Mapping slope movements in Alpine environments is an increasingly important task in the context of climate change and natural hazard management. We propose the detection, mapping and inventorying of slope movements using different interferometric methods based on TerraSAR-X satellite images. Differential SAR interferograms (DInSAR), Persistent Scatterer Interferometry (PSI), Short-Baseline Interferometry (SBAS) and a semi-automated texture image analysis are presented and compared in order to determine their contribution for the automatic detection and mapping of slope movements of various velocity rates encountered in Alpine environments. Investigations are conducted in a study region of about 6 km  6 km located in the Western Swiss Alps using a unique large data set of 140 DInSAR scenes computed from 51 summer TerraSAR-X (TSX) acquisitions from 2008 to 2012. We found that PSI is able to precisely detect only points moving with velocities below 3.5 cm/yr in the LOS, with a root mean squared error of about 0.58 cm/yr compared to DGPS records. SBAS employed with 11 days summer interferograms increases the range of detectable movements to rates up to 35 cm/yr in the LOS with a root mean squared error of 6.36 cm/yr, but inaccurate measurements due to phase unwrapping are already possible for velocity rates larger than 20 cm/year. With the semi-automated texture image analysis the rough estimation of the velocity rates over an outlined moving zone is accurate for rates of ''cm/day", ''dm/month" and ''cm/month", but due to the decorrelation of yearly TSX interferograms this method fails for the observation of slow movements in the ''cm/yr" range..

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L'influence des actions anthropiques dans l'évolution historique d'un littoral sableux à forte dérive sédimentaire : la baie de Port-Bouët (Abidjan, Côte d'Ivoire)The influence of anthropic actions in the historical coastal evolution of a sandy coast with high sediment drift: the Bay of Port-Bouet (Abidjan, Ivory Coast

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A geographical information system (GIS) is much more than a computerized mapping system, it is a system designed to acquire, to manage and to process spatial information. In the current trend of a multidisciplinary approach of earth environmental management, GIS offer a basis for integrating both data and analysis tools from a broad spectrum of scientific disciplines. This paper aims to present an understanding of concepts and methodologies involved in the field of GIS. It describes major steps involved in processing spatial information and illustrates the diversity among GIS uses. As a GIS is not only a set of computerized tools, but a fully integrated environment for the management and the analysis of spatial information, it requires from the applied fields of geosciences to interrogate about the nature and content of relevant information, as well as about the transfer of classical investigation and analysis methodologies. 0 1997 Elsevier Science B.V.