Sara Del Conte

Exploitation of Amplitude and Phase of Satellite SAR Images for Landslide Mapping: The Case of Montescaglioso (South Italy)

Pre- event and event landslide deformations have been detected and measured for the landslide that occurred on 3 December 2013 on the south-western slope of the Montescaglioso village (Basilicata Region, southern Italy). In this paper, ground displacements have been mapped through an integrated analysis based on a series of high resolution SAR (Synthetic Aperture Radar) images acquired by the Italian constellation of satellites COSMO-SkyMed. Analysis has been performed by exploiting both phase (through multi-image SAR interferometry) and amplitude information (through speckle tracking techniques) of the satellite images. SAR Interferometry, applied to images taken before the event, revealed a general pre-event movement, in the order of a few mm/yr, in the south-western slope of the Montescaglioso village. Highest pre-event velocities, ranging between 8 and 12 mm/yr, have been recorded in the sector of the slope where the first movement of the landslide took place. Speckle tracking, applied to images acquired before and after the event, allowed the retrieval of the 3D deformation field produced by the landslide. It also showed that ground displacements produced by the landslide have a dominant SSW component, with values exceeding 10 m for large sectors of the landslide area, with local peaks of 20 m in its central and deposit areas. Two minor landslides with a dominant SSE direction, which were detected in the upper parts of the slope, likely also occurred as secondary phenomena as consequence of the SSW movement of the main Montescaglioso landslide.

Continuous, semi-automatic monitoring of ground deformation using Sentinel-1 satellites

We present the continuous monitoring of ground deformation at regional scale using ESA (European Space Agency) Sentinel-1constellation of satellites. We discuss this operational monitoring service through the case study of the Tuscany Region (Central Italy), selected due to its peculiar geological setting prone to ground instability phenomena. We set up a systematic processing chain of Sentinel-1 acquisitions to create continuously updated ground deformation data to mark the transition from static satellite analysis, based on the analysis of archive images, to dynamic monitoring of ground displacement. Displacement time series, systematically updated with the most recent available Sentinel-1 acquisition, are analysed to identify anomalous points (i.e., points where a change in the dynamic of motion is occurring). The presence of a cluster of persistent anomalies affecting elements at risk determines a significant level of risk, with the necessity of further analysis. Here, we show that the Sentinel-1 constellation can be used for continuous and systematic tracking of ground deformation phenomena at the regional scale. Our results demonstrate how satellite data, acquired with short revisiting times and promptly processed, can contribute to the detection of changes in ground deformation patterns and can act as a key information layer for risk mitigation.

Cultural Heritage, Landslide Risk and Remote Sensing in Italy

Italy is the country that owns most of the world cultural heritage and is affected by a very large number of landslides widespread throughout its territory. Aim of the work is to define a methodology, developed on GIS platform, in order to assess cultural heritage exposed to very slow and extremely slow mass movements using: SAR data, the Italian Cultural Heritage database and the Italian Landslide Inventory. The methodology has been developed at provincial level and tested on Macerata province. A single building approach has been also performed on six cultural heritage. The proposed methodology could be applied to all cultural heritage sites in Italy to identify priorities and plan field surveys, detailed studies and monitoring systems.

Application of SqueeSAR™ to the Characterization of Deep Seated Gravitational Slope Deformations: The Berceto Case Study (Parma, Italy)

SqueeSAR™ SAR interferometry is today one of the most advanced technologies for surface deformation monitoring capable of overcoming most of the limitations of conventional differential radar interferometry. It exploits long temporal series of satellite radar data, acquired over the same area of interest at different times, to identify “natural radar targets” where very precise displacement information can be retrieved.

Mapping Rapid-Moving Landslide with Satellite SAR Images: The Case of Montescaglioso (South Italy)

Pre-event and event landslide deformations have been detected and measured for the landslide that occurred on December 3rd, 2013 on the south-western slope of the Montescaglioso village (Basilicata Region, Southern Italy). The event, triggered by 56 h of continuous rainfalls, produced a ground displacement of several meters and created significant damages to buildings and local infrastructures. Ground displacements have been mapped through an integrated analysis based on a series of high resolution SAR (Synthetic Aperture Radar) images acquired by the Italian constellation of satellites COSMO-SkyMed. The purpose of this mapping activity was twofold: (i) detect and record any pre-event deformation in and around the village of Montescaglioso, through the use of multi-image SAR interferometry, suitable for mapping slow deformation phenomena and (ii) map and measure any surface changes produced by the 3rd December landslide, using amplitude-based method, suitable for mapping much faster displacements. SAR Interferometry, applied to images taken before the event, revealed a general pre-event movement, in the order of a few mm/year, in the south-western slope of the Montescaglioso village, with highest velocities in the sector of the slope where the first movement of the landslide took place. Amplitude analysis allowed the retrieval of the three components of the landslide deformation field, with values exceeding 10 m for large sectors of the landslide area and local peaks of 20 m in its central and deposit areas. The synergistic exploitation of phase and amplitude of SAR images turned out to be a powerful tool for landslide investigation, allowing the detection of slow, precursory deformation patterns as well the retrieval of full 3D surface displacement fields caused by large, rapid-moving landslides.

Advanced Satellite InSAR Technology For Fault Analysis And Tectonic Setting Assessment. Application To Reservoir Management And Monitoring.

Hydrocarbon reservoir operation, i.e. fluid extraction and injection, are responsible for volumetric changes of reservoir itself resulting in surface deformation phenomena (subsidence or uplift). This processes are controlled by the tectonic framework which is responsible for reservoir compartmentalization and/or fault reactivation. Monitoring surface deformations can provide valuable constraints for modeling the dynamic behavior of a reservoir and help achieve more effective reservoir exploitation with obvious economic benefits. Advanced satellite interferometry represents one of the most valuable and cost-effective techniques, capable of providing high precision and high areal density displacement measurements over long periods of time.