InSAR (space-borne Synthetic Aperture Radar Interferometry) data has revealed to be useful for su... more InSAR (space-borne Synthetic Aperture Radar Interferometry) data has revealed to be useful for surveying landslides and permafrost creeping features (e.g. rock glaciers) as it permits a time-lapse quantification of topography changes at mm to cm resolution over alpine areas where dense vegetation is no longer present. The capability of InSAR for detecting both the location of moving zones and the magnitude of their displacement rate has been successfully tested in various regions of the Swiss Alps. Research challenges are mainly focusing on the possibilities of using InSAR for monitoring tasks. The present contribution presents first basic principles, potentials and limitations of InSAR and its use in a mountain area. Then, it overviews some past, present and future InSAR projects dealing with the detection and the monitoring of moving zones in the Alpine periglacial belt.
This paper proposes a semi-automated method to update inventory of moving slopes. First a Map of ... more This paper proposes a semi-automated method to update inventory of moving slopes. First a Map of Terrain Activity (MTA) is created by partitioning an interferogram, using segmentation and classification processes, into 3 regions: stable areas, coherently moving parts and decorrelated areas (due to motion or not). Then, a Combined-Map of Terrain Activity (C-MTA) is computed describing the general behavior of the terrain at a specific time-lapse. Finally, C-MTA is used to determine the potential change in the activity rate of moving slopes. Tests are performed in a small area using large set of TSX DInSAR scenes from summers 2008 to 2012 in order to update past moving slope inventories produced from ERS DInSAR data.
TSX Insar Assessment for Slope Instabilities Monitoring in Alpine Periglacial Environment ( Western Swiss Alps , Switzerland )
The potential of Terrasar-X (TSX) InSAR for the acquisition of high resolution X-band interferogr... more The potential of Terrasar-X (TSX) InSAR for the acquisition of high resolution X-band interferograms with an 11 day time interval has been investigated for the monitoring of creeping landforms in the alpine periglacial belt. In order to give a reliable assessment of InSAR visibility, an index characterizing the velocity compression is calculated for 30 surveyed landforms like rockglaciers, landslides and debris covered glaciers. Results show that the monitoring of some very active rockglaciers (1-3.5m/y) may be possible when the latter are not hidden by layover or shadow. Moreover, compared to lower resolution data, TSX is well suitable to monitor active landforms. Even if field measurements are, in most cases, still needed to validate and confirm observations at local scale, TSX InSAR appears to be an efficient remote sensing method to monitor slope instabilities in this environment.
Kinematic observations of the mountain cryosphere using in-situ GNSS instruments 2011-2021
This dataset collates data of continuously acquired kinematic observations obtained through in-si... more This dataset collates data of continuously acquired kinematic observations obtained through in-situ Global Navigation Satellite Systems (GNSS) instruments that have been designed and implemented in a large-scale multi field-site monitoring campaign across the whole Swiss Alps. The landforms covered include rock glaciers, high-alpine steep bedrock bedrock as well as landslide sites, most of which are situated in permafrost areas. The dataset was acquired at 54 different stations situated at locations from 2304 to 4003 meter a.s.l and comprises 209'948 daily positions derived through double-differential GNSS post-processing. Apart from these, the dataset contains down-sampled and cleaned time series of weather station and inclinometer data as well as the full set of GNSS observables in RINEX format. Furthermore the dataset is accompanied by tools for processing and data management in order to facilitate reuse, open alternate usage opportunities and support the life-long living dat...
Landslide risk management in Switzerland Abstract Six percent of Switzerland is prone to slope in... more Landslide risk management in Switzerland Abstract Six percent of Switzerland is prone to slope instability. New federal regulations require regional authorities (cantons) to generate natural hazard maps and the zoning of mass movements in order to restrict development on hazard-prone land. The Codes of Practice for hazard maps use red, blue and yellow respectively, to indicate areas of prohibited construction, construction with safety requirements and construction without restriction. They need considerable efforts to ensure communication with local populations. The present state of landslide hazard mapping in the 26 cantons, the transcription of hazard maps to local management plans and the corresponding rules are presented.
Use of Persistent Scatterer InSAR within Terrafirma Landslide Services
Landslide Science and Practice, 2013
ABSTRACT Landslide Services of the pan-European project Terrafirma are presented. LandSlide Inven... more ABSTRACT Landslide Services of the pan-European project Terrafirma are presented. LandSlide Inventory (LSI) and LandSlide Monitoring (LSM) exploit satellite Persistent Scatterer InSAR (Synthetic Aperture Radar Interferometry) to monitor extremely to very slow moving landslides at both regional and local scale. Validated case studies of LSI in the Upper Tena Valley (Central Pyrenees, Spain) and LSM in Val Lumnez (Switzerland) are described. 14 TerraSAR-X descending images acquired in May–October 2008 are processed with the Stable Point Network (SPN) technique, and used to update the landslide inventory of the Upper Tena Valley, significantly improving the pre-existing landslide mapping. 68 ERS1/2 and ENVISAT ascending scenes, acquired in May 1992–October 2005 and processed with the Interferometric Point Target Analysis (IPTA) technique, are combined with topographic levelling measurements performed in 1887–1992, and exploited to monitor the Val Lumnez landslide and to improve the geomorphologic zonation.
Six percent of Switzerland is prone to slope instability. New federal regulations require regiona... more Six percent of Switzerland is prone to slope instability. New federal regulations require regional authorities (cantons) to generate natural hazard maps and the zoning of mass movements in order to restrict development on hazard-prone land. The Codes of Practice for hazard maps use red, blue and yellow respectively, to indicate areas of prohibited construction, construction with safety requirements and construction without restriction. They need considerable efforts to ensure communication with local populations. The present state of landslide hazard mapping in the 26 cantons, the transcription of hazard maps to local management plans and the corresponding rules are presented.
The potential of ERS InSAR for detecting slope motion in a periglacial mountain environment has b... more The potential of ERS InSAR for detecting slope motion in a periglacial mountain environment has been tested in the western part of the Swiss Alps. An inventory has been built from the analysis of the InSAR data. It contains a large number of areas that can be possibly attributed to various types of mass movement (glacier, debris-covered glacier, rock glacier, landslide, sagging, gelifl uction) occurring with various rates of activity above the tree line. The applied methodology is briefl y described and several typical examples of detected slope movement are illustrated.
Analysis of InSAR data permits the systematic detection of mass wasting phenomena in mountain are... more Analysis of InSAR data permits the systematic detection of mass wasting phenomena in mountain areas, particularly rock glaciers. ERS 1-day and 3-day InSAR scenes have been used successfully to evidence the occurrence of rapidly moving rock glaciers (> 2-3 m/year). The availability of InSAR data with short time lag – what is still no more the case since a decade ago – has proven to be an important tool for the assessment of natural hazards in mountain permafrost areas.
InSAR (space-borne Synthetic Aperture Radar Interferometry) data has revealed to be useful for su... more InSAR (space-borne Synthetic Aperture Radar Interferometry) data has revealed to be useful for surveying landslides and permafrost creeping features (e.g. rock glaciers) as it permits a time-lapse quantification of topography changes at mm to cm resolution over alpine areas where dense vegetation is no longer present. The capability of InSAR for detecting both the location of moving zones and the magnitude of their displacement rate has been successfully tested in various regions of the Swiss Alps. Research challenges are mainly focusing on the possibilities of using InSAR for monitoring tasks. The present contribution presents first basic principles, potentials and limitations of InSAR and its use in a mountain area. Then, it overviews some past, present and future InSAR projects dealing with the detection and the monitoring of moving zones in the Alpine periglacial belt.
As part of the ESA Terrafirma Project an in terferometric point target analysis (IPTA) was conduc... more As part of the ESA Terrafirma Project an in terferometric point target analysis (IPTA) was conducted to monitor the LUMNEZ landslide. The main interferometric result consists of the average line-of- sight deformation rates and the deformation histories for the selected points. The observed deformation rates reach values up to several centimeters per year. The interferometric result was delivered to the Swiss Federal Office for Environment and to the University of Florence where it was further interpreted. Combining IPTA results with the use of digital terrain data, aerial imagery and in-situ data a geomorphologic and geological interpretation of the Lumnez landslide was carried out. DTM data and aerial imagery allowed a geomorphologic zonation of the unstable slope taking into account derivates of the DTM as shaded relief, slope and aspect map. A field survey enabled the assessment of findings from the satellite monitoring, with the identification of damaged buildings and morphologi...
Quantifying a contemporary paraglacial rock slope response in the Aletsch region, Switzerland
ABSTRACT Numerous alpine valleys have been undergoing elevated rates of deglaciation since the en... more ABSTRACT Numerous alpine valleys have been undergoing elevated rates of deglaciation since the end of the Little Ice Age. Processes associated with the transition from glacial to non-glacial conditions influence the stability of surrounding rock slopes. Using a combination of remote sensing (radar interferometry and LiDAR), and field survey techniques we quantify rock slope movements with respect to glacier ice volume loss currently taking place at the terminus of the Great Aletsch Glacier in Switzerland. We discuss the influence of structural predisposition and triggering factors on the kinematic response of the rock slope.
ERS InSAR has been used for mapping and assessing slope movements in an alpine periglacial test r... more ERS InSAR has been used for mapping and assessing slope movements in an alpine periglacial test region. A large number of areas have thus been recognized as affected by mass wasting related to permafrost or not. Glaciers and most of the active geomorphic landforms display in fact typical ERS InSAR signals. A typology has been established. It can be seen as a useful tool to interpret ERS InSAR data in such a mountain environment.
1WSL Institute for Snow and Avalanche Research SLF, Switzerland 2WSL Institute for Snow and Avala... more 1WSL Institute for Snow and Avalanche Research SLF, Switzerland 2WSL Institute for Snow and Avalanche Research SLF, Switzerland 3ETH Zürich, Computer Engineering and Networks Laboratory, Switzerland 4ETH Zürich, Institute of Geodesy and Photogrammetry, Switzerland 5Department of Geography, University of Leicester, United Kingdom 6SensAlpin GmbH, Switzerland 7Federal Office for the Environment FOEN, Switzerland
Radar Interferometric Observations of Destabilized Rockglaciers
Analysis of ERS-1/2 Tandem SAR interferograms for inventorying mass wasting in the periglacial be... more Analysis of ERS-1/2 Tandem SAR interferograms for inventorying mass wasting in the periglacial belt of the Valais Alps (Switzerland) has evidenced - what was not expected before - that at least 10 rockglaciers were affected by very rapid movements of about 1 cm/day in 1995-1999. Currently, the detection of the state of activity of these very rapidly moving rockglaciers is hardly feasible with satellite SAR data, because of signal decorrelation after the 35, 46 and 11 days repeat intervals of the ENVISAT, ALOS and TerraSAR-X satellites, respectively. The role of space-borne radar interferometry as an element in a warning system is thus insignificant for these very rapid landslides, but an insitu radar imaging system can overcome some of the limitations of satellite systems. In this contribution we present results from terrestrial radar interferometric measurements of two destabilized rockglaciers performed in August 2009.
Uploads
Papers by Hugo Raetzo