The Need for a Standardized Methodology for Quantitative Assessment of Natural and Anthropogenic Land Subsidence: The Agosta (Italy) Gas Field Case

Abstract

In the last years, the advanced synthetic aperture radar (SAR) interferometry (InSAR) has proven its effectiveness in the assessment of ground gotion with millimetric accuracy. Its integrated use with traditional (in-situ) topographic height determination techniques, such as geometric leveling and Global Navigation Satellite System (GNSS), is consolidated in underground fluids extraction areas for detecting and monitoring land subsidence. Nevertheless, the lack of a specific standardized methodology does not allow for evaluating different results obtained from different types of analysis. Starting from the description of two independent estimations of land subsidence in the Agosta (Comacchio, Italy) area, where an environmental impact assessment procedure was carried out following a request for gas exploitation, this paper points out the need for a standardized methodology, focused on the in-situ calibration of InSAR data. This last purpose requires an adequately dense and homogeneous reference GNSS network. The in progress initiatives, at European and national level, aiming at providing a Copernicus Ground Motion service could offer the opportunity to structure a reliable and dedicated GNSS network, starting from the large amount of stations run by different institutions already existing in Italy.

Monitoring surface deformation of deep salt mining in Vauvert (France), combining InSAR and leveling data for multi-source inversion

“…Terrestrial (e.g., leveling, inclinometry) and satellite-based (e.g., GNSS, InSAR) geodetic measurements are complementary in terms of accuracy and spatial or temporal resolution, from slow ground displacement monitoring (e.g., Hastaoglu et al, 2017) to rapid surface changes (e.g., Peltier et al, 2017). Many attempts to combine these geodetic measurements have been described and published recently (e.g., Catalão et al, 2009;Burdack, 2013;Lu et al, 2015), to overcome the limitations and inadequacies of the different techniques in difficult contexts, when taken separately (e.g., Karila et al, 2013;Abidin et al, 2015;Fuhrmann et al, 2015;Comerci and Vittori, 2019). The combination of several geodetic measurement techniques aims to improve the knowledge of the ground motion by overcoming or at least mitigating each technique's shortcomings with the other.…”

Regression Analysis of Subsidence in the Como Basin (Northern Italy): New Insights on Natural and Anthropic Drivers from InSAR Data

“…Traditionally, land subsidence is monitored via in situ techniques, for example using GPS or geodetic leveling [9,10], which allow pointwise, precise, and reliable measurements of the ground subsidence rates [5]. These instruments are usually positioned on a few selected benchmark areas belonging to local or regional networks because of the cost of their installation and maintenance, thus resulting in a lack of measurement density over large areas [5].…”

Ground Deformation Monitoring at Continental Scale: The European Ground Motion Service

“…The services are based on Sentinel-1 imagery, using a 12-day image update (Raspini et al, 2018;Solari et al, 2019;. Other regions will follow in the near future, as planned in the Italian Space Economy Strategic Plan (Comerci and Vittori, 2019).…”