Conference Agenda

Since 2020, in the framework of the ESA-MOST Dragon-5 project, the National Institute of Geophysics and Volcanology (INGV) from Italy, Northeastern University (NEU) and Jilin Earthquake Agency from China conduct collaborative have researched on the multiple mining-induced geohazards in Northeast China and Changbaishan active volcano (Jilin Province, ~300 km east from Shenyang) using time Series SAR images, and made a series of fruitful research results.

Our first study site is the Fushun west Opencast coal mine (FWOCM), located in the southwest of Fushun city, China, which is the largest opencast mine in Asia. Since the 1920s, more than 90 landslides have been reported in FWOCM, especially the huge landslide on the south slope, which named Qiantaishan landslide. The Qiantaishan landslide has experienced a fast moving period during 2013 to 2016, and has stabilized since 2017. During the fast moving period, the landslide mass has moved approximately 90 meters. However, since 2017, displacements of the Qiantaishan landslide is less than 150 mm/year. In order to analyze the spatial pattern and temporal evolution of FWOCM landslide and surrounding urban areas, both MT-InSAR and multi-temporal pixel offset tracking have been performed. Multi-temporal pixel offset tracking has been conducted considering 53 Cosmo SkyMed SAR images collected from 2013-07-03 to 2016-12-18 for the descending track, to monitor displacement of the fast moving period of Qiantaishan landslide. The results show that the landslide moves very fast during 2014, and slows down during 2015 to 2016. The MT-InSAR analysis has been carried out based on Sentinel-1 images collected during 2017 to 2022, to track the slow-moving period of Qiantaishan landslide. MT-InSAR results highlight that the displacements rate of the Qiantaishan landslide is up to 150 mm/year, which has basically stabilized. Moreover, the monitoring results show that a subsidence basin appeared in the urban area near the eastern part of the north slope in 2018, with settlement center located at the intersection of E3000 and fault F1. Comparison with ground measurements and cross correlation analysis via cross wavelet transform with monthly precipitation data are also computed, to analyze the influence factors of displacements in FWOCM.

The second study site is the Dagushan Iron Mine, located in Anshan City, China, which is one of the deepest open-pit iron mines in Asia. The iron ore mining pit is located in the western part of the mining area. With the continuous increase of mining depth, the height and angle of the pit slope continue to increase, and the stability of the slope decreases, thereby affecting the safety production of the mine. After experiencing continuous rainfall in the summer of 2017 and 2018, the Dagushan Iron Mine experienced a large-scale landslide in September 2018. For the slope stability monitoring of open-pit iron mines, we used SBAS technique to process multi-orbit Sentinel-1 SAR data and proposed a solution method based on terrain features for radar line of sight (LOS) deformation to slope deformation, obtaining the slope deformation results of the northwest slope of the mining pit. At the same time, combining precipitation data and geological conditions, analyze the deformation conditions to explore the influence of rock structure, lithology, and precipitation on slope stability.

The third study site, Changbaishan volcano complex is affected by landslides, earthquakes, degassing, and ground deformation. Deformations occurred during the 2002-2006 unrest episode and in 2020-2022. Analysis on the multi-hazards of Changbaishan is very important because a population of ~135000 in China and 31000 in North Korea lives within 50 km far from the volcano. Using 33 Envisat ASAR images acquired during 2004-2010 along the descending orbit, the accurate surface deformation parameters of Changbaishan Tianchi volcano has been extracted through a modified multi-temporal InSAR approach which involves point selection based on the Normalized Difference Vegetation Index (NDVI), to minimize the volume decorrelation problem. Then, based on three-dimensional geometric relationship between the volcanic surface deformation field and the radar LOS deformation, Mogi point source modeling has been calculated, revealing the inflation-deflation-stabilization process of the magma chamber during the end of the 2002-2005 unrest episode. Furthermore, we analyze the deformation of Changbaishan volcano during 2018–2022 processing by means of the SBAS technique a dataset consisting of 23 ALOS-2 images (L-Band, StripMap acquisition mode), acquired along the ascending orbit and revealing a low-level unrest occurred during 2020.12-2021.6. We also processed Sentinel-1 data but due to the large loss of coherence related to the used C-Band not reliable results were obtained. So, subsequently only the ALOS-2 outcomes are used as input for the modelling of the source. Modeling results suggest that three active sources are responsible for the observed ground velocities: a deep tabular deflating source, a shallower inflating NW-SE elongated spheroid source, and a NW-SE striking dip-slip fault. The retrieved depth and geometry of the inferred sources are consistent with independent petrological and geophysical data.

Acknowledgments

The Sentinel-1 data are free of charge distributed by the European Space Agency. The COSMO-SkyMed data are provided by ASI through the ASI-ESA Dragon5 Project ID. 58029. The ALOS-2 data are provided by JAXA in the framework of the Announcement of Opportunities nr. PER2A2N173.

The Dragon-5 project SARchaeology marks an approach in the interdisciplinary fields of remote sensing, archaeology, and cultural heritage preservation. By leveraging the advanced capabilities of satellite Synthetic Aperture Radar (SAR) data, this project aims to develop methodologies for archaeological prospections and the protection of heritage sites. These methodologies are particularly tailored to facilitate continuous surface motion stability analysis and to enact precise change-detection mechanisms at sites of cultural heritage significance.

Throughout the course of the Dragon-5 initiative, an array of study sites, specifically in China, Russia, Italy, Norway, and Turkey, has been the focus of research and experimentation. However, the imposed sanctions on Russia precipitated a halt in collaborative efforts in the Russian test area, compelling the University of Sydney’s team members to redirect their focus towards the other sites.

A series of experiments conducted in Wuhan, China, have proven instrumental in showcasing the capability of SAR data to detect looting activities, a prevalent threat to archaeological and cultural heritage sites. The field experiment conducted in Wuhan allows for an experimental estimation of detectable looting hole sizes using very-high resolution SAR data.

Furthermore, the project has embraced a multi-sensor/multi-angle analytical approach, particularly for the detection of post-earthquake damage, an approach that was put to test following the devastating earthquake that struck Turkey and Syria on February 6, 2023. This tragic event underscored the paramount importance of the methodologies developed under the Dragon-5 umbrella, especially in terms of identifying damages to cultural heritage sites that are often elusive in SAR data without pre-disaster imagery for comparison.

In addition to the work conducted in China, multi-sensor site analyses in and around the historical expanse of Rome have revealed the advantages of employing multi-sensor approaches for the monitoring and preservation of cultural heritage sites. These methodologies have demonstrated significant potential in providing a comprehensive understanding of the threats faced by these sites and devising effective strategies for their protection.

The Dragon-5 project SARchaeology, illustrates the potential of remote sensing in making significant contributions to the preservation and protection of cultural heritage sites. As the project evolves, it continues to pave new pathways for the integration of technology and heritage conservation, promising a future where the treasures of our past are safeguarded for generations to come.