Satellite-based monitoring of an open-pit mining site using Sentinel-1 advanced radar interferometry: A case study of the December 21, 2020, landslide in Toledo City, Philippines

Understanding the causal factors and mechanisms behind catastrophic landslides and debris flows is crucial for accurate forecasting and disaster risk reduction. Synthetic aperture radar (SAR) data and interferometric SAR (InSAR) technologies provide valuable information for early warning systems’ landslide and debris flow detection and monitoring strategies. This paper applied the Sentinel-1 Persistent Scatterer InSAR (PSInSAR) technique to detect and monitor precursory slope movements over the open-pit mining site in Toledo City, Cebu Island, in the Philippines. The results show that the slope showed instabilities between December 30, 2019, to December 12, 2020, before the actual failure on December 21, 2020. The landslide initiation zone moved with velocities exceeding –10 mm/yr and reaching –90 mm/yr. The topography and morphology of the mining site contributed to the cut slope instabilities. The mining operations and hydrometeorological conditions during the analysis period aggravated the situation, leading to the cut slope failure. Overall, with favorable slope geometry, surface characteristics, and SAR data availability, the Sentinel-1 PSInSAR technique can serve as a landslide early warning system tool and aid decision-making in an actively operating open-pit mine and other landscapes

Penerapan Metode Permanent Scatterers Interferometry Synthetic Aperture Radar (PS-InSAR) untuk Analisis Deformasi Gunungapi (Studi Kasus : Gunungapi Sinabung)

Di Indonesia terdapat 129 gunungapi yang masih aktif, salah satunya adalah Gunungapi Sinabung. Sepanjang tahun 2017 tercatat Gunungapi Sinabung mengalami erupsi-erupsi kecil akibat aktivitas magma. Pada gunungapi yang sedang aktif akan terjadi perubahan bentuk permukaan tanah yang disebut sebagai deformasi permukaan. Untuk memantau deformasi dapat digunakan berbagai macam metode, antara lain metode geodetik dengan menggunakan pengamatan GPS dan pengolahan data SAR dengan  teknik PS-InSAR. Penelitian ini dilakukan untuk mengetahui deformasi yang terjadi pada gunungapi menggunakan metode PS-InSAR dengan  validasi menggunakan data GPS. Data SAR yang digunakan, terdiri dari 27 citra Sentinel 1A tipe SLC dengan tanggal akuisisi 2 Januari hingga 28 Desember 2017. Hasil dari PS-InSAR menunjukkan line of sight (LOS) velocity rate yang terjadi berkisar pada -40,400 mm/tahun sampai dengan 30,800 mm/tahun dengan simpangan baku berkisar pada 1,400 mm/tahun sampai dengan 31,800 mm/tahun

Employment of Free Packages for MT-InSAR Approaches to Verify the Subsidence Event over Maceió City, Brazil

Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique employs a Multi-Temporal InSAR (MT-InSAR) approach to accurately measure subsidence. This technique, a type of Differential Interferometry (DInSAR), mitigates errors that traditional DInSAR techniques cannot, including temporal and geometric decorrelation, and phase unwrapping errors. In order to verify the subsidence process in the Pinheiro neighborhood of Maceio - Brazil following a 2018 earthquake, we tested free processing packages such as SNAP-StaMPS integration. Our investigation was conducted in two stages: first, using a stack of Sentinel-1A SLCSAR (Single Look Complex-SAR) images acquired before and after the earthquake, and second, using more recent images to determine if the subsidence process is ongoing. Results from the first stage identified the area affected by subsidence and the second stage confirmed the continued presence of subsidence events. From 2017 to 2018, the subsidence process exhibited the highest displacement amplitude of -32.3 mm/year, whereas, between 2021 and 2022, the amplitude decreased to -24.09 mm/year, indicating a deceleration in the subsidence process

Estimating Landfill Landslide Probability Using SAR Satellite Products: A Novel Approach

[EN] This article presents a methodology for evaluating the susceptibility of landfill areas to develop landslides by analyzing Synthetic Aperture Radar (SAR) satellite products. The deformation velocity of the landfills is computed through the Persistent Scatterer Method on SAR imagery. These data, combined with a deformation model based on the shallow water equations (SWE), form the foundation for a Monte Carlo experiment that extrapolates the current state of the landfill into the future. The results of this simulation are then employed to determine the probability of a landslide occurrence. In order to validate the methodology effectiveness, a case study is conducted on a landfill in Zaldibar, Spain, revealing its effectiveness in estimating the probability of landfill landslides. This innovative approach emerges as an asset in large landfill management, acting as a proactive tool for identifying high-risk sites and preventing potential landslides, ultimately safeguarding human life and the environment. By providing insights into landslide probabilities, this study enhances decision-making processes and facilitates the development of intervention strategies in the domain of landfill risk assessment and management.SIEuropean Space Agenc

Efecto de la subsidencia en el nivel medio del mar de la ciudad de Cartagena de Indias: una aproximación empleando interferometría de radar de apertura sintética

El nivel medio del mar está aumentado como consecuencia del cambio climático. No obstante, la manera cómo afecta las zonas costeras, también depende de las variaciones verticales del terreno. Una herramienta que surge en el siglo XXI es el InSAR, que funciona como método para medir el desplazamiento vertical de la corteza que puede presentar una zona costera. Al aplicar esta técnica, se puede tener un valor de referencia de la variación vertical de un terreno, que puede afectar el reporte del aumento relativo del nivel del mar que presenta una comunidad costera. Actualmente, existen múltiples imágenes de satélite y software de procesamiento que sirven para la generación de rangos de subsidencia que afecta a una ciudad. En este trabajo, se utilizan las imágenes de radar del Sentinel-1, junto con los programas SNAP, SNAP2StaMPS y StaMPS para crear un mapa de desplazamiento vertical de la ciudad de Cartagena de Indias, con el fin de definir valores de subsidencia en la ciudad en el periodo 2015-2021. Los resultados indican que la tasa de variación vertical del terreno se encuentra entre el rango de 4 y -6 mm/año, dependiendo del punto de la ciudad que se observe. Se recomienda la generación de nuevos mapas a medida que aumente la información disponible y que esta sea de mejor resolución.PregradoGeólog

Multitemporal Sentinel-1 and Sentinel-2 Images for Characterization and Discrimination of Young Forest Stands Under Regeneration in Norway

There is a need for mapping of forest areas with young stands under regeneration in Norway, as a basis for conducting tending, or precommercial thinning (PCT), whenever necessary. The main objective of this article is to show the potential of multitemporal Sentinel-1 (S-1) and Sentinel-2 (S-2) data for characterization and detection of forest stands under regeneration. We identify the most powerful radar and optical features for discrimination of forest stands under regeneration versus other forest stands. A number of optical and radar features derived from multitemporal S-1 and S-2 data were used for the class separability and cross-correlation analysis. The analysis was performed on forest resource maps consisting of the forest development classes and age in two study sites from south-eastern Norway. Important features were used to train the classical random forest (RF) classification algorithm. A comparative study of performance of the algorithm was used in three cases: I) using only S-1 features, II) using only S-2 optical bands, and III) using combination of S-1 and S-2 features. RF classification results pointed to increased class discrimination when using S-1 and S-2 data in relation to S-1 or S-2 data only. The study shows that forest stands under regeneration in the height interval for PCT can be detected with a detection rate of 91% and F-1 score of 73.2% in case III as most accurate, while tree density and broadleaf fraction could be estimated with coefficient of determination (R 2 ) of about 0.70 and 0.80, respectively

ESA SNAP – Stamps integrated processing for sentinel-1 persistent scatterer interferometry

International audienc

Elevation change of Bhasan Char measured by persistent scatterer interferometry using Sentinel-1 data in a humanitarian context

This study investigates the elevation changes for the island of Bhasan Char, located in the Bay of Bengal, which was selected for the relocation of around 100,000 refugees of the Rohingya minority which were forced to leave their homes in Myanmar. Eighty-nine Sentinel-1 products were analysed using persistent scatterer interferometry (PSI) beginning August 2016 through September 2019, divided into three periods of one year to reduce the impact of temporal decorrelation. The findings indicate that the island is a recent landform which underlies naturally induced surface changes with velocities of up to ±20 mm per year. Additional displacement is probably caused by heavy construction loads since early 2018, although we found no statistical evidence for this. The main built-up area shows stable behaviour during the analysed period, but there are significant changes along the coasts and artificial embankments of the island, and within one separate settlement in the north. The moist surface conditions and strong monsoonal rains complicated the proper retrieval of stable trends, but the sum of findings supports the assumption that the island underlies strong morphologic dynamics which put the people to be relocated at additional risk. Its suitability for construction has to be investigated in further studies