Assessment of Urban Subsidence in the Lisbon Metropolitan Area (Central-West of Portugal) Applying Sentinel-1 SAR Dataset and Active Deformation Areas Procedure

The Lisbon metropolitan area (LMA, central-west of Portugal) has been severely affected by different geohazards (flooding episodes, landslides, subsidence, and earthquakes) that have generated considerable damage to properties and infrastructures, in the order of millions of euros per year. This study is focused on the analysis of subsidence, as related to urban and industrial activity. Utilizing the A-DInSAR dataset and applying active deformation areas (ADA) processing at the regional scale has allowed us to perform a detailed analysis of subsidence phenomena in the LMA. The dataset consisted of 48 ascending and 61 descending SAR IW-SLC images acquired by the Sentinel-1 A satellite between January 2018 and April 2020. The line-of-sight (LOS), mean deformation velocity (VLOS) maps (mm year(-1)), and deformation time series (mm) were obtained via the Geohazard Exploitation Platform service of the European Space Agency. The maximum VLOS detected, with ascending and descending datasets, were -38.0 and -32.2 mm year(-1), respectively. ADA processing over the LMA allowed for 592 ascending and 560 descending ADAs to be extracted and delimited. From the VLOS measured in both trajectories, a vertical velocity with a maximum value of -32.4 mm year(-1) was estimated. The analyzed subsidence was associated to four ascending and three descending ADAs and characterized by maximum VLOS of -25.5 and -25.2 mm year(-1). The maximum vertical velocity associated with urban subsidence was -32.4 mm year(-1). This subsidence is mainly linked to the compaction of the alluvial and anthropic deposits in the areas where urban and industrial sectors are located. The results of this work have allowed to: (1) detect and assess, from a quantitative point of view, the subsidence phenomena in populated and industrial areas of LMA; (2) establish the relationships between the subsidence phenomena and geological and hydrological characteristics.Programa de Apoyo y Promocion a la Investigacion 2021 at University of Oviedo PAPI-21-PF-22Project SLIDE-APCR FUO-21-069European Regional Development Fund (ERDF) through the project RISKCOAST of the Interreg SUDOE Programme SOE3/P4/E086

Landslide displacement forecasting using deep learning and monitoring data across selected sites

Accurate early warning systems for landslides are a reliable risk-reduction strategy that may significantly reduce fatalities and economic losses. Several machine learning methods have been examined for this purpose, underlying deep learning (DL) models’ remarkable prediction capabilities. The long short-term memory (LSTM) and gated recurrent unit (GRU) algorithms are the sole DL model studied in the extant comparisons. However, several other DL algorithms are suitable for time series forecasting tasks. In this paper, we assess, compare, and describe seven DL methods for forecasting future landslide displacement: multi-layer perception (MLP), LSTM, GRU, 1D convolutional neural network (1D CNN), 2xLSTM, bidirectional LSTM (bi-LSTM), and an architecture composed of 1D CNN and LSTM (Conv-LSTM). The investigation focuses on four landslides with different geographic locations, geological settings, time step dimensions, and measurement instruments. Two landslides are located in an artificial reservoir context, while the displacement of the other two is influenced just by rainfall. The results reveal that the MLP, GRU, and LSTM models can make reliable predictions in all four scenarios, while the Conv- LSTM model outperforms the others in the Baishuihe landslide, where the landslide is highly seasonal. No evident performance differences were found for landslides inside artificial reservoirs rather than outside. Furthermore, the research shows that MLP is better adapted to forecast the highest displacement peaks, while LSTM and GRU are better suited to model lower displacement peaks. We believe the findings of this research will serve as a precious aid when implementing a DL-based landslide early warning system (LEWS).SUPPORTO SCIENTIFICO PER L’OTTIMIZZAZIONE, IMPLEMENTAZIONE E GESTIONE DEL SISTEMA DI MONITORAGGIO CON AGGIORNAMENTO DELLE SOGLIE DI ALLERTAMENTO DEL FENOMENO FRANOSO DI SANT’ANDREA – PERAROLO DI CADORE (BL)” and the Spanish Grant “SARAI, PID2020-116540RB-C21,MCIN/AEI/10.13039/501100011033” and “RISKCOASTInSAR displacement data of the El Arrecife landslideGeohazard Exploitation Platform (GEP) of the European Space AgencyNoR Projects Sponsorship (Project ID: 63737

A gender- based approach to the current situation of Spanish dentists

To determine the perception of Spanish dentists about the situation of the profession nowadays and how the changes occurred in dental workforce (in number and gender of the past twenty years) have affected their personal and professional lives, under a g

Effect of Two Immediate Dentin Sealing Approaches on Bond Strength of Lava™ CAD/CAM Indirect Restoration

The study was conducted according to the guidelines of the Declaration of Helsinki, and approved by the Ethics Committee of the University of Granada (Spain) (protocol code #1005/CEIH/2019 approved on 13 January 2020).Informed consent was obtained from all subjects involved in the studyThe objective of this work was to compare the micro-tensile bond strength (mu TBS) of CAD/CAM (Computer-Aided Design/ Computer-Aided Manufacturing) specimens cemented with different pairing of adhesives and resin-cements using two Immediate Dentin Dealing (IDS) approaches in comparison with Delay Dentin Sealing (DDS). Coronal dentin from 108 molars were divided into nine groups (n = 12) depending on the adhesive/resin-cement (A-C) assigned. Lava (TM) Ultimate (4 x 10 x 10 mm) was cemented according to different strategies: IDS1(cementation after dentin sealing), DDS (dentin sealing and cementation at 2-weeks), IDS2 (immediate dentin sealing and cementation at 2-weeks). Samples were sectioned and tested until failure to determine the mu TBS. Failure mode was categorized as dentin/cement (DC), at Lava (TM) Ultimate/cement (LC) and hybrid (H). Kruskal-Wallis and Mann-Whitney U tests and influence of the type of failure on the mu TBS by survival analysis with competing risk was explored. Mostly, mu TBS values were equal or higher in IDS2 than DDS. In general, A-Cs that showed higher mu TBS, have high percentages of LC failure. Survival analysis with competing risk between DC + H and LC values showed that some A-Cs would significantly increase the mu TBS values for IDS2. A-Cs with the highest adhesion values showed a high percentage of fractures at the LC interface, suggesting that the adhesion at the adhesive/dentin interface would be higher

ADAtools: Automatic Detection and Classification of Active Deformation Areas from PSI Displacement Maps

This work describes the set of tools developed, tested, and put into production in the context of the H2020 project Multi-scale Observation and Monitoring of Railway Infrastructure Threats (MOMIT). This project, which ended in 2019, aimed to show how the use of various remote sensing techniques could help to improve the monitoring of railway infrastructures, such as tracks or bridges, and thus, consequently, improve the detection of ground instabilities and facilitate their management. Several lines of work were opened by MOMIT, but the authors of this work concentrated their efforts in the design of tools to help the detection and identification of ground movements using synthetic aperture radar interferometry (InSAR) data. The main output of this activity was a set of tools able to detect the areas labelled active deformation areas (ADA), with the highest deformation rates and to connect them to a geological or anthropogenic process. ADAtools is the name given to the aforementioned set of tools. The description of these tools includes the definition of their targets, inputs, and outputs, as well as details on how the correctness of the applications was checked and on the benchmarks showing their performance. The ADAtools include the following applications: ADAfinder, los2hv, ADAclassifier, and THEXfinder. The toolset is targeted at the analysis and interpretation of InSAR results. Ancillary information supports the semi-automatic interpretation and classification process. Two real use-cases illustrating this statement are included at the end of this paper to show the kind of results that may be obtained with the ADAtools.This work has received funding from the Shift2Rail Joint Undertaking under the European Union's Horizon 2020 research and innovation programme, with grant agreement No 777630, project MOMIT, “Multi-scale Observation and Monitoring of railway Infrastructure Threats”. It has been also partially funded by Interreg-Sudoe program of the EU, through the project RISKCOAST (Ref: SOE3/P4/E0868)

Improving landslide inventories by combining satellite interferometry and landscape analysis: the case of Sierra Nevada (Southern Spain)

An updated and complete landslide inventory is the starting point for an appropriate hazard assessment. This paper presents an improvement for landslide mapping by integrating data from two well-consolidated techniques: Differential Synthetic Aperture Radar (DInSAR) and Landscape Analysis through the normalised channel steepness index (ksn). The southwestern sector of the Sierra Nevada mountain range (Southern Spain) was selected as the case study. We first propose the double normalised steepness (ksnn) index, derived from the ksn index, to remove the active tectonics signal. The obtained ksnn anomalies (or knickzones) along rivers and the unstable ground areas from the DInSAR analysis rapidly highlighted the slopes of interest. Thus, we provided a new inventory of 28 landslides that implies an increase in the area affected by landslides compared with the previous mapping: 33.5% in the present study vs. 14.5% in the Spanish Land Movements Database. The two main typologies of identified landslides are Deep-Seated Gravitational Slope Deformations (DGSDs) and rockslides, with the prevalence of large DGSDs in Sierra Nevada being first revealed in this work. We also demonstrate that the combination of DInSAR and Landscape Analysis could overcome the limitations of each method for landslide detection. They also supported us in dealing with difficulties in recognising this type of landslides due to their poorly defined boundaries, a homogeneous lithology and the imprint of glacial and periglacial processes. Finally, a preliminary hazard perspective of these landslides was outlined.Universidad de Granada/CBUAMarie Curie Actions B-RNM-305-UGR18 A-RNM-508-UGR20 P18-RT-3632ERDF through the project RISKCOAST' of the Interreg SUDOE Programme SOE3/P4/E0868Project MORPHOMED' from the Spanish Ministry of Science (MCIN)/State Research Agency (SRA) PID2019-107138RB-I00Ramon y Cajal' Programme of the Spanish Ministry of Science RYC-2017-23335NoR 6373

Sentinel-1 DInSAR for Monitoring Active Landslides in Critical Infrastructures: The Case of the Rules Reservoir (Southern Spain)

We thank the editors and four anonymous reviewers for helpful comments and suggestions that improved the manuscript.Landslides in reservoir contexts are a well-recognised hazard that may lead to dangerous situations regarding infrastructures and people’s safety. Satellite-based radar interferometry is proving to be a reliable method to monitor the activity of landslides in such contexts. Here, we present a DInSAR (Differential Interferometric Synthetic Aperture Radar) analysis of Sentinel-1 images that exemplifies the usefulness of the technique to recognize and monitor landslides in the Rules Reservoir (Southern Spain). The integration of DInSAR results with a comprehensive geomorphological study allowed us to understand the typology, evolution and triggering factors of three active landslides: Lorenzo-1, Rules Viaduct and El Arrecife. We could distinguish between rotational and translational landslides and, thus, we evaluated the potential hazards related to these typologies, i.e., retrogression (Lorenzo-1 and Rules Viaduct landslides) or catastrophic slope failure (El Arrecife Landslide), respectively. We also observed how changes in the water level of the reservoir influence the landslide’s behaviour. Additionally, we were able to monitor the stability of the Rules Dam as well as detect the deformation of a highway viaduct that crosses a branch of the reservoir. Overall, we consider that other techniques must be applied to continue monitoring the movements, especially in the El Arrecife Landslide, in order to avoid future structural damages and fatalities.A Spanish “Sistema de Garantía Juvenil” research contract, founded by the Junta de Andalucía and the European Social Funds, supported the work of Cristina Reyes-Carmona. Spanish “Ramón y Cajal” grant supported part of the work of Jorge Pedro Galve. This work has been partially funded by the Spanish Ministry of Economy and Competitiveness through the DEMOS project “Deformation monitoring using Sentinel-1 data” (Ref: CGL2017-83704-P) and the LITHOSURF project “Respuesta de la topografía y la red de drenaje a procesos litosféricos y climáticos en el sur de Iberia” (Ref: CGL2015-67130-C2-1-R). This work has been partially developed in the framework of the RISKCOAST project (Ref: SOE3/P4/E0868) funded by the Interreg SUDOE program (3rd call for proposals)

ADATools: a set of tools for the analysis of terrain movement maps obtained with SAR Interferometry

The SAR Interferometry techniques, Persistent Scatterer Interferometry (PSI) among them, are nowadays known as important tools for monitoring Earth surface movements. Several regional and national Ground Motion Services based on PSI already exist. Moreover, since 2022 the European Ground Motion Service will be operational and will annually provide an updated displacement map over the whole Europe. This will suppose a big amount of ground displacement measurements along the European territory. For each measurement EGMS will provide the annual velocity and the time series of deformation covering the period 2014 to one year prior to each delivery. In this context, it will be more and more necessary having tools to ease the management, analysis, and interpretation, of those wide areas and huge amount of data. We present here a first step in this direction: the ADATools are a set of tools to automatically have secondary, and more operational, products derived from a PSI map. Starting from a fast extraction of the most significant Active Deformation Areas (ADA), with the ADAFinder tool, then we can have a preliminary classification of the most probable phenomena (landslides, subsidence, settlements, or sinkholes) that is behind the detected movement, with the ADAClassifier tool. Moreover, LOS2hv tool allows to derive the horizontal (east-west) and vertical components of the movement in case we have maps of ascending and descending geometries. Finally, it is presented a product that analyzes the local displacement gradients to generate potential damage maps in urban areas. The tools will be presented thorough some results obtained on an area of the Granada County with the use of Sentinel-1 data. All the results have been achieved within the framework of the Riskcoast Project (financed by the Interreg Sudoe Program through the European Regional Development Fund, ERDF).This work was mainly supported by the European Regional Development Fund (ERDF) through the project “RISKCOAST” (SOE3/P4/E0868) of the Interreg SUDOE Programme

Evaluation of the SBAS InSAR Service of the European Space Agency’s Geohazard Exploitation Platform (GEP)

The analysis of remote sensing data to assess geohazards is being improved by web-based platforms and collaborative projects, such as the Geohazard Exploitation Platform (GEP) of the European Space Agency (ESA). This paper presents the evaluation of a surface velocity map that is generated by this platform. The map was produced through an unsupervised Multi-temporal InSAR (MTI) analysis applying the Parallel-SBAS (P-SBAS) algorithm to 25 ENVISAT satellite images from the South of Spain that were acquired between 2003 and 2008. This analysis was carried out using a service implemented in the GEP called “SBAS InSAR”. Thanks to the map that was generated by the SBAS InSAR service, we identified processes not documented so far; provided new monitoring data in places affected by known ground instabilities; defined the area affected by these instabilities; and, studied a case where GEP could have been able to help in the forecast of a slope movement reactivation. This amply demonstrates the reliability and usefulness of the GEP, and shows how web-based platforms may enhance the capacity to identify, monitor, and assess hazards that are associated to geological processes.Spanish “Juan de la Cierva” grants support part of the work of Jorge P. Galve. The expenses related to the hired researcher contract of Jorge P. Galve and the field surveying were funded by the project CGL2015-67130-C2-1-R (FEDER and Spanish Ministry of Economy and Competitiveness)

Rapid characterisation of the extremely large landslide threatening the Rules Reservoir (Southern Spain)

When an active landslide is first identified in an artificial reservoir, a comprehensive study has to be quickly conducted to analyse the possible hazard that it may represent to such a critical infrastructure. This paper presents the case of the El Arrecife Landslide, located in a slope of the Rules Reservoir (Southern Spain), as an example of geological and motion data integration for elaborating a preliminary hazard assessment. For this purpose, a field survey was carried out to define the kinematics of the landslide: translational in favour of a specific foliation set, and rotational at the foot of the landslide. A possible failure surface has been proposed, as well as an estimation of the volume of the landslide: 14.7 million m3. At the same time, remote sensing and geophysical techniques were applied to obtain historical displacement rates. A mean subsidence rate of the landslide around 2 cm/year was obtained by means of synthetic aperture radar interferometry (InSAR) and ground-penetrating radar (GPR) data, during the last 5 and 22 years, respectively. The structure-from-motion (SfM) technique provided a rate up to 26 cm/year during the last 14 years of a slag heap located within the foot of the landslide, due to compaction of the anthropical deposits. All of this collected information will be valuable to optimise the planning of future monitoring surveys (i.e. differential global positioning systems, inclinometers, ground drilling, and InSAR) that should be applied in order to prevent further damage on the reservoir and related infrastructures.This work was mainly supported by the European Regional Development Fund (ERDF) through the project “RISKCOAST” (SOE3/P4/E0868) of the Interreg SUDOE Programme. The work of J.P.G., M.M-S., P.R. and J.M.A. was also supported by the “Ramón y Cajal” Programme (RYC-2017–23335) of the Spanish Ministry of Science, the project “MORPHOMED”—PID2019-107138RB-I00 / SRA (State Research Agency / https://doi.org/10.13039/501100011033) and the project “RADANDALUS” (P18-RT-3632) and B-RNM-305-UGR1818 of the FEDER / Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades