NH6.1 | Interferometric Synthetic Aperture Radar to assess the impacts of ground deformation in local, regional and national studies
EDI
Interferometric Synthetic Aperture Radar to assess the impacts of ground deformation in local, regional and national studies
Convener: Roberta Bonì | Co-conveners: Giulia Tessari, Alessandro Novellino, Pietro Milillo, Zherong Wu
Orals
| Wed, 17 Apr, 14:00–15:45 (CEST)
 
Room 1.14
Posters on site
| Attendance Thu, 18 Apr, 16:15–18:00 (CEST) | Display Thu, 18 Apr, 14:00–18:00
 
Hall X4
Posters virtual
| Attendance Thu, 18 Apr, 14:00–15:45 (CEST) | Display Thu, 18 Apr, 08:30–18:00
 
vHall X4
Orals |
Wed, 14:00
Thu, 16:15
Thu, 14:00
Synthetic aperture radar (SAR) is an established remote sensing tool for the mapping and monitoring of ground deformation. The new generation of radar satellite constellations (e.g., NISAR, NovaSAR) along with a big data repository of historical observations is fostering comprehensive multi-sensor hazard analyses. New constellations’ capabilities rely on innovative techniques based on high-resolution/wide-swath and short-temporal Interferometric SAR (InSAR). While acknowledging the benefits brought by these recent developments, the scientific community is now defining a new paradigm of techniques capable of extracting relevant information from SAR imagery, designing proper methodologies for specific natural and anthropogenic hazards, managing large SAR datasets (e.g., National ground motion services, Copernicus EGMS), and integrating radar data with multispectral satellite observations.
In this session, we welcome contributions that focus on:
(1) New tools and approaches such as artificial intelligence to accurately or automatically analyze InSAR large datasets and displacement time series to detect and monitor seasonal, linear and non-linear ground deformations;
(2) InSAR support for the risk assessment of anthropogenic and natural hazards including mining, oil/gas production, fluid injection/extraction, land subsidence, critical infrastructure, sinkholes, land degradation and coastal erosion, peatlands, glaciers, permafrost, flooding, landslides, earthquakes, and volcanoes;
(3) InSAR-based modeling for a better understanding of the current and future impact of ground deformation.

Orals: Wed, 17 Apr | Room 1.14

Chairpersons: Roberta Bonì, Giulia Tessari, Zherong Wu
14:00–14:05
14:05–14:15
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EGU24-4400
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On-site presentation
John F. Dehls, Marie Bredal, Ivanna Penna, Yngvar Larsen, Gökhan Aslan, Jacob Bendle, Martina Böhme, Reginald Hermanns, Vanja S. Haugsnes, and Francois Noel

Since its inception in 2018, InSAR Norway has emerged as a pivotal tool in addressing geological hazards and advancing scientific research in Norway. Utilizing the C-band data from Sentinel-1, it provides annual comprehensive ground movement updates crucial for understanding and mitigating natural disasters and ensuring infrastructure stability across Norway's complex terrain. The service's impact is particularly pronounced in landslide mapping and permafrost studies, areas of critical importance given Norway's climatic and geological vulnerability.


InSAR Norway has been instrumental in detecting and monitoring landslide-prone areas, providing data essential for early warning systems and risk assessment. Detailed morpho-kinematic inventories have been updated nationwide to include previously undetected movements. By classifying slope movements and providing velocity data, InSAR Norway has significantly contributed to understanding the kinematics of landslides, enabling more cost-effective monitoring solutions. A recent study leveraging InSAR Norway data has statistically explored the link between permafrost and displacement rates of large unstable rock slopes (LURSs), revealing that permafrost presence significantly influences these rates and that complete thawing of permafrost can reduce or halt displacement, indicating the nuanced role of permafrost in geological hazard scenarios.


InSAR Norway's data has also shed light on the dynamics of rock glaciers and permafrost creep. Studies utilizing this data have revealed the impact of permafrost thawing on rock glacier velocities and the broader implications for landscape stability and hydrology. By providing detailed movement profiles of rock glaciers in transition from active to relict stages, InSAR Norway has offered insights into the effects of climate change on cold region dynamics.


The service's free and open data policy has been central to its success, catalyzing a wide range of research and operational applications by providing unrestricted access to high-quality, high-resolution data. This policy has facilitated a collaborative environment where academics, government agencies, and industry can innovate and develop solutions to shared challenges.


With the impending integration of L-band data from the NISAR satellite mission, InSAR Norway is poised for significant enhancements. NISAR data will augment the service's ability to monitor ground movements, particularly in vegetated areas and through seasonal changes. This integration reflects our commitment to adopting cutting-edge technology to improve the accuracy, timeliness, and applicability of geohazard monitoring and research. By fusing the strengths of C-band and L-band data, InSAR Norway will provide a more comprehensive and nuanced understanding of ground deformation processes, supporting safer, more informed decision-making in the face of Norway's dynamic and often harsh environmental conditions. InSAR Norway will continue its legacy of pioneering satellite-based monitoring, safeguarding communities, and advancing scientific understanding of geohazards.

How to cite: Dehls, J. F., Bredal, M., Penna, I., Larsen, Y., Aslan, G., Bendle, J., Böhme, M., Hermanns, R., Haugsnes, V. S., and Noel, F.: InSAR Norway: Advancing Geohazard Understanding through Wide-Area Analysis, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4400, https://doi.org/10.5194/egusphere-egu24-4400, 2024.

14:15–14:25
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EGU24-8645
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On-site presentation
Giorgio Gomba, Francesco De Zan, Ramon Brcic, and Michael Eineder

The motivation for this study is to help providing a better understanding of the behavior of the earth's crust in high strain areas. High strain areas are regions of the Earth's crust, associated with tectonic plate boundaries, where the rates of ground deformation are particularly high. These areas are characterized by high seismic activity, making them of significant concern. The ability to estimate ground deformation in these regions is critical for understanding the underlying geological processes and for assessing the potential risk of future seismic events. Interferometric Synthetic Aperture Radar (InSAR) has shown great promise in delivering millimetre-scale ground displacement information over long distances across plate boundaries. In this project, we aim to globally measure ground deformation using the InSAR Persistent and Distributed Scatterer (PS/DS) technique, focusing on the regions where the second invariant of the strain is higher than 3 nanostrain per year.

Due to the large amount of data that has to be processed, we use the high-performance data analytics platform made available within the framework of the Terra_Byte project, a cooperation between the German Aerospace Center (DLR) and the Leibniz Computer Centre (LRZ). This enables us to process large volumes of data efficiently. We use the IWAP processor to apply the PS/DS technique to time-series of seven years of SAR images acquired by the Sentinel-1 mission. To improve the accuracy of our analysis and reduce the influence of ionospheric variations we use CODE total electron contents maps. The impact of solid earth tides (SETs) is limited by using the IERS 2010 convention. We use ECMWF reanalysis data to correct for tropospheric delays, which are the biggest error source and limiting factor for the interferometric performance at large distances. The influence of soil moisture and vegetation growth on distributed scatterers is limited by the full covariance matrix approach used in the interferograms generation. Finally, we calibrate and compare our results with GNSS measurements to show a detailed picture of ground deformation.

The results of this project will be publicly available on a global scale, including: velocity maps, timeseries, line-of-sight projection vectors. The product palette will allow custom calibration or 2D decomposition by the user. Possible applications are: the large coverage and homogeneous processing characteristics of the data could serve as a baseline reference or comparison for other studies. Geoscientists will be able to use the deformation measurements to gain a better understanding of geological processes, with the dense PS/DS measurements filling in the gaps between existing GNSS survey data, contributing to the advancement of scientific knowledge in this field.

How to cite: Gomba, G., De Zan, F., Brcic, R., and Eineder, M.: Mapping Worldwide Ground Deformation in High-Strain Areas with SAR PS/DS Interferometry and Sentinel-1 Imagery, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8645, https://doi.org/10.5194/egusphere-egu24-8645, 2024.

14:25–14:35
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EGU24-16229
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ECS
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On-site presentation
Yenni Lorena Belen Roa, Claudio De Luca, Manuela Bonano, Francesco Casu, Marianna Franzese, Michele Manunta, Giovanni Onorato, Pasquale Striano, Muhammad Yasir, and Riccardo Lanari

Spaceborne Differential Synthetic Aperture Radar Interferometry (DInSAR) represents a well-established technique to accurately retrieving ground surface displacements over large areas of the Earth, in both natural and anthropogenic hazard scenarios, with limited costs and with a centimeter to millimeter accuracy. However, the DInSAR technique retrieval capability may be affected by the so-called “temporal decorrelation phenomena” due to possible temporal changes of the imaged scene electromagnetic response. In this regard, the low-frequency SAR sensors, as those operating at the L-band, characterized by a significantly larger wavelength (~23 cm) with respect to the X-band (~3 cm wavelength) and C-band (~5.6 cm wavelength) ones, are particularly suited to mitigate the above-mentioned decorrelation effects, thanks to their capacity of maintaining the interferometric coherence for a long period. Moreover, these L-band SAR systems also imply considerable robustness with respect to the possible occurrence of phase unwrapping errors. These peculiarities have pushed the worldwide space agencies to invest in the development of L-band spaceborne SAR sensors as, for instance, the NISAR mission, jointly developed by NASA and ISRO, the PALSAR-3 mission of JAXA and the ROSE-L mission developed by ESA, as well as the already operative SAOCOM-1 sensors of CONAE. In this work, we focus on the Argentinean SAOCOM-1 constellation which is composed of two twins, full-polarimetric L-band SAR sensors. This system guarantees, over a large part of Europe (with a priority given to the Italian territory coverage), a systematic, DInSAR-oriented acquisition plan of SAR images in the StripMap mode, with a revisit time varying among 16, 24 and 48 days, in order to avoid coverage gaps. Moreover, we largely exploit the Parallel Small BAseline Subset (P-SBAS) approach, which is an advanced DInSAR method that allows us to effectively and efficiently generate displacement time-series with sub-centimeter accuracy. The capability of the P-SBAS algorithm to retrieve C- and X-band DInSAR time-series, relevant to both natural and anthropogenic hazard scenarios has already been widely demonstrated, as well as its capacity to perform analyses at different spatial resolution scales. Accordingly, we present here the results of the L-band SAOCOM-1 P-SBAS analysis carried out at medium spatial resolution (about 30 m) in different ground deformation scenarios affecting the Italian territory. In particular, the presented results are relevant to a portion of the Tuscany region (central Italy), which is affected by significant landslide phenomena. Moreover, we also consider the volcanic contexts of the Campi Flegrei caldera, Mount Etna and Stromboli island, all located in southern Italy. In this case, we fully benefit from the availability of GNSS measurements to provide a quantitative assessment of the retrieved L-band deformation time-series.

Finally, some SAOCOM-1 results, achieved by applying the full resolution P-SBAS approach over the urban areas of Rome and Naples municipalities, are also presented. Such a full spatial resolution (about 5 m of pixel size) analysis allows us to investigate the potentialities of the L-band data to overcome some of the limitations of the current high resolution X-band SAR systems in urbanized scenarios.

How to cite: Roa, Y. L. B., De Luca, C., Bonano, M., Casu, F., Franzese, M., Manunta, M., Onorato, G., Striano, P., Yasir, M., and Lanari, R.: A quantitative assessment of the SAOCOM-1 L-band DInSAR time-series retrieved through the P-SBAS approach in natural and anthropogenic hazard scenarios of the Italian territory, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16229, https://doi.org/10.5194/egusphere-egu24-16229, 2024.

14:35–14:45
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EGU24-14908
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Virtual presentation
Luke Bateson, Itahisa Gonzalez Alvarez, Raushan Arnhardt, Claire Fleming, Ekbal Hussain, Lee Jones, Alessandro Novellino, and Kay Smith

Hundreds of large cities worldwide are sinking; and this will get worse as by 2050 when almost 70% of the world’s population is set to live in megalopolises, the majority of these are in low lying coastal areas. At the same time sea levels are rising. According to the World Economic Forum, several of the globe’s cities, including New York, Dhaka, London and Bordeaux, could be partially or totally submerged by 2050-2100. As a city grows the environment is put under additional pressure and this often leads to subsidence. land less suitable for building upon is developed, in low lying coastal regions these areas are often poorly consolidated recent superficial deposits. Loading of such deposits causes consolidation which adds to subsidence resulting from increased groundwater abstraction required for industry and to support a growing population.

In order to mitigate against the effects of subsidence it is imperative to understand the subsidence; its location, magnitude, timing and crucially the underlying cause. InSAR offers the ability to understand the spatial extent, magnitude and timing and when integrated with in-situ data the cause can be determined. However, this interpretation process can take a significant amount of time. With the advent of continental scale InSAR data, such as the European Ground Motion Service, and automated online processing facilities such as COMETS LICSBAS system InSAR data is becoming far easier to access. This means huge volumes of data are generated and therefore automated methods are required to extract not only the areas of ground motion but also to indicate the underlying cause of the motion.

To this end we have been using integrated time series of optical and InSAR data for areas of rapid urban growth to understand the cause of subsidence. Combination of interpretations with expected patterns of subsidence derived from models of groundwater abstraction and ground loading allow us to separate subsidence signals from these causational factors. In turn this enables the generation of characteristic time series of subsidence that we would expect to see as a result of each process. Such characteristic time series form libraries that will be the basis for machine learning to automatically interpret the InSAR data.

We will present the creation of such subsidence libraries and illustrate the process with examples from Hanoi, Kuala Lumpur and Bandung. We will also present the machine learning method where a fully automated approach using Seasonal and Trend decomposition allows trends (such as stable, linear subsidence, non-linear subsidence and seasonal) within the InSAR time series to be identified and grouped into common trend behaviours. Metrics based on derived trends also allow the ‘strength’ of certain components (such as seasonal signals) to be automatically assessed.

How to cite: Bateson, L., Gonzalez Alvarez, I., Arnhardt, R., Fleming, C., Hussain, E., Jones, L., Novellino, A., and Smith, K.: Developing Machine Learning tools for the automatic interpretation of InSAR data, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14908, https://doi.org/10.5194/egusphere-egu24-14908, 2024.

14:45–14:55
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EGU24-354
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ECS
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On-site presentation
Claudia Masciulli, Giorgia Berardo, Carlo Alberto Stefanini, Michele Gaeta, Santiago Giraldo Manrique, Niccolò Belcecchi, Francesca Bozzano, Gabriele Scarascia Mugnozza, and Paolo Mazzanti

The growing accessibility of multi-sensor Persistent Scatterer (PS) data in the advent of the European Ground Motion Service offers a well-established methodology for detecting and monitoring ground displacement over extended areas with sub-centimetric precision. The detection of ground deformation phenomena relies on the available PS density, which is influenced by the sensor resolution and specific site characteristics, such as the presence of stable natural and artificial reflectors. This study proposes a novel Data Fusion (DF) approach that integrates the displacement along the line of sight of PS products to unleash the full potential of multi-sensor combinations by synthesizing multi-band displacement information. The DF approach, developed by NHAZCA S.r.l. and the Research Center “CERI - Centro di Ricerca Previsione e Prevenzione dei Rischi Geologici” of the Sapienza University of Rome in the frame of the “MUSAR” project funded by ASI (Italian Space Agency), overcomes the limitations associated with individual sensor data, allowing for improved information content and data coverage.

The method based on the strain tensor approach combines data with different orbital geometries (i.e., ascending and descending) to obtain a comprehensive deformation map by extracting synthetic measurement points called Ground Deformation Markers. In our analysis, we applied, tested, and validated the fusion method in the Basilicata region of southern Italy, combining data extracted from the C-band Sentinel-1 Copernicus initiative and the COSMO-SkyMed constellation in X-band. We evaluated the DF performance within a test site characterized by homogeneous spatial and velocity PS data distribution. The method accuracy was assessed by comparing its interpolation capabilities to estimate the velocity of deformation at a specific location with those estimated by widely used traditional (i.e., linear interpolation, cubic spline interpolation, and inverse distance weighting) and advanced techniques (i.e., universal kriging and k-nearest neighbors). The predictions of interpolators were compared with randomly extracted ground truth datasets given by the observed PS velocities. The evaluation took into consideration several metrics, such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and the coefficient of determination (R-squared). After validating the DF application, we compared multi-sensor results with single-sensor PS to assess the capability of the method to improve spatial coverage and information content, enabling a more comprehensive understanding of ground displacements. The results verified the capabilities and robustness of the DF approach and underscored its efficacy in enhancing the accuracy and spatial coverage of ground deformation monitoring. The proposed study highlighted the DF approach as a valuable tool in geospatial analysis and satellite monitoring applications.

How to cite: Masciulli, C., Berardo, G., Stefanini, C. A., Gaeta, M., Giraldo Manrique, S., Belcecchi, N., Bozzano, F., Scarascia Mugnozza, G., and Mazzanti, P.: A Novelty Data Fusion Approach for Integrating Multi-Band/Multi-Sensor Persistent Scatterers, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-354, https://doi.org/10.5194/egusphere-egu24-354, 2024.

14:55–15:05
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EGU24-13026
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ECS
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On-site presentation
Junaid Khan, Ascanio Rosi, Sansar raj Meena, and Mario Floris

Ground deformation, encompassing sudden and gradual shifts in the Earth's surface, poses significant global geohazard risks. These phenomena demand thorough investigation and monitoring and are influenced by a range of natural and anthropogenic factors such as mining, excessive groundwater extraction, seismic activities, structural loads, and subsurface geology. Our research is centered on the location in the Venetian-Friulian Plain (Veneto Region, NE Italy). This area is of interest because it represents a transitional zone where sedimentary deposits from both river systems (fluvial) and lagoon/coastal environments are found, marking the transition from the alluvial plain to the coastal plain. Ground displacement maps are generated using pre-event data from the Veneto Region Sentinel 1-PS data Service and the European Ground Motion Service (EGMS), allowing us to analyze the heightened susceptibility of areas undergoing deformation. Our approach integrates artificial intelligence techniques with InSAR-derived data to create comprehensive pre- and post-event multi-temporal deformation inventories and susceptibility maps. This fusion offers exceptional accuracy and timeliness in identifying, modeling, and predicting ground deformation events. Utilizing insights from InSAR data and AI techniques, we aim to project future trends and potential risks, contributing valuable insights to geohazard assessment and management within the study region.

How to cite: Khan, J., Rosi, A., Meena, S. R., and Floris, M.: The Role of Artificial Intelligence in Modeling and Predicting Ground Deformation Using Advanced InSAR Data, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13026, https://doi.org/10.5194/egusphere-egu24-13026, 2024.

15:05–15:15
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EGU24-6191
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On-site presentation
Camilla Medici, Alessandro Novellino, Claire Dashwood, and Silvia Bianchini

In recent years, satellite-SAR interferometry has established itself as a widely used global monitoring technique, enabling timely detection, monitoring and mitigation of both natural disasters and human-induced ground movements. When dealing with large multi-temporal InSAR data, the ground deformation detection becomes a fundamental and complex task with the consequent pressing need to establish new approaches and tools for effectively analysing large interferometric datasets. The advanced capabilities of the satellite systems and the continuously updated processing techniques provide unprecedented amounts of data to analyse the ground deformation processes for large territories in reduced time frames. Within this context, the fast detection and characterization of the ground deformation processes constitute a milestone for what concerns the correct management and mitigation of their impact on vulnerable populations and infrastructures. As a result, the starting point for all ground deformation detection and monitoring techniques is to work with updated inventories, a fundamental yet often overlooked issue in most countries such as Great Britain. Despite the availability of a national landslide database, less than half of the landslides reported are mapped as polygons, and their state of activity is unknown. In this regard, in this work we updated the national landslide inventory by mapping new events or simply identifying their current condition of motions through the use of the data freely provided by the European Ground Motion Service (EGMS), which represents an unprecedented baseline for ground deformation applications at continental, national and local level with millimetre accuracy. The approach relies on a semi-automatic tool, recently developed at the Centre Tecnològic de Telecomunicacions de Catalunya to identify the Active Deformation Areas (ADAs). Following an initial analysis of the InSAR data, the tool allows the identification of unstable areas characterized by a minimum number of persistent scatterers with velocity values over a specific threshold. The results consist of two ADA maps corresponding to the two Sentinel-1 velocity components and, subsequently, the output can be combined with landcover and topographic maps. The study has been carried out by exploiting the horizontal and vertical velocity maps provided by the EGMS which has enabled a national-scale analysis. Subsequent steps involve the classification and temporal analysis of the identified ADAs, followed by the analysis of more relevant local case studies. 

How to cite: Medici, C., Novellino, A., Dashwood, C., and Bianchini, S.: Semi-automatic analysis of InSAR large datasets for landslide mapping and monitoring: the Great Britain case study, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6191, https://doi.org/10.5194/egusphere-egu24-6191, 2024.

15:15–15:25
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EGU24-1130
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On-site presentation
Aparna Raman and Chandrakanta Ojha

Coastal Subsidence is a complex phenomenon with large spatiotemporal variability to natural processes and anthropogenic activities, leading to the potential inundation risk of major coastal cities worldwide with the increase in relative sea level rise and shoreline sinking (Shirzaei et al., 2021). India’s coastal metro-politician cities are vulnerable to future inundation risk due to the rising sea level. Kerala, a southern state in India with about 590 km of coastline covering vast habitats of rich biodiversity and occupants, has faced the impacts of coastal subsidence for the past few decades. There is a wide scope of detail investigating Kerala’s coastal land subsidence and its impact due to the rise in sea level using geodetic techniques. In this context, we explored the data from Sentinel-1 of ESA acquired along the descending track (Path 63 and 165) with a VV polarization for monitoring subsidence. The Vertical Land Motion (VLM) is analyzed using the Small BAseline Subset (SBAS) based MT-InSAR technique along the entire coastline of Kerala which is spread across 590 km (Berardino et al., 2002). A total of 1443 interferograms were generated by co-registering 326 single-look complex images and applying a spatial baseline threshold of 85 m and a temporal baseline threshold of 65 days. The result shows that most regions in Kerala are subsiding at a rate of > 5mm/year, with the Kuttanad region of Alappuzha showing a maximum subsidence of > 20mm/year. The tide gauge station of Kochi Willingdon Island shows a relative sea level trend of 1.97±mm/year. NASA’s Intergovernmental Panel on Climate Change (IPCC) AR6 report has projected a future sea level change of 0.71 meters by 2100, considering the socioeconomic scenario SSP3-7.0. The InSAR-derived VLM, projection data of sea level from the IPCC-AR6 report, and the high spatial resolution of the Digital Elevation Model (DEM) have been incorporated to map the low-lying fast subsiding zones that are prone to future flood inundation due to relative sea level rise for all the 14 districts of Kerala. We further aim to incorporate a U-net-based deep learning model to efficiently handle these terabytes of data and develop more accurate inundation maps. This study will be helpful for policymakers to take precautionary measures to prevent future inundation hazards over the shoreline. 

 

References

Shirzaei, M., et al. (2021). "Measuring, modelling and projecting coastal land subsidence." Nature Reviews Earth, Environment 2(1): 40-58.

 

Berardino, P., G. Fornaro, R. Lanari, and E. Sansosti, (2002). "A New Algorithm for Surface Deformation Monitoring Based on Small Baseline Differential SAR Interferograms." IEEE Transactions on Geoscience and Remote Sensing 40 (11): 2375–83. https://doi.org/10.1109/TGRS.2002.803792.

 

How to cite: Raman, A. and Ojha, C.: Impact analysis of Relative Sea Level Rise in the entire Kerala Coast of India using MT-InSAR Technique, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-1130, https://doi.org/10.5194/egusphere-egu24-1130, 2024.

15:25–15:35
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EGU24-19174
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ECS
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On-site presentation
Serena Rigamonti, Giuseppe Dattola, Matteo Oryem Ciantia, and Giovanni Battista Crosta

Underground gas storage (UGS) is of strategic importance both in terms of security of supply and to ensure the operational continuity of primary industrial basins. UGS reservoirs make it possible to guarantee the country a continuous and reliable supply of natural gas. It is well known that UGS activities can induce ground deformations, in response to gas injection and extraction cycles. The Lombardy region (Italy) has a predominant part in the Italian national policy of UGS in depleted reservoirs. In this work, five UGS reservoirs located in Lombardy and three additional ones in Italy, which differ in geometric and geo-lithological features, were considered.

In this context, the InSAR (Interferometric Synthetic Aperture Radar) technique plays a key role in monitoring ground deformations induced by UGS activities, providing precise measurements of ground displacement.

In this contribution, we present (i) an application of a multi-method approach for the analysis of trends and seasonal signals in the EGMS InSAR time series of ground displacements in the proximity of UGS reservoirs to recognise specific footprints and spatial-temporal patterns of ground deformation. For this purpose, large datasets of ground displacements covering the UGS area in Lombardy (25 km2) from 2015 to 2022 were analysed; and (ii) an interpretation of the possible causal relationship between displacement and gas injection and extraction time series using cross-correlation approach and wavelet tools in the time-frequency domain.

The multi-method approach involves the application and optimization of Principal Component (PCA) and Independent Component Analyses (ICA) in temporal (T-) and spatial (S-) modes on both ascending and descending InSAR time series, as well as on the vertical and horizontal ones, allowing for a spatial-temporal separation of the original data into a set of limited components. Among them, it is possible to isolate those related to the USG deformations, from other signals typical of the region. Subsequently, clustering analysis is performed to group the InSAR time series and identify characteristic ground deformation patterns, which could also be related to differences in grain size properties.

As a result, it was possible to recognize and separate a limited number of signal components, describing long-term displacement and seasonal fluctuations, and the derived maps allowed the characterization of the area of influence relative to each UGS reservoir. Finally, cross-correlation approach and wavelet tools made it possible to identify and interpret the time lag between the peaks and, consequently to improve the correlation between displacements and anthropogenic triggers.

To validate the deformation patterns resulting from the approach, numerical analyses were performed in which the gas injection and extraction time series were considered as input variables. 

How to cite: Rigamonti, S., Dattola, G., Ciantia, M. O., and Crosta, G. B.: A multivariate time series analysis of underground gas storage deformations using InSAR data, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19174, https://doi.org/10.5194/egusphere-egu24-19174, 2024.

15:35–15:45
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EGU24-8610
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ECS
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On-site presentation
Gabriele Fibbi, Tommaso Beni, Matteo Del Soldato, and Riccardo Fanti

The importance of natural gas in meeting human energy needs persists, even amid the ongoing global energy transition. Fossil fuels, including coal, oil, biomass, and natural gas, remain central for providing essential energy services such as cooking, heating, and electricity generation for homes and businesses. Despite the increasing emphasis on renewable energy sources, total reliance on electricity is not yet feasible, necessitating a transitional phase wherein natural gas will play a key role. Natural gas, particularly in the form of methane (CH4), remains an indispensable resource due to its efficiency and versatility. This is particularly evident during periods of increased energy demand, such as the winter season, when natural gas serves as a reliable source for heating and power generation. The importance of a steady and uninterrupted supply of natural gas is highlighted by the challenges posed by seasonal fluctuations in demand. In response to the dynamic energy landscape, Underground Gas Storage (UGS) facilities have gained prominence as a strategic solution. With 160 active projects in Europe at the end of 2021, UGS activities provide the flexibility to store and deliver natural gas continuously, adapting to daily and seasonal fluctuations. This adaptability is critical to maintain a stable energy supply, especially during peak demand periods. On the other hand, UGS cycles have the potential to induce three-dimensional deformations within the affected reservoir that are subsequently transmitted to the surface. These deformations should be monitored since they can compromise the integrity of wells and nearby infrastructure. In this context, Interferometric Synthetic Aperture Radar (InSAR) is emerging as a valuable tool for continuous monitoring ground displacement resulting from UGS activities. InSAR analysis can provide millimetre-precision measurement points, overcoming the spatial coverage of in-situ instruments. The Yela site exploits a fractured aquifer reservoir located in the Madrid Basin (Spain) currently employed for UGS activities by Enagás, the Spanish main Transmission System Operator. A correlation between long-term records of gas volume (2019-2022) with vertical and horizontal (E-W) ground displacement data (2015-2020) from the European Ground Motion Service (EGMS) and the UGS activity rates can be established. The temporal evolution of vertical ground displacement shows a clear sinusoidal signal aligned with the amplitude and periodicity of the load/discharge curve of natural gas in the reservoir. This result highlights the versatility of the InSAR approach for UGS monitoring, complementing in-situ data, enhancing safety and improving facility management. In addition, InSAR technology can allow continuous monitoring analysis for detecting changes in the UGS environment, for risk management purposes and calibration of geomechanical models useful for estimating maximum pressure values. This work introduces a replicable approach to investigate freely available ground movement data, presenting a comprehensive comparison of InSAR results for the Yela UGS site. Leveraging open-source and easily accessible data, the study offers insights into the volumetric variation model and it identifies a significant correlation between natural gas injection/withdrawal rates and InSAR ground displacement over time.

How to cite: Fibbi, G., Beni, T., Del Soldato, M., and Fanti, R.: EGMS insights into ground deformation patterns in Underground Gas Storage (UGS) activities, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8610, https://doi.org/10.5194/egusphere-egu24-8610, 2024.

Posters on site: Thu, 18 Apr, 16:15–18:00 | Hall X4

Display time: Thu, 18 Apr, 14:00–Thu, 18 Apr, 18:00
Chairpersons: Giulia Tessari, Zherong Wu, Alessandro Novellino
X4.57
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EGU24-6112
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ECS
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Highlight
Pouya Ghezelayagh, Ryszard Oleszczuk, Marta Stachowicz, Mohammad Reza Eini, Piotr Banaszuk, Andrzej Kamocki, and Mateusz Grygoruk

Peatlands are vital ecosystems that provide essential ecological services, especially in carbon storage. Nevertheless, the decomposition of surface peat and subsequent carbon emission threaten to accelerate the pace of climate change. This study presents a framework designed to facilitate the estimation of peat subsidence and relevant CO2 emissions through the exclusive utilization of remote sensing techniques. In this study, the peatland subsidence in the Biebrza Valley, Poland, was estimated by using the Alaska Satellite Facility Interferometry Synthetic Aperture Radar on-demand cloud computing via a Small Baseline Set technique and seasonal-annual search approach covering the period from April 2015-April 2022. The amount of subsidence and associated carbon emission rates can be estimated by analyzing InSAR data from a selected period. The results reveal an annual peatland subsidence rate of 2.1 cm, verified through field surveys. An R2 value of 0.91, and an RMSE value of 0.23 cm indicate the reliability of this approach in estimating the subsidence. These findings unveil a troubling trend in the Biebrza National Park, with almost 88 MCM of its peatlands lost during the seven years from 2015-2022. Two different approaches were employed to estimate CO2 emissions associated with subsidence, each with three scenarios. Therefore, the estimation of annual peatland carbon dioxide loss, ranging from 3.24 to 5.36 tons per hectare through the remote sensing-based approach, compared to the broader range of 20.3 to 33.9 tons/ha/yr obtained from the common approach. It means that, based on the first approach, in the most optimistic scenario, the park is associated with a minimum of 1.35 million tons of carbon dioxide emissions during this period, potentially reaching as high as 2.26 million tons in the worst-case scenario. In contrast, the common approach indicates a wider range of emissions, ranging from 8.5 to 14.2 million tons over these years.

How to cite: Ghezelayagh, P., Oleszczuk, R., Stachowicz, M., Eini, M. R., Banaszuk, P., Kamocki, A., and Grygoruk, M.: A remote-sensing-based framework to detect the rate of peat subsidence and associated CO2 emissions: A case study of the Biebrza Valley, Poland, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6112, https://doi.org/10.5194/egusphere-egu24-6112, 2024.

X4.58
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EGU24-8369
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ECS
Jhonatan Steven Rivera Rivera, Marta Béjar Pizarro, Héctor Aguilera Alonso, Pablo Ezquerro, Carolina Guardiola-Albert, and Oriol Monserrat

InSAR has been widely employed in terrain deformation analysis worldwide. Its significant utility in risk management has led to the development of extensive SAR databases, poised for exploration in land-use planning studies. However, this information still requires specific expertise, hindering its accessibility for non-expert users. In this work, we introduce MOVESAR, an SAR-based database designed for training Machine Learning (ML) classification models capable of providing precise information on the type of deformation process and its cause. MOVESAR is also planned to support the development of deformation time series forecasting models.

Each row in MOVESAR is spatiotemporally linked to a deformation time series (DTS) obtained through InSAR processing of SAR images from various satellites (SENTINEL 1, ENVISAT, ERS, COSMO-SkyMed, ALOS and TerraSAR-X), collected from previous studies conducted by the Geological Survey of Spain (IGME) and the Centre Tecnológic Telecomunicacions Catalunya (CTTC). Spatially, our database covers a substantial part of the Spanish territory, represented in 60 deformation polygons (with more than 300,000 measurement points or "MPs"), spanning from 1992 to 2020.

Each column in MOVESAR represents a covariate potentially related to the six deformation processes compiled in this initial version of the database: piezometric change-induced deformation, landslide in mining environments, soil landslide, constructive subsidence, subsidence in mining environments, and subsidence in dumps. Covariates include geological, morphometric, hydrological, and geotechnical information, as well as data associated with DTS, land use, land cover, and landslide, subsidence and expansive clays susceptibility/hazard. Dynamic variables, including precipitation and DTS, underwent transformation into static variables by extracting statistical measures such as mean, standard deviation, range, and slope.

In this study, we present preliminary results from nine ML models trained using MOVESAR: four single base models (nb, knn, lda, and lr), and five ensemble models (rf, gbc, xgboost, lightgbm, and catboost). We discuss the performance of the models and analyze the importance of covariates. Additionally, we evaluate the impact of applying techniques aimed at reducing noise, bias, and model complexity, such as threshold velocity filtering technique (TVF) for eliminating stables MPs, Recursive Feature Elimination (RFE) for covariate reduction, and Cost Sensitive Learning (CSL) for class balancing.

Our future work aims to expand the number of covariates, MPs, and classes using the European Ground Motion Service (EGMS) to enrich MOVESAR, establishing it as a nationally valuable database for forthcoming studies on geohazard management. Additionally, we plan to apply spatiotemporal Deep Learning (DL) models incorporating dynamic variables, providing reliable classifications for decision-making in urban planning and national land-use management.

This work has been developed thanks to the pre-doctoral grant for the Training of Research Personnel (PRE2021-100044) funded by MCIN/AEI/10.13039/501100011033 and by "FSE invests in your future" within the framework of the SARAI project "Towards a smart exploitation of land displacement data for the prevention and mitigation of geological-geotechnical risks" PID2020-116540RB-C22 funded by MCIN/AEI/10.13039/501100011033.

How to cite: Rivera Rivera, J. S., Béjar Pizarro, M., Aguilera Alonso, H., Ezquerro, P., Guardiola-Albert, C., and Monserrat, O.: Automated classification of ground deformation processes in Spain: a machine learning approach using a novel national InSAR-based database, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8369, https://doi.org/10.5194/egusphere-egu24-8369, 2024.

X4.59
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EGU24-9924
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ECS
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Francesca Grassi, Francesco Mancini, Veronica Dallari, Elisa Bassoli, and Loris Vincenzi

The recent and planned launch of high-resolution and short revisit time Synthetic Aperture Radar (SAR) satellite missions, along with the use of advanced multi-temporal interferometric techniques, has opened up new possibilities in the field of structure and infrastructure monitoring. The cited techniques are capable of providing displacement time series of stable targets at the ground with millimetre accuracy. They are particularly relevant for preventive conservation, maintenance, and health assessment of existing built heritage.
A method for reconstructing the 3D rigid motion of isolated buildings from a dual-orbit set of SAR data has recently been proposed by the authors. In that work, the assessment of the significance of the computed motion components has received particular attention due to the low entity of displacement that could potentially affect the buildings. The method was tested on COSMO-SkyMed SAR data processed using an open-source procedure. The results indicate that it is possible to detect displacements in the order of a few mm/yr and rotations in the order of mrad/yr with corresponding uncertainties that are one order of magnitude smaller than the associated parameters.
This work combines the proposed structural investigation method with a Geographic Information System (GIS) dataset to develop a methodology for assessing building stability at an urban extent. GIS layers were used to define the spatial relation between scatterer locations and building shape, detecting targets belonging to buildings and retrieving the precise heights of the scatterers. The 3D rigid motion analysis was conducted for all individual buildings in the area with relevant uncertainties assessment. The workflow is able to map the potential stability issues of single buildings, at urban extent, as starting point for further investigation.
The methodology has been tested on the city of Modena (Italy) and GIS layers representing the classification of building stability is presented.
Funding: The methodology adopted in the present research was partially developed in the frame of the Progetti di Rilevante Interesse Nazionale (PRIN) 2022 DAMAGE “Damage Analysis and Monitoring of Ancient structures interacting with Geotechnical Excavations”, contract E53D23002550006.

How to cite: Grassi, F., Mancini, F., Dallari, V., Bassoli, E., and Vincenzi, L.: Mapping the buildings stability at urban extent based on MT-InSAR and 3D rigid motion reconstruction method, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9924, https://doi.org/10.5194/egusphere-egu24-9924, 2024.

X4.60
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EGU24-10088
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ECS
Michael Rudolf, Katrin Krzepek, Benjamin Homuth, Dorota Iwaszczuk, and Andreas Henk

The uplift and subsidence of the earth's surface can be attributed to many different processes. In urban regions in particular, it is important to understand which ground movements occur, whether they pose a risk to infrastructure and whether countermeasures can be taken. While events such as earthquakes, sinkholes and landslides have abrupt and visible effects, slow ground movements such as slope instabilities and tectonic movements are difficult to detect and it can take decades for visible damage to occur. Remote sensing, especially InSAR and Persistent Scatterer InSAR, provides high spatial and temporal coverage for monitoring these processes. The state of Hesse in central Germany is confronted with various ground movements, including former open-cast lignite mines, active salt mining and landslide-prone geological units. Our study aims to explore previously unknown ground movements in urban regions using remote sensing, analyse detected areas, determine causes, assess risks and anticipate future developments. We use Persistent Scatterer Interferometry (PS-InSAR) data from the Ground Motion Service Germany (BBD) to analyse ground motion patterns. With the help of a Ground Motion Analyser (GMA), time series analysis and external data, we identify regions with significant ground movements throughout the federal state. A case study in Frankfurt am Main, located on the northern edge of the Upper Rhine Graben, shows subsidence that was probably caused by groundwater extraction during the construction of buildings. Another case study in Crumstadt, in the centre of the northern Upper Rhine Graben, shows pronounced seasonal fluctuations, possibly related to temperature and activity in an underground gas reservoir. In both cases, an analysis of external data such as groundwater levels, climate data, construction activity, mining activities, hydrogeological and geological conditions must be taken into account. The ground movements caused by the various possible causes can sometimes be very similar, so a solid external database is particularly important. With the help of the results, the ground movements measured by remote sensing can be linked both qualitatively and quantitatively with the regional conditions. Our results thus contribute to understanding and mitigating the effects of ground movements and underline the importance of analysing both time-varying movements and linear velocities in parallel with external data.

How to cite: Rudolf, M., Krzepek, K., Homuth, B., Iwaszczuk, D., and Henk, A.: Inversion-based Time Series Analysis of PS-InSAR Data: Uncovering the Origins of Subsidence and Annual Fluctuations in Southern Hesse, Germany, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10088, https://doi.org/10.5194/egusphere-egu24-10088, 2024.

X4.61
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EGU24-17444
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ECS
Artur Guzy, Magdalena Łucka, and Wojciech Witkowski

Mining, a critical global economic activity, disturbs the geomechanical and hydrogeological equilibrium of aquifer systems. This disturbance becomes particularly evident after mining operations cease. In post-mining areas, one of the most significant phenomena is the groundwater rebound. This process restores original groundwater levels in depleted mines, leading to land uplift and the formation of sinkholes. Such changes can be detrimental to infrastructure and pose a threat to public safety. These complex dynamics necessitate continuous monitoring of ground movements to mitigate potential hazards effectively. Interferometric Synthetic Aperture Radar (InSAR) technology has emerged as a valuable tool in this context, providing detailed insights into land movements. However, the complex geological, hydrogeological, and mining conditions in post-mining areas demand advanced InSAR data processing techniques to detect early signs of phenomena such as sinkholes, thereby enhancing our ability to respond to these geohazards.
Our study was conducted in the historical zinc and lead mining region near Olkusz, northeast of Krakow, Poland. This area, with a long history of underground mining, witnessed the conclusion of its mining operations in 2022. Since then, significant land surface deformations and sinkholes have been observed, impacting both rural and urbanized areas. To understand these land movements, our approach involved two primary methods: Persistent Scatterer Interferometric Synthetic Aperture Radar (PS InSAR) for long-term analysis and Differential InSAR (DInSAR) for short-term changes, employing ESA Copernicus Sentinel-1 data. For long-term land surface movement analysis, we analyzed 165 radar images from January 2020 to June 2023, captured using ascending orbital geometry. The data acquisition frequency varied due to changes in satellite operations. Short-term land surface movements were examined through 54 interferograms covering various time intervals (12-24-36 days) between July and December 2023, using both ascending and descending geometries.
We observed a complex pattern of land movement in the study area, with both subsidence and uplift. The average movement rates varied from -14.5 mm/year to +7.7 mm/year, with about 90% of the area experiencing changes within ±2.0 mm/year. The closed zinc and lead mine region showed significant uplift, reaching up to +7.7 mm/year, highlighting pronounced geomechanical changes. Seasonal movements, with amplitudes of ±15 mm, were dominated by winter-summer variations. A positive linear trend across a considerable portion of the study area suggests widespread land uplift since early 2022. The accuracy of the DInSAR method was approximately ±2 cm, while PSInSAR achieved finer resolution at ±0.5 cm. Short-term changes indicated potential ongoing terrain deformation, especially in shorter-time base interferograms. However, confirming these observations was challenging due to low signal quality in longer intervals. The impact of vegetation on DInSAR signal quality, particularly in forested areas, underscored the need for improved methodologies.
This study enhances our understanding of aquifer system deformation mechanisms in post-mining areas. The use of InSAR techniques, particularly in urbanized regions, is crucial for the effective monitoring of ground movements, highlighting the importance of ongoing research to refine interferometric calculation efficiency, especially in areas with dense vegetation and urban structures.

How to cite: Guzy, A., Łucka, M., and Witkowski, W.: Advancing InSAR Applications in Detecting Land Movement and Sinkhole Precursors in Post-Mining Landscapes, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17444, https://doi.org/10.5194/egusphere-egu24-17444, 2024.

X4.62
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EGU24-18009
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ECS
Rainer Gardeweg, Tamara Mathys, Martin Hoelzle, and Simon Allen

In a time of increasing global warming and interconnected environmental changes, the assessment and detection of moving landforms are of growing importance for implementing successful adaptation and mitigation strategies concerning geohazards. Understanding the factors and processes governing slope movements, as well as their annual and seasonal variability, is of crucial significance. In recent years, advances in remote sensing applications and the availability of satellite data have been made, leading to an increased use of remotely sensed data for hazard monitoring and detection. Additionally, the use of machine learning enables the application of these methods to larger areas. Here, we concentrate on the Ala Archa catchment in Kyrgyzstan (Central Asia), located approximately 40 kilometres south of the capital city Bishkek, with a long history of glacier monitoring at Golubin Glacier.


This study aims to identify the predominant environmental factors influencing slope movements within the Ala Arch catchment and investigates the contribution of variations in environmental conditions to annual fluctuations in slope movement. We first present an average velocity map for the area of interest using InSAR (Interferometric Synthetic Aperture Radar) with Sentinel-1 data from both ascending and descending orbits between 2018 and 2023. The data is processed using ISCE (InSAR Scientific Computing Environment) and MintPy (Miami InSAR Time-series software in Python). Additionally, we use statistical modelling to estimate the influence of selected environmental variables such as relief, permafrost distribution, vegetation cover and landform classification. To determine the influence on seasonal/annual variations, we incorporate fluctuating variables like air temperature, precipitation and the duration of snow cover. In a final step, we examine how the identified relationships can be applied to generate an upscaled regional susceptibility map for slope movement.


In conclusion, our objective is to demonstrate the potential use of openly available satellite data for detecting hazardous or moving areas in regions where in-situ measurements are impractical or the necessary resources are unavailable.

How to cite: Gardeweg, R., Mathys, T., Hoelzle, M., and Allen, S.: Correlation between environmental variables and slope movements in the Ala Archa catchment, Kyrgyzstan, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18009, https://doi.org/10.5194/egusphere-egu24-18009, 2024.

X4.63
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EGU24-14387
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ECS
Nicușor Necula and Mihai Niculita

The European Ground Motion Service (EGMS) products expand the InSAR utility in geohazards investigation, including mapping and monitoring various surface processes such as land subsidence, volcanic activity, landslides, etc. Access to such data is crucial, particularly for urban areas needing continuous monitoring of structures and infrastructures affected by landslides. Landslide deformations have become a significant threat in the context of climate change and global urbanization nowadays. The EGMS products offer consistent and reliable InSAR measurements of ground deformations with millimeter accuracy, which can be accessed and downloaded from the platform. The measurements include GNSS-calibrated full-resolution velocity and displacement time series for the ascending and descending orbits and calculated displacement vectors in the vertical and E-W directions, resampled to a 100 x 100 m grid. We focus on the slow-moving landslides with typical velocities of 16 mm/year, specific to the Moldavian Plateau, Eastern Romania. We exploit the ascending and descending full-resolution data for the 2016 – 2022 interval to identify the active landslides. Based on an existing landslide inventory extracted from high-resolution LiDAR DEM, we analyze the moving landslide of the current inventory.

How to cite: Necula, N. and Niculita, M.: Active landslides inventory update based on EGMS data for slowing moving landslides in a hilly environment, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14387, https://doi.org/10.5194/egusphere-egu24-14387, 2024.

X4.64
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EGU24-860
Çağkan Serhun Zoroğlu, Tülay Kaya Eken, Emre Havazlı, Quentin Bletery, and Haluk Özener

Abstract

Türkiye has a complex tectonic structure resulting from the northward movement of the African and Arabian plates towards the Anatolian plate relative to the Eurasian plate. Seismic energy is primarily released within the Anatolian plate by earthquakes along the North Anatolian Fault Zone (NAFZ), which is oriented east-west with a right-lateral strike-slip motion. Historical earthquake records suggest a westward migration of seismic energy release along this fault system through a series of earthquakes, beginning with the 1939 M7.9 Erzincan earthquake and culminating in the 1999 M>7 Izmit-Düzce ruptures. The 1999 Mw7.2 Düzce earthquake occurred three months after the 1999 Mw7.4 Izmit earthquake to the east leading to an eastward supershear rupture. We examine the potential correlation between crustal features, fault mechanisms, and inter-seismic loading parameters that impact surface deformation in Düzce. We analyzed spatio-temporal variation of the long-term surface deformation along the Düzce segment. We evaluated Sentinel-1 InSAR data for both ascending and descending orbits from 2014 to 2022, utilizing the InSAR Small Baseline Subset time series analysis technique to calculate horizontal and vertical displacements and the locking depth. Our findings indicate 25 mm/yr of slip rate on the Düzce Fault. We further utilize the previously estimated geoelectric characteristics of the crust by magnetotelluric data modeling that show strong resistivity variations from east to west on the Düzce rupture. Incorporating geodetic (e.g., InSAR-derived surface deformation) and geophysical (electrical resistivity, seismic velocity) constraints on the fault zone and its adjacent shed light on the impact of the physical characteristics of the crustal structure on the inter-seismic loading and surface creep parameters.  

This project is funded by the Bogazici University with the BAP Project No SUP-18161.

How to cite: Zoroğlu, Ç. S., Kaya Eken, T., Havazlı, E., Bletery, Q., and Özener, H.: Spatiotemporal variation in surface deformation of the North Anatolian Fault Zone in the Düzce Region by Geodetic and Geophysical techniques, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-860, https://doi.org/10.5194/egusphere-egu24-860, 2024.

X4.65
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EGU24-14488
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ECS
Bahruz Ahadov, Fakhraddin Kadirov, and Eric Jameson Fielding

The decreasing sea level of the Caspian Sea is having a serious impact on coastal ecosystems and biodiversity. This study, conducted over a decade from 2014 to 2023, provides a comprehensive analysis of the coastal transformations in the Gizil-Aghaj State Reserve, Azerbaijan, using remote sensing technologies. By utilizing a combination of optical and radar satellite data, we mapped the evolving interplay between land and sea. Our research reveals a significant coastline shift, with the Caspian Sea receding to expose an additional 218 km2 of land. This significant change was most apparent in the northeastern area, corresponding with regions experiencing substantial land subsidence. As the Caspian Sea's level decreases and the land sinks simultaneously, it's reasonable to expect that the shoreline would remain stable. In contrast to areas with land subsidence, places where the land is uplifting, along with the Caspian Sea's decreasing level, are likely to experience noticeable changes in their shoreline, suggesting a more dynamic and changing coastal area. These findings are crucial for understanding the fluctuations in the Caspian Sea level, likely influenced by a combination of natural geological processes, human activities, and broader climatic trends. The subsidence observed in some areas may be due to tectonic movements or human activities such as resource extraction. In difference, the uplift seen in other areas, where there is evidence of building up over time, might be influenced by both anthropogenic factors and natural tectonic processes. Moreover, our study highlights the intricate relationship between coastal dynamics, vertical land movements, and environmental changes. It highlights the critical need for integrated and multi-dimensional monitoring approaches to address these complex interactions. These results not only contribute to a deeper understanding of the Gizil-Aghaj State Reserve's coastal ecosystem but also offer valuable perspectives on the Caspian Sea's response to climate change. Such insights are crucial for developing adaptive strategies for coastal management and conservation in an era marked by environmental uncertainties and changes.

How to cite: Ahadov, B., Kadirov, F., and Fielding, E. J.: Caspian Sea Level Changes and Coastal Dynamics: A Case Study of the Gizil-Aghaj State Reserve Using Multi-Sensor Satellite Data, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14488, https://doi.org/10.5194/egusphere-egu24-14488, 2024.

X4.66
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EGU24-9907
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ECS
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Highlight
Monitoring Land Subsidence in Kathmandu Valley, Nepal
(withdrawn after no-show)
Sanjeev bickram Rana, Bhogendra Mishra, Nabin Tiwari, Bhaskar Khatiwada, Anoj Khanal, Prabin chandra Kc, Kabiraj Rokaya, and Ganesh Dhakal

Posters virtual: Thu, 18 Apr, 14:00–15:45 | vHall X4

Display time: Thu, 18 Apr, 08:30–Thu, 18 Apr, 18:00
Chairpersons: Alessandro Novellino, Pietro Milillo, Zherong Wu
vX4.33
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EGU24-14836
Avadh BIhari Narayan, Shouvik Bhattacharjee, and Ashutosh Tiwari

Multi-temporal SAR Interferometry (MT-InSAR) is one of the widely used modern geodetic techniques for monitoring the surface deformation. By using the spatio-temporal analysis of a stack of differential interferograms,  MT-InSAR measures the time series deformation pattern. The analysis separates the deformation component from decorrelation noise, atmospheric error, and inaccurately modelled nuisance parameters. In the initial phase of the development of MT-InSAR approach, only highly coherent pixels, called the persistent scatterers (PS), were used for deformation monitoring. Highly coherent pixels are mostly found either in the urban regions or on the slopes facing the satellite. To estimate the deformation pattern in other regions, moderately coherent pixels, called distributed scatterers (DS), are used. However, before applying spatio-temporal analysis to estimate deformation, the phase information of DS pixels needs to be optimized by the phase triangulation algorithm (PTA).

We have developed a software Multi-temporal InSAR for deformation study (MInDS), which uses a similar environment as stamps use.  The processing chain of the MInDS processing chain is based on Similar Time-series Interferometric Pixels (STIP), representing the number of neighborhood pixels with similar phase history. In this approach, PS selection and estimation of look angle error is improved by using STIP of the PS pixels. After the selection of PS, the PTA implemented by using complex least squares utilises the phase information of neighboring STIPs to improve the phase coherence of DS pixels. Finally, the deformation pattern of the PS and phase-optimized DS pixels are used for deformation estimation using spatio-temporal analysis.

How to cite: Narayan, A. B., Bhattacharjee, S., and Tiwari, A.: Multi-temporal InSAR for deformation study (MInDS): A software for deformation monitoring, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14836, https://doi.org/10.5194/egusphere-egu24-14836, 2024.