datos de los satélites de banda C Sentinel-1 cubren una franja de 250 km de ancho. Por lo tanto, todas las infraestructuras civiles de la zona, como presas, diques, puentes, puertos, etc., sujetas a deformaciones del terreno por actividad volcánica, deslizamientos de tierra, hundimientos por extracción de agua subterránea, gas o petróleo, podrían ser monitorizados, reduciendo los costes operativos de manera efectiva. En este sentido, los datos Sentinel-1 de Copernicus, de acceso abierto, con hasta 6 días de tiempo de revisión actual abren nuevas oportunidades para una monitorización terrestre casi en tiempo real. Además, la nueva generación de imágenes radar de alta resolución adquiridas por sensores SAR como TerraSAR-X, COSMOSkyMed y PAZ, y el desarrollo de técnicas multi-interferograma ha mejorado nuestras capacidades en los últimos años en el uso del InSAR como herramienta para el control de deformaciones. En este trabajo se aborda la aplicabilidad del uso de sensores SAR espaciales para la monitorización de infraestructuras civiles en ingeniería geomática y presentamos varios casos de estudio realizados por nuestro grupo relacionados con riesgos naturales y antrópicos, así como de monitorización de infraestructura crítica.ERS-1/2 and Envisat datasets were provided by the European Space Agency (ESA). Sentinel-1A/B data were freely provided by ESA through Copernicus Programme. Data have been processed by DORIS (TUDelft), StaMPS (Andy Hooper), SARPROZ (Copyright (c) 2009-2020 Daniele Perissin), and SNAP (ESA). The satellite orbits are from TUDelft and ESA, as well as from the ESA Quality Control Group of Sentinel-1. Research was supported by [ESA Research and Service Support] for providing hardware resources employed in this work; [Spanish Ministry of Economy, Industry and Competitiveness] under ReMoDams project ESP2017-89344-R (AEI/FEDER, UE); [University of Jaén (Spain)] under PAIUJA-2021/2022 and CEACTEMA; [Junta de Andalucía (Spain)] under RNM-282 research group; [ERDF through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme] within project «POCI-01-0145-FEDER006961»; [National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology)] as part of project UID/EEA/50014/2013; [The Ministry of Education, Youth and Sports from the National Programme of Sustainability (NPU II)] under project «IT4Innovations excellence in science - LQ1602» (Czech Republic); and [Slovak Grant Agency VEGA] under projects No. 2/0100/20Ruiz-Armenteros, A.; Delgado-Blasco, J.; Bakon, M.; Lazecky, M.; Marchamalo-Sacristán, M.; Lamas-Fernández, F.; Ruiz-Constán, A.... (2021). Monitoring critical infrastructure exposed to anthropogenic and natural hazards using satellite radar interferometry. En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 137-146. https://doi.org/10.4995/CiGeo2021.2021.12736OCS13714

Analiza wybranych wskaźników ekonomiczno-środowiskowych systemu gospodarki odpadami na Słowacji

The main objective of the paper was to visualize and analyze the relationships between selected economic and environmental indicators in the waste management system of Slovakia, i.e., the amount of fees for municipal waste in individual districts of Slovakia in 2019 and the amount of average monthly wage and unemployment in Slovakia in the same year. Data were visualized and analyzed on a thematic map and in a boxplot, and subsequently, they were subjected to statistical testing. Based on the performed analysis, we can confirm the statistical relationship between the average wage and the amount of fees for municipal waste collection and the statistical relation between the municipal waste fee and the unemployment rate in individual districts of Slovakia.Głównym celem artykułu była wizualizacja oraz analiza zależności pomiędzy wybranymi wskaźnikami ekonomiczno-środowiskowymi systemu gospodarki odpadami na Słowacji, tj. pomiędzy wysokością opłaty za odpady komunalne w poszczególnych rejonach Słowacji a wysokością średniego miesięcznego wynagrodzenia oraz poziomem bezrobocia w 2019 roku. Dane zostały zwizualizowane przy użyciu mapy tematycznej oraz wykresu typu boxplot, następnie zostały poddane testom statystycznym. Na podstawie przeprowadzonej analizy potwierdzono statystyczną zależność pomiędzy średnim wynagrodzeniem a wysokością opłaty za wywóz odpadów komunalnych oraz statystyczną zależność pomiędzy opłatą za odpady komunalne a stopą bezrobocia w poszczególnych rejonach Słowacji

Heat Equation as a Tool for Outliers Mitigation in Run-Off Triangles for Valuing the Technical Provisions in Non-Life Insurance Business

Estimating outstanding claims reserves in the non-life insurance business is often impaired by outlier-contaminated datasets. Widely used methods to eliminate outliers in non-life development triangles are either limiting the number of outliers by robust statistical methods or by change of development factors. However, the whole estimation process is likewise adversely affected so that: (i) the total sum of all triangle payments is not correct or (ii) the difference between the original triangle and its backward estimation via the bootstrap method is ineligible. In this paper, the properties of the heat equation are examined to obtain an outlier smoothing technique for development triangles. The heat equation in two dimensions is being applied on an outlier contaminated dataset where no individual data are available. As a result, we introduce a new methodology to (i) treat outliers in non-life development triangles, (ii) keep the total sum of all triangle payments, and (iii) provide acceptable differences between the original and the backward estimated triangle. Consequently, the outlying values are eliminated and the resulting development triangle could be used as an input for any claims reserving method without a need for further robustification or change of development factors. Additionally, the research on the application of heat equation in one dimension presented in this paper enables one to employ the bootstrap method using Pearson’s residuals in cases where the method was originally inapplicable due to development factors being lower than one

Infrastructure Non-linear Deformation Monitoring Via Satellite Radar Interferometry

AbstractThe advantages of satellite radar interferometry for displacement monitoring are demonstrated in the cases of monitoring man-made structures, i.e., buildings, bridges and dams. Presented are the results from application of PSInSAR technology using ENVISAT radar images over urban area of Bratislava (Slovakia). As a whole, the investigated urban area of Bratislava is stable with the linear displacement trends of ±3mm/year. However, a non-linear approach reveals small movements on the structures without prior interest of any regarding conventional monitoring technique. Thanks to the development of high resolution SAR sensors (e.g. TerraSAR-X) many permanent scatterers can be found in one individual man-made construction. Moreover, with the shorter revisit times, it is possible to process a long series of SAR data and expand standard PS model to account for a seasonal expansion due to changes in water level and/or temperature. The topic of separation between deformations and seasonal movements is discussed within the exploitation of TerraSAR-X data for deformation monitoring of Plover Cove Dam and building of Hyatt Hotel, both located in Hong Kong. Data have been processed using advanced processing techniques implemented in SARPROZ. These techniques show high potential for continuous monitoring of ground motion and structure stability in civil surveillance

Środowiskowe aspekty zachowań zakupowych konsumentów w sklepach bez opakowań

One of the recent biggest environmental problems is pollution by excessive waste produc-tion. One of the ways to partially eliminate this problem is packaging-free stores. The paper focuses on analysing the environmental behaviour of individual generations of consumers concerning shopping in packaging-free stores. A questionnaire survey served as a source for data gathering. In the analysis, we applied the method of descriptive statistics and mathematical-statistical methods (Shapiro-Wilk W test, Kruskal Wallis test, Wilcoxon rank-sum test) to verify the difference between generational groups of consumers and their awareness of packaging-free stores. Another verified variables were the gender of respondents and their experience of shopping in a packaging-free store. The research results confirmed that packaging-free stores should focus their marketing activities on all generations of consumers and focus on finding appropriate ways to increase the level of interest of all age groups.Jednym z problemów środowiskowych jest obciążenie spowodowane nadmierną produkcją odpadów. Sposobem na częściowe wyeliminowanie tego problemu są sklepy bez opakowań. W artykule skupiono się na analizie zachowań proekologicznych poszczególnych generacji konsumentów dokonujących zakupów w sklepach bez opakowań. Źródłem pozyskania danych były badania ankietowe. W analizie zastosowano metodę statystyki opisowej oraz metody matematyczno-statystyczne (test Shapiro-Wilka, test Kruskala Wallisa, test Wilcoxona) w celu weryfikacji różnic między grupami pokoleniowymi konsumentów oraz ich świadomości na temat sklepów bez opakowań. Kolejnymi weryfikowanymi zmiennymi były płeć respondentów oraz ich doświadczenie z zakupami w sklepie bez opakowań. Wyniki badań potwierdziły, że sklepy bez opakowań powinny skoncentrować swoje działania marketingowe na konsumentach wszystkich pokoleń i skupić się na znalezieniu odpowiednich sposobów na zwiększenie poziomu zainteresowania wszystkich grup wiekowych

Ujęcie analityczne postrzegania wybranych problemów środowiskowych we wschodniej Słowacji: perspektywa pokoleniowa

The aim of the paper was to evaluate and compare respondents' views from eastern Slovakia on selected environmental issues from a generational perspective. The study used an online question-naire survey to collect the data. According to the results, each generation views the severity of environ-mental problems differently, with Generation Y placing the highest priority on them and the Baby Boomers placing the lowest. Based on the performed statistical testing, we can confirm a statistically significant difference between individual generations of respondents on the question of the Covid-19 pandemic's positive impact on the environment, but no statistically significant difference between individual generations of respondents on whether they think waste sorting and recycling reduces the amount of waste deposited in landfills or whether they think waste sorting and recycling increases the amount of waste deposited in landfills.Celem artykułu była ocena i porównanie poglądów respondentów ze wschodniej Słowacji na wybrane zagadnienia środowiskowe z perspektywy pokoleniowej. W badaniu wykorzystano ankietę internetową do zebrania danych. Zgodnie z wynikami, każde pokolenie inaczej postrzega powagę problemów środowiskowych, przy czym pokolenie Y stawia im najwyższy priorytet, a Baby Boomers najniższy. Na podstawie przeprowadzonych badań statystycznych możemy potwierdzić statystycznie istotną różnicę między poszczególnymi pokoleniami respondentów w kwestii pozytywnego wpływu pandemii Covid-19 na środowisko, ale brak statystycznie istotnej różnicy między poszczególnymi pokoleniami respondentów w kwestii oceny tego, czy sortowanie odpadów i recykling zmniejsza ilość odpadów deponowanych na składowiskach czy też zwiększa ilość odpadów deponowanych na składowiskach

Ground Stability Monitoring of Undermined and Landslide Prone Areas by Means of Sentinel-1 Multi-Temporal InSAR, Case Study from Slovakia

Multi-temporal synthetic aperture radar interferometry techniques (MT-InSAR) are nowadays a well-developed remote sensing tool for ground stability monitoring of areas afflicted by natural hazards. Its application capability has recently been emphasized by the Sentinel-1 satellite mission, providing extensive spatial coverage, regular temporal sampling and free data availability. We perform MT-InSAR analysis over the wider Upper Nitra region in Slovakia, utilizing all Sentinel-1 images acquired since November 2014 until March 2017. This region is notable for its extensive landslide susceptibility as well as intensive brown coal mining. We focus on two case studies, being impaired by recent activation of these geohazards, which caused serious damage to local structures. We incorporate a processing chain based on open-source tools, combining the current Sentinel Application Platform (SNAP) and Stanford Method for Persistent Scatterers (StaMPS) implementation. MT-InSAR results reveal substantial activity at both case studies, exceeding the annual displacement velocities of 30 mm/year. Moreover, our observations are validated and their accuracy is confirmed via comparison with ground truth data from borehole inclinometers and terrestrial levelling. Detected displacement time series provide valuable insight into the spatio-temporal evolution of corresponding deformation phenomena and are thus complementary to conventional terrestrial monitoring techniques. At the same time, they not only demonstrate the feasibility of MT-InSAR for the assessment of remediation works, but also constitute the possibility of operational monitoring and routine landslide inventory updates, regarding the free Sentinel-1 data

Monitoring instabilities by MT-InSAR in a mesa placed town (Arjona, Guadalquivir valley, South Spain)

[EN] Cities in Spain use to be overgrown around old towns (preroman, roman and medieval) constructed on topographic defensive heights of singular geological features. In the upper Guadalquivir valley, a tabular body of Miocene sediments has been eroded forming mesas where most of its population has been living since middle age. As the towns grew, new neighborhoods settled towards the edges and cliffs of these mesas, in areas with high probabilities of instability. The town of Arjona is a good example of this geological-urbanistic setup, located on the tabular hill formed by clay marls topped by bioclastic limestones that protect it from erosion. Modern buildings from few sectors of the town show important cracks, even the 16th century bell-tower has a 4º inclination indicating problems in the foundations. Multi-temporal SAR interferometry (MT-InSAR) is a powerful technique to derive displacement time series over coherent targets on the Earth associated with geophysical or structural instabilities phenomena. In this work we use MT-InSAR with Sentinel-1 data to reveal that, at present day, the periphery of Arjona is active, being recognized a large landslide in the south side of this mesa town which affects buildings and civil infrastructures. In addition, field work is being carried out to investigate the sources of these instabilities.Ruiz-Armenteros, A.; Sánchez-Gómez, M.; Delgado-Blasco, JM.; Bakon, M.; Ruiz-Constán, A.; Galindo-Zaldívar, J.; Lazecky, M.... (2023). Monitoring instabilities by MT-InSAR in a mesa placed town (Arjona, Guadalquivir valley, South Spain). Editorial Universitat Politècnica de València. 413-419. https://doi.org/10.4995/JISDM2022.2022.1388541341