The Grange Orgiera landslide is a wide phenomenon of the Western Alps occurred in July 2009, located in Sampeyre municipality (CN, Piedmont), on the left side of the Varaita Valley. This is a complex landslide, in particular, classify as a rotational slide evolved in a flow like landslide. Its activation was related to the extraordinary abundant snowfall of 2008-2009 winter, identified as an anomalous event of the last forty-year of a climatological point of view [on-line report Arpa Piemonte, 2009], and the subsequent snowmelt. From a geomorphological point of view, this event represent a reactivation of a rotational landslide extended from 2150 m asl to 1720 m asl, close to the Grange Orgiera village. This landslide is included in a more extensive gravitative event, extended from Pian delle Serre (about 2270 m asl) to Villar municipality (about 1100 m asl). Moreover, at the slope scale, these landslides were included in a Deep Seated Gravitational Slope Deformation (DsGSD) of about 20 km2, between Villar and Casteldelfino hamlets. Starting from July 2009 the Grange Orgiera event was monitored with a topographic monitoring network, located in correspondence of the left frontal lobe of the landslide. The landslide was monitored for two distinct period: from August 2009 to October 2009, and from July 2010 to September 2010.

The SAR ground deformation time series relevant to Sampeyre frame include deformation data obtained from ASAR-Envisat satellite acquisitions (images available in the framework of Category-1A project, part of the ESA Geohazard Supersites initiative), and elaborated by the ESA’s G-POD service with the SBAS technique. In particular, the analysis provided 65535 measure points, for the observed period from April 2005 to October 2010, relative to the entire frame. The archive provide for each SBAS targets: - ID: Gr1; Gr2; Gr n - East and North UTM WGS84 coordinates (m); - Temporal interferometric coherence [CohT]; - Deformation velocity (cm/year) [Vel]; - Azimuth and Range coordinates [Az/Rg]; - Latitude and Longitude coordinates (deg) [Lat/Lon]; - Topography (m) [RT]; - Deformation Data (cm), related to the date of the exploited SAR images. The date of the exploited images are expressed as: [year+((month-1)*30+day)/365]. The SBAS results, relevant to the entire frame (normally around 100x100 km), have an accuracy of 1 mm/yr for mean velocity measurements, and 5 mm for the deformation measurements [Casu et al., 2006]. The deformation time series present a monthly temporal sampling, and provide long time series of deformation, allowing to follow the evolution of surface displacement over time.

The Montaldo di Cosola landslide is a complex landslide reactivated in the flood event occurred in autumn 1993, and located in Cabella Ligure municipality, in the mountain area of the Appennines (Alessandria, Piemonte, Northern Italy). This landslide was monitored with an inclinometer monitoring network installed in the Montaldo di Cosola Landslide made up two inclinometers and an automated inclinometer system (AIS) and two piezometers from 2000 to 2001, and three inclinometers, an automated inclinometer system and six piezometers from 2002 to 2004.

Relatively to the Grange Orgiera test site, a space-born analysis using the DInSAR technique, was done using the ESA’s Grid Processing On-Demand (G-POD) service, for a specific area of interest (AOI). The ASAR-Envisat dataset, available through the Virtual Archive 4 of ESA (by the Category-1A project, part of the ESA Geohazard Supersites initiative), was processes by using the G-POD service. The SAR dataset, made of 21 images acquired in ascending orbit (track 301) between April 2005 and October 2010, has been analyzed with the SBAS-DInSAR technique. The ASAR-Envisat satellite acquires images characterized by: - Band acquisition: C Band - Wavelength (cm): 5.6 - Incident angle (°): 23° - Azimuth/ground range resolution (m): ≈ 4/20 - Revisit time (days): 35 - Life status: 2002 – 2010 - Space agency: ESA Regarding the G-POD threshold setting of the SBAS processing, the following parameters were used: - Max Perpendicular Baseline (m): 400 - Max Temporal Baseline (days): 1500 - Ground Pixel Dimension (m): 80 - Coherence Threshold: 0.7 - Area of Interest (AOI): selected AOI close to the test site - REF point: Lat. 44.5838 – Lon. 7.1434 The achieved SBAS measurements are provided in geocoded coordinates (Lat/Lon and UTM WGS84), and are reported in an ASCII file. The SBAS results, relevant to the entire frame (normally around 100x100 km) have an accuracy of 1 mm/yr concerning the mean velocity measurements, and 5 mm for the deformation measurements [Casu et al., 2006].

The SAR ground deformation time series relevant to Grange Orgiera test site include deformation data obtained from ASAR-Envisat satellite acquisitions (images available in the framework of Category-1A project, part of the ESA Geohazard Supersites initiative), and elaborated by the ESA’s G-POD service with the SBAS technique. In particular provided 41555 measure points, for the observed period from April 2005 to October 2010, relative to the area of interest. The archive provide for each SBAS targets: - East and North UTM WGS84 coordinates (m); - Temporal interferometric coherence [CohT]; - Deformation velocity (cm/year) [Vel]; - Azimuth and Range coordinates [Az/Rg]; - Latitude and Longitude coordinates (deg) [Lat/Lon]; - Topography (m) [RT]; - Deformation Data (cm), related to the date of the exploited SAR images. The date of the exploited images are expressed as: [year+((month-1)*30+day)/365]. The SAR results, relevant to the entire frame (normally around 100x100 km), have an accuracy of 1 mm/yr concerning the mean velocity measurements, and 5 mm for the deformation measurements [Casu et al., 2006]. The deformation time series present a monthly temporal sampling, and provide long time series of deformation, allowing to follow the evolution of surface displacements over time.

Relatively to the Grange Orgiera test site, a space-born analysis, using the DInSAR technique, was done using the ESA’s Grid Processing On-Demand (G-POD) service, for the entire frame considered. The ASAR-Envisat dataset, available through the Virtual Archive 4 of ESA (by the Category-1A project, part of the ESA Geohazard Supersites initiative), was processed by using the G-POD service. The SAR dataset, made of 21 images acquired in ascending orbit (track 301) between April 2005 and October 2010, has been analyzed with the SBAS-DInSAR technique. The ASAR-Envisat satellite acquires images characterized by: - Band acquisition: C Band - Wavelength (cm): 5.6 - Incident angle (°): 23° - Azimuth/ground range resolution (m): ≈ 4/20 - Revisit time (days): 35 - Life status: 2002 – 2010 - Space agency: ESA Regarding the G-POD threshold setting of the SBAS processing, the following parameters were used: - Max Perpendicular Baseline (m): 400 - Max Temporal Baseline (days): 1500 - Ground Pixel Dimension (m): 80 - Coherence Threshold: 0.7 - Area of Interest (AOI): entire frame - REF point: Lat. 44.5838 – Lon. 7.1434 The achieved SBAS measurements provided in geocoded coordinates (Lat/Lon and UTM WGS84), and are reported in an ASCII file. The SBAS results, relevant to the entire frame (normally around 100x100 km), have an accuracy of 1 mm/yr concerning the mean velocity measurements, and 5 mm for the deformation measurements [Casu et al., 2006].

At the Grange Orgiera landslide a topographic monitoring network has been installed on August 2009. The topographic network has located upstream Grange Orgiera hamlet, in correspondence to the left frontal lobe of the landslide. The network consists of a robotic total station, associated to a solar panel and a backup battery that guarantees its operation, and a GSM modem that allows a download of the data by remote connection; eight prisms, seven of which inside the landslide and one close to the landslide foot, and two reference points outside the landslide. This network allowed the monitoring of the left frontal lobe of the landslide, which threatened the Puy village. The topographic network was installed on July 2009 and recorded during the spring-autumn months, in particular from August 2009 since October 2009. In 2010 have been installed five new prisms within the landslide body, near the left frontal lobe of the landslide, and the monitoring network recorded from July 2010 to September 2010. The monitoring network allowed several automatic displacement measurements of the prisms inside and outside the landslide, using a robotic total station Leica TCA 1800. This high-performance instrument for the ground displacement surveying, allow to measure the angle (Hz and V) and distance measurement. Data collected by this total station permit to improve knowledge on surface ground deformation, and the geomorphological evolution of the landslide. In particular, the TCA 1800 total station used is characterized by: - Angle-measurement accuracy: Standard deviation (ISO 17123-2) of 1” (0.3 mgon); - Distance measurement (IR): Standard deviation (ISO 17123-4) 1mm + 2 ppm; Range 2.500 m, under average atmospheric conditions, i.e. visibility 15 km. - Automatic target recognition (ATR), under good atmospheric conditions: Accuracy at below 200 m of 1 mm; Accuracy at 500 m of 2 mm – 3 mm. For more information: http://www.leica-geosystems.com/downloads123/zz/tps/tps2000/brochures/tps2000_brochure_it.pdf

The Grange Orgiera in situ ground deformation time series include deformation data from the topographic monitoring network, installed on the Grange Orgiera landslide. In particular, provide the differential displacement (in cm), of planimetric and altimetric displacement, for each prism of the network. The monitoring network includes eight prism inside (1, 2, 3, 4, 5, 7, 8, 20) the landslide and five within (6, 16, 17, 18, 19), located in correspondence of the left frontal lobe of the Grange Orgiera landslide. The archive provide two distinct time period: - August 2009 – October 2009, for the prisms from 1 to 8; - July 2010 – September 2010, for all the prisms. The time series present a very high temporal sampling (hourly), and provide the differential displacement for the planimetric (Δxy) and altimetric (Δz) displacement (in cm). All the spikes interpreted as noise were been delete to the time series.