0000000000547918
AUTHOR
Nicola Casagli
G-CLASS: geosynchronous radar for water cycle science – orbit selection and system design
The mission geosynchronous – continental land atmosphere sensing system (G-CLASS) is designed to study thediurnal water cycle, using geosynchronous radar. Although the water cycle is vital to human society, processes on timescalesless than a day are very poorly observed from space. G-CLASS, using C-band geosynchronous radar, could transform this. Itsscience objectives address intense storms and high resolution weather prediction, and significant diurnal processes such assnow melt and soil moisture change, with societal impacts including agriculture, water resource management, flooding, andlandslides. Secondary objectives relate to ground motion observations for earthquake, volcano, and subs…
Advanced radar-interpretation of InSAR time series for mapping and characterization of geological processes
Abstract. We present a new post-processing methodology for the analysis of InSAR (Synthetic Aperture Radar Interferometry) multi-temporal measures, based on the temporal under-sampling of displacement time series, the identification of potential changes occurring during the monitoring period and, eventually, the classification of different deformation behaviours. The potentials of this approach for the analysis of geological processes were tested on the case study of Naro (Italy), specifically selected due to its geological setting and related ground instability of unknown causes that occurred in February 2005. The time series analysis of past (ERS1/2 descending data; 1992–2000) and current…
Insar time-series analysis for management and mitigation of geological risk in urban area
This work shows the capabilities of InSAR time series analyses to support civil protection activities in the framework of geological risk management and mitigation. We discuss the outcomes from an integrated analysis of conventional in situ investigations and observations with advanced InSAR analyses carried out for the test sites of Agrigento and Naro (Italy), affected by ground instability respectively due to landsliding and tectonic forces. The study of past ground deformations provided valuable insights into the spatial and temporal patterns and behaviors of these phenomena, helping local civil protection authorities to focus resources on the areas of maximum need and to identify the mo…
Landslide Impacts on Agrigento’s Cathedral Imaged with Radar Interferometry
ERS1/2 (1992–2000), ENVISAT (2002–2008) and RADARSAT1 (2003–2007) satellite data, processed with Persistent Scatterer Interferometry, are exploited to study the historic urban area of Agrigento, Italy, whose structural stability is threatened by retrogressive landslide processes. Up to 2–5mm/year of line-of-sight displacement are observed in 1992–2008 on the staircase and the left aisle of the Cathedral. Displacement acceleration to 13–15mm/year is measured in July 2006–May 2007, in the northern portion of the churchyard, in front of the left aisle. The areas moving at higher rates, located at the edge of the NW slope of Girgenti hill, correspond to those showing major structural damages. A…
Ground instability in the old town of Agrigento (Italy) depicted by on-site investigations and Persistent Scatterers data
We combine on-site investigations with the interpretation of satellite Persistent Scatterers (PS) to analyse ground instability in the historic town of Agrigento, Italy. Geological and geomorphologic surveys, together with geostructural and kinematic analyses, depict the deformational patterns of the northwestern sector of the town, previously documented by extensive literature available for the neighbouring Valley of the Temples. The geological and geomorphologic maps are reconstructed by combining bibliographic studies, field surveys and aerial stereo-interpretation. ERS-1/2 PS data reveal deformation velocities up to 18–20 mm yr<sup>−1</sup> in 1992–2000 over the Addolorata l…
Integrated geomorphological mapping in the north-western sector of Agrigento (Italy)
The geomorphological map is an essential tool to perform a proper urban planning in mountainous or hilly areas. In this paper a multidisciplinary approach to derive a 1:2000 geomorphological map is described. The proposed methodology consists of the integration between aerial photographs, acquired in 2003, and four datasets of Persistent Scatterer Interferometry (PSI) measures to update a pre-existing landslide inventory. The integrated data were used to achieve a validated geomorphological map by means of a geomorphological survey. The study area is located in southern Italy (Agrigento, Sicily). The city of Agrigento, included in the World Heritage List of UNESCO in 1997, is located on the…