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Of the many tree species that grow in Alsace forest, chestnut trees are considered as promising and adapted to the challenge of global warning. This species has been the focus of a joint French-German Interreg IV study. This three-year study's objective was to develop conservation strategies and to valorize the sweet chestnut. Therefore, it has focused on conservation, on wood and fruit use, and on sweet chestnut preservation as they are faced a canker disease that threatens the forest stands. Within this project, a method has been developed for the precise and up-to-date mapping of chestnut stands throughout Alsace. To distinguish chestnut from other species, the method is based on a targeted selection of satellite images acquired at different seasons and field plot data geo-locating chestnut trees. Thus, SPOT 5 and ALOS AVNIR-2 multi temporal images covering the chestnut tree vegetative phases were used. The study is based on the multi-temporal spectral characteristic analysis of the main deciduous species using field samples. In this way, the spectral signature analysis identified images acquired in early spring and in summer as differentiating chestnut trees. They correspond to the particular characteristics of this species which are its late bud break compared to other species and its abundant flowering. The results of this mapping covering the whole of the Alsace region were validated during field campaigns. This partial validation has shown an accuracy of detection concerning mature chestnut stands of 85%. [ABSTRACT FROM AUTHOR]

This paper explores the potential of the Pléiades images for the monitoring of the recolonization of Maido Forest in a post-fire framework. This site, located in the heart of the National Park of Reunion and classified as a UNESCO World Heritage Site, has been affected by several wildfires late October 2011, ravaging an area of approximately 2700 ha covered mostly by endemic species. To understand the state and the phenological behavior of pre and post fire vegetation, this study uses the SPOT KALIDEOS archive (since 2005) combined with field information. Then, a series of post-fire Pleiades image acquired from June 2012 to September 2013 plus one pre-event Worldview-2 image were used to assess the contribution of very high spatial resolution to monitor forest recolonization at a plot scale. A total of 66 SPOT and 10 very high resolution (Pléiades and WorldView-2) images have been integrated and exploited. Spectral vegetation indexes like NDVI or TSAVI have been analyzed on multi-temporal series and have highlighted the forest vegetation cycle as well as outside perturbation phases than closer to the event and after. The NRI index allowed characterization and monitoring of post-fire vegetation recolonization. Finally, the texture provided by the very high resolution images helped to confirm vegetation recovery and to qualify this recolonization phenomenon consisting of a vegetation apparently different from the original. [ABSTRACT FROM AUTHOR]

Rapid mapping of disasters using any kind of satellite imagery is a challenge. The faster the response, the better the service is for the end users who are managing the emergency activities. Indeed, production rapidity is crucial whatever the satellite data in input. However, the speed of delivery must not be at the expense of crisis information quality. The automated flood and fire extraction pipelines, presented in this technical note, make it possible to take full advantage of advanced algorithms in short timeframes, and leave enough time for an expert operator to validate the results and correct any unmanaged thematic errors. Although automated algorithms aren't flawless, they greatly facilitate and accelerate the detection and mapping of crisis information, especially for floods and fires. ExtractEO is a pipeline developed by SERTIT and dedicated to disaster mapping. It brings together automatic data download and pre-processing, along with highly accurate flood and fire detection chains. Indeed, the thematic quality assessment revealed F1-score values of 0.91 and 0.88 for burnt area and flooded area detection, respectively, from various kinds of high- and very-high- resolution data (optical and SAR). [ABSTRACT FROM AUTHOR]

La configuration d'acquisition tri-stéréoscopique des satellites Pléiades-HR permet de fournir trois images acquises avec des points de vue différents, autorisant la reconstruction de la scène observée par des techniques classiques de stéréophotogrammétrie. Une comparaison d'un Modèle Numérique de Surface Pléiades-HR avec un relevé LiDAR est présentée. Puis les potentialités applicatives des modèles numériques de surface sont investiguées à travers l'analyse de produits destinés à alimenter des études en cours sur diverses thématiques. [ABSTRACT FROM AUTHOR]

Within the Thematic User Commissioning for the VHR Pléiades valorization, imagery was tasked in emergency following disaster events or user-exercise at the request of French Ministries (Ministry of the Environment, Ministry of Finance). These activities were also aimed at familiarizing French institutional users with the use of space technologies within crisis event management. One long term objective would be to set up a national capacity for these users, outside of the International Charter 'Space and Major Disasters' and Copernicus scope which did not support all the needs of the French Ministries. In March and May 2013, in coordination with CNES, SERTIT, SCHAPI, IGN and CEREMA, some Pléiades data have been tasked and processed in rush mode for the case of the Agly, Yonne and Marne 2013 flood events. In June 2013, two new rapid mapping actions have been carried out by CNES and SERTIT. The first one, liaising with the SCHAPI and the Rhin Sarre Flood Forecast Service (DREAL Alsace) for the Sarre river flooding, and the second one in coordination with the French State reinsurance company (Caisse Centrale de Réassurance) over the Gave de Pau floods. Finally, in February 2013, the exercise "SEISME 13" was performed at the request of the crisis center of the Ministry of the Environment (SG/SDSIE/CMVOA). Regarding user's needs, the objectives concerned water surface detection, dyke breaks, affected built features. In the case of rapid floods as Agly and Gave de Pau events, images analysis also included the recognition of residual flood water surfaces, mud deposits and current flows. In addition, the Agly case mapping got the benefits to flood mapping that can be derived from a Pléiades stereoscopic pair. For "SEISME 13" Exercise, the value added products took into account the specific needs expressed by the Ministries of the Environment, Transport and Health (damages to infrastructure, network, and building). [ABSTRACT FROM AUTHOR]