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Trame verte et bleue : bilan des besoins, enjeux et actions de connaissance identifiés par les Schémas régionaux de cohérence écologique / Romain Sordello in Naturae, n° 10 ([26/07/2017])
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Titre : Trame verte et bleue : bilan des besoins, enjeux et actions de connaissance identifiés par les Schémas régionaux de cohérence écologique Type de document : Article/Communication Auteurs : Romain Sordello, Auteur Année de publication : 2017 Article en page(s) : pp 1 - 22 Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Ecologie
[Termes IGN] changement climatique
[Termes IGN] continuité écologique
[Termes IGN] espèce exotique envahissante
[Termes IGN] migration animale
[Termes IGN] politique publique
[Termes IGN] pollution lumineuse
[Termes IGN] réseau de transport
[Termes IGN] schéma régional de cohérence écologique
[Termes IGN] trame verte et bleueRésumé : (auteur) La Trame verte et bleue (TVB) est une politique française du ministère de l’Environnement visant à préserver et restaurer un réseau de continuités écologiques, notamment à l’échelle régionale par l’intermédiaire des Schémas régionaux de cohérence écologique (SRCE). Pour ce faire, des connaissances sont nécessaires, à la fois fondamentales et pratiques. Ce travail présente un bilan des lacunes, enjeux et actions de connaissance mis en évidence par les SRCE. Une catégorisation par thème a permis de relever les éléments récurrents sur l’ensemble des régions. Les besoins en connaissance primaire (espèces, habitats naturels, etc.) s’avèrent très importants. Ils relèvent à la fois de l’acquisition de connaissances nouvelles et d’une meilleure organisation des informations existantes. Ils concernent par ailleurs des données et des connaissances fondamentales. Ces manques ont contraint l’identification des continuités écologiques régionales. De même, la qualification de leur fonctionnalité et le repérage des obstacles nécessitent des connaissances qui ont souvent fait défaut. Plusieurs thèmes ressortent également comme fortement concernés par des besoins ou des actions. En premier lieu viennent les infrastructures de transport puis le changement climatique, les espèces exotiques envahissantes, les voies de migration de l’avifaune ou encore la pollution lumineuse. Cet état des lieux offre une vue d’ensemble sur les besoins de connaissance pour établir, préciser et mettre en œuvre la TVB à l’échelle des 21 ex-régions métropolitaines. À ce titre, il peut être utile aux équipes de recherche ou à celles impliquées dans le transfert de connaissances, aux programmes producteurs de données ainsi qu’aux organismes porteurs d’appels à projet. Numéro de notice : A2017-679 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : sans En ligne : http://sciencepress.mnhn.fr/sites/default/files/articles/pdf/naturae-10-pdf.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87218
in Naturae > n° 10 [26/07/2017] . - pp 1 - 22[article]Documents numériques
en open access
Trame verte et bleueAdobe Acrobat PDFPerformance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station / G. Sivavaraprasad in Advances in space research, vol 60 n° 2 (15 July 2017)
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Titre : Performance evaluation of ionospheric time delay forecasting models using GPS observations at a low-latitude station Type de document : Article/Communication Auteurs : G. Sivavaraprasad, Auteur ; D. Venkata Ratman, Auteur Année de publication : 2017 Article en page(s) : pp 475 - 490 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] Inde
[Termes IGN] International Reference Ionosphere
[Termes IGN] latitude
[Termes IGN] modèle de simulation
[Termes IGN] modèle ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] teneur totale en électrons
[Termes IGN] teneur verticale totale en électrons
[Termes IGN] test de performance
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Ionospheric delay is one of the major atmospheric effects on the performance of satellite-based radio navigation systems. It limits the accuracy and availability of Global Positioning System (GPS) measurements, related to critical societal and safety applications. The temporal and spatial gradients of ionospheric total electron content (TEC) are driven by several unknown priori geophysical conditions and solar-terrestrial phenomena. Thereby, the prediction of ionospheric delay is challenging especially over Indian sub-continent. Therefore, an appropriate short/long-term ionospheric delay forecasting model is necessary. Hence, the intent of this paper is to forecast ionospheric delays by considering day to day, monthly and seasonal ionospheric TEC variations. GPS-TEC data (January 2013–December 2013) is extracted from a multi frequency GPS receiver established at K L University, Vaddeswaram, Guntur station (geographic: 16.37°N, 80.37°E; geomagnetic: 7.44°N, 153.75°E), India. An evaluation, in terms of forecasting capabilities, of three ionospheric time delay models – an Auto Regressive Moving Average (ARMA) model, Auto Regressive Integrated Moving Average (ARIMA) model, and a Holt-Winter's model is presented. The performances of these models are evaluated through error measurement analysis during both geomagnetic quiet and disturbed days. It is found that, ARMA model is effectively forecasting the ionospheric delay with an accuracy of 82–94%, which is 10% more superior to ARIMA and Holt-Winter’s models. Moreover, the modeled VTEC derived from International Reference Ionosphere, IRI (IRI-2012) model and new global TEC model, Neustrelitz TEC Model (NTCM-GL) have compared with forecasted VTEC values of ARMA, ARIMA and Holt-Winter’s models during geomagnetic quiet days. The forecast results are indicating that ARMA model would be useful to set up an early warning system for ionospheric disturbances at low latitude regions. Numéro de notice : A2017-252 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2017.01.031 Date de publication en ligne : 30/01/2017 En ligne : https://doi.org/10.1016/j.asr.2017.01.031 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85254
in Advances in space research > vol 60 n° 2 (15 July 2017) . - pp 475 - 490[article]Adaptive and plastic responses of Quercus petraea populations to climate across Europe / Cuauhtémoc Saenz-Romero in Global change biology, vol 23 n° 7 (July 2017)
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Titre : Adaptive and plastic responses of Quercus petraea populations to climate across Europe Type de document : Article/Communication Auteurs : Cuauhtémoc Saenz-Romero, Auteur ; Jean-Baptiste Lamy, Auteur ; Alexis Ducousso, Auteur ; Brigitte Musch, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 2831 - 2847 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] changement climatique
[Termes IGN] Danemark
[Termes IGN] forêt tempérée
[Termes IGN] France (administrative)
[Termes IGN] Hongrie
[Termes IGN] modèle de simulation
[Termes IGN] Norvège
[Termes IGN] Quercus sessiliflora
[Termes IGN] Turquie
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) How temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak (Quercus petraea), a widespread keystone European forest tree species, including more than 150 000 trees sourced from 116 geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (i) to identify the source of differential population responses to climate (genetic differentiation due to past divergent climatic selection vs. plastic responses to ongoing climate change) and (ii) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071–2100, using two greenhouse gas concentration trajectory scenarios each. Overall, results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual or during the growing season) explaining the major part of the response. While, on average, populations exhibited local adaptation, there was significant clinal population differentiation for height growth with winter temperature at the site of origin. The most moderate climate model (HIRHAM5-EC; rcp4.5) predicted minor decreases in height and survival, while the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other nonmarginal populations with continental climates were predicted to be severely and negatively affected (Bercé, France), while populations at the contemporary northern limit (colder and humid maritime regions; Denmark and Norway) will probably not show large changes in growth and survival in response to climate change. Numéro de notice : A2017-676 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1111/gcb.13576 En ligne : http://doi.org/10.1111/gcb.13576 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87202
in Global change biology > vol 23 n° 7 (July 2017) . - pp 2831 - 2847[article]Fusing tree‐ring and forest inventory data to infer influences on tree growth / Margaret E.K. Evans in Ecosphere, vol 8 n° 7 (July 2017)
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Titre : Fusing tree‐ring and forest inventory data to infer influences on tree growth Type de document : Article/Communication Auteurs : Margaret E.K. Evans, Auteur ; Donald A. Falk, Auteur ; et al., Auteur Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] changement climatique
[Termes IGN] classification bayesienne
[Termes IGN] croissance des arbres
[Termes IGN] dendrochronologie
[Termes IGN] inférence statistique
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] modèle statistique
[Termes IGN] montagne
[Termes IGN] Nouveau-Mexique (Etats-Unis)
[Termes IGN] régression multiple
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Better understanding and prediction of tree growth is important because of the many ecosystem services provided by forests and the uncertainty surrounding how forests will respond to anthropogenic climate change. With the ultimate goal of improving models of forest dynamics, here we construct a statistical model that combines complementary data sources, tree‐ring and forest inventory data. A Bayesian hierarchical model was used to gain inference on the effects of many factors on tree growth—individual tree size, climate, biophysical conditions, stand‐level competitive environment, tree‐level canopy status, and forest management treatments—using both diameter at breast height (dbh) and tree‐ring data. The model consists of two multiple regression models, one each for the two data sources, linked via a constant of proportionality between coefficients that are found in parallel in the two regressions. This model was applied to a data set of ~130 increment cores and ~500 repeat measurements of dbh at a single site in the Jemez Mountains of north‐central New Mexico, USA. The tree‐ring data serve as the only source of information on how annual growth responds to climate variation, whereas both data types inform non‐climatic effects on growth. Inferences from the model included positive effects on growth of seasonal precipitation, wetness index, and height ratio, and negative effects of dbh, seasonal temperature, southerly aspect and radiation, and plot basal area. Climatic effects inferred by the model were confirmed by a dendroclimatic analysis. Combining the two data sources substantially reduced uncertainty about non‐climate fixed effects on radial increments. This demonstrates that forest inventory data measured on many trees, combined with tree‐ring data developed for a small number of trees, can be used to quantify and parse multiple influences on absolute tree growth. We highlight the kinds of research questions that can be addressed by combining the high‐resolution information on climate effects contained in tree rings with the rich tree‐ and stand‐level information found in forest inventories, including projection of tree growth under future climate scenarios, carbon accounting, and investigation of management actions aimed at increasing forest resilience. Numéro de notice : A2017-907 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1002/ecs2.1889 Date de publication en ligne : 24/07/2017 En ligne : https://doi.org/10.1002/ecs2.1889 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93405
in Ecosphere > vol 8 n° 7 (July 2017)[article]Improving the modeling of the atmospheric delay in the data analysis of the Intensive VLBI sessions and the impact on the UT1 estimates / Tobias Nilsson in Journal of geodesy, vol 91 n° 7 (July 2017)
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Titre : Improving the modeling of the atmospheric delay in the data analysis of the Intensive VLBI sessions and the impact on the UT1 estimates Type de document : Article/Communication Auteurs : Tobias Nilsson, Auteur ; Benedikt Soja, Auteur ; Kyriakos Balidakis, Auteur ; Maria Karbon, Auteur ; Robert Heinkelmann, Auteur ; Zhiguo Deng, Auteur ; Harald Schuh, Auteur Année de publication : 2017 Article en page(s) : pp 857 - 866 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse de données
[Termes IGN] filtre de Kalman
[Termes IGN] gradient de troposphère
[Termes IGN] interférométrie à très grande base
[Termes IGN] longueur du jour
[Termes IGN] modèle atmosphérique
[Termes IGN] retard troposphérique zénithal
[Termes IGN] temps universelRésumé : (Auteur) The very long baseline interferometry (VLBI) Intensive sessions are typically 1-h and single-baseline VLBI sessions, specifically designed to yield low-latency estimates of UT1-UTC. In this work, we investigate what accuracy is obtained from these sessions and how it can be improved. In particular, we study the modeling of the troposphere in the data analysis. The impact of including external information on the zenith wet delays (ZWD) and tropospheric gradients from GPS or numerical weather prediction models is studied. Additionally, we test estimating tropospheric gradients in the data analysis, which is normally not done. To evaluate the results, we compared the UT1-UTC values from the Intensives to those from simultaneous 24-h VLBI session. Furthermore, we calculated length of day (LOD) estimates using the UT1-UTC values from consecutive Intensives and compared these to the LOD estimated by GPS. We find that there is not much benefit in using external ZWD; however, including external information on the gradients improves the agreement with the reference data. If gradients are estimated in the data analysis, and appropriate constraints are applied, the WRMS difference w.r.t. UT1-UTC from 24-h sessions is reduced by 5% and the WRMS difference w.r.t. the LOD from GPS by up to 12%. The best agreement between Intensives and the reference time series is obtained when using both external gradients from GPS and additionally estimating gradients in the data analysis. Numéro de notice : A2017-298 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0985-7 En ligne : http://doi.org/10.1007/s00190-016-0985-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85333
in Journal of geodesy > vol 91 n° 7 (July 2017) . - pp 857 - 866[article]vol 8 n° 2 - juillet 2017 - Lutte contre le changement climatique et maîtrise de la demande d’énergie (Bulletin de Développement durable & territoire)
PermalinkOptimum stochastic modeling for GNSS tropospheric delay estimation in real-time / Tomasz Hadas in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkPolarGlobe : A web-wide virtual globe system for visualizing multidimensional, time-varying, big climate data / Wenwen Li in International journal of geographical information science IJGIS, vol 31 n° 7-8 (July - August 2017)
PermalinkReal-time precise point positioning augmented with high-resolution numerical weather prediction model / Karina Wilgan in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkReview of code and phase biases in multi-GNSS positioning / Martin Håkansson in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkRobust GPS/BDS/INS tightly coupled integration with atmospheric constraints for long-range kinematic positioning / Houzeng Han in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkStatistical comparison and combination of GPS, GLONASS, and multi-GNSS multipath reflectometry applied to snow depth retrieval / Sajad Tabibi in IEEE Transactions on geoscience and remote sensing, vol 55 n° 7 (July 2017)
PermalinkStudy and mitigation of calibration factor instabilities in a water vapor Raman lidar / Leslie David in Atmospheric measurement techniques, vol 10 n° 7 (July 2017)
PermalinkEffects of urban tree canopy loss on land surface temperature magnitude and timing / Arthur Elmes in ISPRS Journal of photogrammetry and remote sensing, vol 128 (June 2017)
PermalinkIntegrated precipitable water from GPS observations and cimel sunphotometer measurements at CGO Belsk / Michal Kruczyk in Reports on geodesy and geoinformatics, vol 103 n° 1 (June 2017)
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