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This work is focused on deformation activity mapping and monitoring using Sentinel-1 (S-1) data and the DInSAR (Differential Interferometric Synthetic Aperture Radar) technique. The main goal is to present a procedure to periodically update and assess the geohazard activity (volcanic activity, landslides and ground-subsidence) of a given area by exploiting the wide area coverage and the high coherence and temporal sampling (revisit time up to six days) provided by the S-1 satellites. The main products of the procedure are two updatable maps: the deformation activity map and the active deformation areas map. These maps present two different levels of information aimed at different levels of geohazard risk management, from a very simplified level of information to the classical deformation map based on SAR interferometry. The methodology has been successfully applied to La Gomera, Tenerife and Gran Canaria Islands (Canary Island archipelago). The main obtained results are discussed. [ABSTRACT FROM AUTHOR]

Satellite interferometric data are widely exploited for ground motion monitoring thanks to their wide area coverage, cost efficiency and non-invasiveness. The launch of the Sentinel-1 constellation opened new horizons for interferometric applications, allowing the scientists to rethink the way in which these data are delivered, passing from a static view of the territory to a continuous streaming of ground motion measurements from space. Tuscany Region is the first worldwide example of a regional scale monitoring system based on satellite interferometric data. The processing chain here exploited combines a multi-interferometric approach with a time-series data mining algorithm aimed at recognizing benchmarks with significant trend variations. The system is capable of detecting the temporal changes of a wide variety of phenomena such as slow-moving landslides and subsidence, producing a high amount of data to be interpreted in a short time. Bulletins and reports are derived to the hydrogeological risk management actors at regional scale. The final output of the project is a list of potentially hazardous and accelerating phenomena that are verified on site by field campaign by completing a sheet survey in order to qualitatively estimate the risk and to suggest short-term actions to be taken by local entities. Two case studies, one related to landslides and one to subsidence, are proposed to highlight the potential of the monitoring system to early detect anomalous ground changes. Both examples represent a successful implementation of satellite interferometric data as monitoring and risk management tools, raising the awareness of local and regional authorities to geohazards. [ABSTRACT FROM AUTHOR]

Landslides are considered to be one of the main natural geohazards causing relevant economic damages and social effects worldwide. Italy is one of the countries worldwide most affected by landslides; in the Region of Tuscany alone, more than 100,000 phenomena are known and mapped. The possibility to recognize, investigate, and monitor these phenomena play a key role to avoid further occurrences and consequences. The number of applications of Advanced Differential Interferometric Synthetic Aperture Radar (A-DInSAR) analysis for landslides monitoring and mapping greatly increased in the last decades thanks to the technological advances and the development of advanced processing algorithms. In this work, landslide-induced damage on structures recognized and classified by field survey and velocity of displacement re-projected along the steepest slope were combined in order to extract fragility curves for the hamlets of Patigno and Coloretta, in the Zeri municipality (Tuscany, northern Italy). Images using ERS1/2, ENVISAT, COSMO-SkyMed (CSK) and Sentinel-1 SAR (Synthetic Aperture Radar) were employed to investigate an approximate 25 years of deformation affecting both hamlets. Three field surveys were conducted for recognizing, identifying, and classifying the landslide-induced damage on structures and infrastructures. At the end, the damage probability maps were designed by means of the use of the fragility curves between Sentinel-1 velocities and recorded levels of damage. The results were conceived to be useful for the local authorities and civil protection authorities to improve the land managing and, more generally, for planning mitigation strategies. [ABSTRACT FROM AUTHOR]

The results of the continuous monitoring of ground deformation throughout the Tuscany region using radar images acquired by the Sentinel-1 satellite constellation of the European Space Agency (ESA) are presented here. This new monitoring approach, based on systematic imagery processing and analysis of deformation time series, is discussed at regional (for the entire Tuscany) and at local scale in the context of a case study of the Carpineta landslide, which is a large, active earth slide in the Northern Apennines (Pistoia province). The landslide registered an acceleration during the winter and spring of 2018 as a direct consequence of rainfall and snow melt. The increase in the deformation rate of the landslide, which led to the damage of several buildings, was promptly detected and monitored due to the enhanced temporal repetitiveness offered by the Sentinel-1 constellation. The results demonstrate that advances in satellite sensors, increases in computing capacity and the refinement of processing approaches and data screening tools can contribute to the development of new paradigms in satellite-based monitoring systems. Sentinel-1 data, which are systematically acquired with short revisiting times and then promptly processed, can now be used as a tool for the systematic tracking of ground deformation at the regional scale and for the continuous monitoring of slow and very slow landslides. [ABSTRACT FROM AUTHOR]

Persistent Scatterer Interferometry (PSI) is a consolidated tool for detecting and monitoring ground surface displacements. The availability of satellite data with free access policy and high monitoring capabilities (in terms of resolution and acquisition frequency) is increasing. Moreover, the first continental displacement map of Europe will be freely available in quarter one 2022 by the latest Copernicus Service, the European Ground Motion Service (EGMS). The EGMS will provide ground displacement maps, updated every year, delivering valuable information to a wide range of users, such as public or governmental institutions, industry, academia, and citizens. This vast amount of information needs semi-automatic tools and methodologies to derive user-oriented products that can be easily used by land use and urban planning decision-makers, who are often unfamiliar with PSI. This work proposes a semi-automatic procedure to identify damage prone areas in urban environments from wide-area PSI displacement maps. The proposed method identifies the most significant Active Deformation Areas (ADAs) to calculate three products based on the displacement intensity gradient: the Gradient Intensity Map, the Gradient Vectors and Time Series, and the Potential Damage Map. These products allow identifying buildings and urban structures exposed to potential damage, which could be followed by a more detailed building-based vulnerability and risk assessment. The methodology has been applied to an area of the province of Granada (Andalucía, Spain) but it can be applied to any other urban environment where PSI displacement maps are available. To demonstrate the advantages and limitations of the proposed method, results are discussed in five coastal resorts (Cerro Gordo, Punta de la Mona, Marina del Este, Alfa Mar, and Monte de los Almendros), strongly affected by slope movements. The methodology allowed to derive 175 ADAs from about 200,000 measurement points. About 15% of the resulting area has been found to correspond to high or very high gradient intensity class, and 192 out of 633 buildings have been identified to be prone to moderate or high potential damage. A damage prediction test has been realized through Receiver Operating Characteristic (ROC) analysis, based on a damage inventory map derived from field surveys. The results demonstrate the effectiveness of the methodology to localize damaged or potentially damaged buildings, substantially reducing the time of analysis. • A step towards the automatic exploitation of satellite interferometric (InSAR) data. • Automatic exploitation of PSI to support a multi-scale geohazard risk management. • A methodology for the automatic exploitation of EGMS continental displacement maps. • Potential Damage Maps based on spatial gradients of velocity and angular distortion. • Regional scale detection of coastal landsides causing damages in Granada Region. [ABSTRACT FROM AUTHOR]