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modèle dynamiqueSynonyme(s)modèle spatiotemporel dynamique |
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A novel approach for predicting the spatial patterns of urban expansion by combining the chi-squared automatic integration detection decision tree, Markov chain and cellular automata models in GIS / Abubrakr A. A. Al Sharif in Geocarto international, vol 30 n° 7 - 8 (August - September 2015)
[article]
Titre : A novel approach for predicting the spatial patterns of urban expansion by combining the chi-squared automatic integration detection decision tree, Markov chain and cellular automata models in GIS Type de document : Article/Communication Auteurs : Abubrakr A. A. Al Sharif, Auteur ; Biswajeet Pradhan, Auteur Année de publication : 2015 Article en page(s) : pp 858 - 881 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] arbre de décision
[Termes IGN] automate cellulaire
[Termes IGN] croissance urbaine
[Termes IGN] données spatiotemporelles
[Termes IGN] étalement urbain
[Termes IGN] khi carré
[Termes IGN] modèle de simulation
[Termes IGN] modèle dynamique
[Termes IGN] modèle stochastique
[Termes IGN] surveillance de l'urbanisation
[Termes IGN] système d'information géographique
[Termes IGN] Tripoli (Libye ; ville)
[Termes IGN] urbanisationRésumé : (Auteur) Urban development is a continuous and dynamic spatio-temporal phenomenon associated with economic developments and growing populations. To understand urban expansion, it is important to establish models that can simulate urbanization process and its deriving factors behaviours, monitor deriving forces interactions and predict spatio-temporally probable future urban growth patterns explicitly. In this research, therefore, we presented a hybrid model that integrates the chi-squared automatic integration detection decision tree (CHAID-DT), Markov chain (MC) and cellular automata (CA) models to analyse, simulate and predict future urban expansions in Tripoli, Libya in 2020 and 2025. First, CHAID-DT model was applied to investigate the contributions of urban factors to the expansion process, to explore their interactions and to provide future urban probability map; second, MC model was employed to estimate the future demand of urban land; third, CA model was used to allocate estimated urban land quantity on the probability map to present future projected land use map. Three satellite images of the study area were obtained from the periods of 1984, 2002 and 2010 to extract land use maps and urban expansion data. We validated the model with two methods, namely, receiver operating characteristic and the kappa statistic index of agreement. Results confirmed that the proposed hybrid model could be employed in urban expansion modelling. The applied hybrid model overcame the individual shortcomings of each model and explicitly described urban expansion dynamics, as well as the spatio-temporal patterns involved. Numéro de notice : A2015-504 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/URBANISME Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2014.997308 Date de publication en ligne : 10/02/2015 En ligne : http://www.tandfonline.com/doi/full/10.1080/10106049.2014.997308 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77421
in Geocarto international > vol 30 n° 7 - 8 (August - September 2015) . - pp 858 - 881[article]Réservation
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Titre : To die or not to die: Forest dynamics in Switzerland under climate change Type de document : Thèse/HDR Auteurs : Nicolas Bircher, Auteur Editeur : Zurich : Eidgenossische Technische Hochschule ETH - Ecole Polytechnique Fédérale de Zurich EPFZ Année de publication : 2015 Collection : Dissertationen ETH num. 22775 Importance : 188 p. Format : 21 x 30 cm Note générale : bibliographie
A thesis submitted to attain the degree of doctor of sciences of ETH ZurichLangues : Anglais (eng) Descripteur : [Termes IGN] composition floristique
[Termes IGN] dynamique de la végétation
[Termes IGN] forêt alpestre
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] modèle dynamique
[Termes IGN] Picea abies
[Termes IGN] série temporelle
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] Suisse
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) A high diversity of forest ecosystems is found around the globe providing various ecosystem services to humans. Responses of forests to recent increases of drought events have given rise to serious concerns about future forest development. Since anthropogenic climate change is proceeding at an unprecedented rate, the forestry sector is challenged to swiftly develop and plan adaptive management measures that guarantee the sustainable provision of forest ecosystem services in the future. The planning of management strategies is strongly dependent on reliable knowledge on future forest dynamics. To this end, the Swiss government has launched an extensive research program to examine the impact of climate change on Swiss forests. One aim among others is to assess the sensitivity of common forest types of Switzerland to climate change.
Dynamic vegetation models (DVMs) are suitable to provide quantitative assessments of forest sensitivity to climate change, as their flexibility allows considering dynamic vegetation transitions under conditions that do not represent a steady state. Among DVMs, forest gap models portray long-term forest dynamics at the stand scale taking biotic interactions such as competition into account. Recent integration of sophisticated management techniques has substantially extended their range of application from unmanaged to complex mixed-species forests under management, thus making them interesting tools for the assessment of climate change impacts on forest ecosystems. However, forest gap models integrate a large number of ecological processes that still lack an empirical base. This is particularly true for tree mortality – a key demographic process in forest dynamics – where increasing empirical research has been followed by little action in DVMs. Thus, although it is widely acknowledged that empirical functions should be integrated into DVMs to enhance ecological realism, little is known about whet her this approach leads to an increased robustness of model projections.
Given this background, my thesis includes two major objectives: 1) to examine the potential of empirical mortality functions in dynamic vegetation models and 2) to assess the sensitivity of common Swiss forests to climate change.
In Chapter 1 of this thesis, I implemented an inventory- and a tree-ring based mortality function in the forest gap model ForClim and combined them with a stochastic and a deterministic approach for the determination of tree status (alive vs. dead). These four new model versions were tested for two Norway spruces stands, one of which was managed (inventory time series of 72 years) and the other was unmanaged (41 years). Furthermore, I ran long-term simulations (~400 years) into the future to test model behavior under three climate scenarios. I showed that three out of the four mode l versions showed good agreement for stand basal area and stem numbers when compared against inventory data of both forest sites. Due to very similar model behavior, an unambiguous choice of a “best” model version was, however, not possible. In contrast, long -term simulations revealed very different behavior of the mortality models, indicating that the choice of the mortality function is crucial for simulated forest dynamics. Based on these results, I concluded that 1) empirical mortality functions are valuable replacements for current theoretical mortality algorithms in dynamic vegetation models 2) but further tests would be needed to rigorously assess their potential and to better understand interactions of the mortality function with other model processes.
Enhanced use of empirical data in dynamic vegetation models is widely advocated. However, it is largely unknown whether empirically derive d functions are compatible with the wide range of processes and interactions that are usually found in DVMs and thus, whether they lead to an better model performance. In Chapter 2 , I addressed this question with the focus on the inventory-based mortality function that has already been used in Chapter 1 . I used Bayesian methods to recalibrate its mortality parameters within ForClim. I compared its performance with the ForClim version containing the original, empirically fitted mortality parameters and with the current ForClim v3.3 that included a theoretical mortality function. Calibration and subsequent validation was based on inventory data of 30 Swiss natural forest reserves. Similarities between the calibrated and the empirically fitted mortality parameters suggest that the general structure of ForClim is appropriate to integrate empirical mortality functions. However, I found some discrepancies that indicate necessary improvements regarding the role of species’ shade tolerance in growth-mortality relationships and an optimal balance between growth and mortality. Bayesian calibration led to best performance both at calibration and validation sites. Furthermore, it revealed that the sensitivity of ForClim to parametric uncertainty is particularly high for trees in low dbh classes but surprisingly small for standard model outputs such as basal area.
Assessing the sensitivity of common forest stands in Switzerland with a forest gap model makes it necessary 1) to know which forest stands are common and 2) to have suitable data for model initialization. In Chapter 3 , I developed a stratification of the Swiss forest area to identify those forest types of Switzerland that , in terms of their stand structure and tree species composition, are most common in different eco-regions and elevation zones. I used plot data form the third Swiss National Forest Inventory (NFI3) that contained both stand attributes and single-tree data. NFI plots were grouped into eco -regions and elevation zones according to the “Guide for sustainability in protection forests” (NaiS). I further segregated NFI plots into more groups based on two forest stand attributes: vertical stand structure and developmental stage. In a last step, I relied on recommendations of sylvicultural experts for dividing some groups into more strata to strengthen a realistic tree species composition. The stratification resulted in 71 strata that contained 25% of all NFI forest plots. Single-tree data of all NFI plots associated to one stratum were aggregate d. Although the final result is a somewhat “artificial” forest stand, it has the tremendous advantage that NFI plot data can be used directly for stand initialization in the forest gap model ForClim.
In Switzerland, studies on forest sensitivity to climate change often focus on extreme sites where shifts in tree species composition are already visible while less attention is paid to the fate of common forest stands that are most important for Swiss forestry. In Chapter 4, I ran simulations for 71 strata that had been identified in the previous chapter using two model versions to examine their development until the end of the 21 st century (year 2100). Simulations were run with common Swiss forest management strategies and without management. I considered forest development under current climate (1980-2009) and under 11 different climate change scenarios assuming an A2 greenhouse gas emission scenario. According to these simulation results, shifts in structure and composition of Swiss forests have to be expected for the second half of this century. However, high variability among the strata was found due to drivers of small-scaled forest dynamics such as regional climate, elevation gradients and current species composition. I showed that current management regimes can alleviate the negative impacts of climate change but adaptive measures are necessary to be applied at a site-specific and objective-oriented base. In conclusion, model- based assessments on forest sensitivity can only provide reliable decision-making support for forest managers if small-scaled drivers of forest stand dynamics are take n into consideration.
In the Synthesis, I reflect the findings of the previous chapters by discussing the potential of empirical mortality functions in DVMs and the use of forest gap models – as one type of DVM – as tools for decision-support regarding forest management under climate change. I come to the conclusion that empirical mortality functions are capable to further improve the performance of DVMs and to increase our confidence in their projections. However, empirical functions come with limitations, which might constrain avalid applicability. For this reason, I advocate not to focus on one individual function but to aggregate knowledge on mortality mechanism and data from various sources to enhance the validity of the tree mortality mechanism in DVMs beyond individual empirical data sets. Climate change is expected to have strong effects on future development of current Swiss forests at various sites. High variability in forest response to a changing environment underlines the need to plan future forest strategies at the local scale. Forest gap models have limitations that need to be discussed and tackled. Still, I am convinced that they have the potential to play a key role in decision-making processes as they can provide what decision makers need: a comprehensive reflection of essential processes and an adequate spatial resolution.Numéro de notice : 17200 Affiliation des auteurs : non IGN Thématique : FORET Nature : Thèse étrangère Note de thèse : doctoral thesis : Sciences : ETH Zurich : 2015 En ligne : http://dx.doi.org/10.3929/ethz-a-010596194 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81176 Dynamic modeling of GNSS troposphere wet delay for estimation of precipitable water vapour / Ahmed El-Mowafy in Journal of applied geodesy, vol 8 n° 1 (April 2014)
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Titre : Dynamic modeling of GNSS troposphere wet delay for estimation of precipitable water vapour Type de document : Article/Communication Auteurs : Ahmed El-Mowafy, Auteur ; Johnny Lo, Auteur Année de publication : 2014 Article en page(s) : pp 31 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] autocorrélation
[Termes IGN] humidité de l'air
[Termes IGN] modèle dynamique
[Termes IGN] positionnement par GNSS
[Termes IGN] précipitation
[Termes IGN] propagation troposphérique
[Termes IGN] signal GNSS
[Termes IGN] vapeur d'eauRésumé : (Auteur) Proper dynamic modelling of the troposphere wet delay using the Global Navigation Satellite Systems (GNSS) measurements is important in precise point positioning and in estimation of the Precipitable Water Vapour (PWV) for weather forecast. The random walk (RW) and the first-order Gauss-Markov (GM) autocorrelation models are commonly used for this purpose. However, it was found that these models consistently underestimate the temporal correlations that exist among the troposphere wet delay. Therefore, a new dynamic model is proposed. The performance of the proposed model in following the autocorrelation of actual data is demonstrated and its impact on the near-real time estimation of the wet delay was tested and compared to that of the GM and RW models. Results showed that the proposed model outperformed these models. When the computed wet delays were used to compute PWV, their estimated valueswere very close to actual PWV data measured by radiosonde with differences less than 1 mm. Numéro de notice : A2014-271 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2013-0012 2 2 total citations on Dimensions. Date de publication en ligne : 08/04/2014 En ligne : https://doi.org/10.1515/jag-2013-0012 2 2 total citations on Dimensions. Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33174
in Journal of applied geodesy > vol 8 n° 1 (April 2014) . - pp 31 - 42[article]Outils méthodologiques pour l'analyse d'images MSG : estimation du mouvement, suivi des masses nuageuses et détection de fronts / Thomas Corpetti in Revue Française de Photogrammétrie et de Télédétection, n° 205 (Janvier 2014)
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Titre : Outils méthodologiques pour l'analyse d'images MSG : estimation du mouvement, suivi des masses nuageuses et détection de fronts Type de document : Article/Communication Auteurs : Thomas Corpetti, Auteur ; Vincent Dubreuil, Auteur ; Etienne Mémin, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 3 - 17 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] assimilation des données
[Termes IGN] image Météosat
[Termes IGN] modèle dynamique
[Termes IGN] nuage
[Termes IGN] phénomène atmosphérique
[Termes IGN] phénomène météorologique
[Termes IGN] ventRésumé : (Auteur) Cet article présente les travaux que nous avons menés ces dernières années autour de l’analyse d’images Météosat Seconde Génération (MSG). Comparés à la première génération, les données MSG possèdent une résolution spatiale et temporelle plus élevée, autorisant l’accès à un certain nombre d’informations liées aux phénomènes climatiques observés. Cependant, l’étape consistant à remonter à cette information physique à partir des données images s’avère délicate car nous sommes confrontés à des structures soumises à de très fortes déformations, parfois observées en transparence et avec une durée de vie variable. Par conséquent, les outils classiques issus de l’analyse d’images se révèlent souvent limités et il est nécessaire de les adapter à cette spécificité. Nous nous focalisons ici sur trois applications particulières : l’estimation du mouvement, permettant de remonter aux vents atmosphériques, le suivi de masses nuageuses, autorisant par exemple l’analyse de phénomènes convectifs et la détection de fronts, appliquée ici aux brises de mer. Numéro de notice : A2014-546 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.52638/rfpt.2014.11 En ligne : https://doi.org/10.52638/rfpt.2014.11 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74173
in Revue Française de Photogrammétrie et de Télédétection > n° 205 (Janvier 2014) . - pp 3 - 17[article]Paysans et pasteurs sur les marches du Levant Sud / Claudine Dauphin in Géomatique expert, n° 95 (01/11/2013)
[article]
Titre : Paysans et pasteurs sur les marches du Levant Sud Type de document : Article/Communication Auteurs : Claudine Dauphin, Auteur ; Mohamed Ben Jeddou, Auteur ; Jean-Marie Castex, Auteur Année de publication : 2013 Article en page(s) : pp 30 - 53 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] analyse diachronique
[Termes IGN] base de données localisées
[Termes IGN] densité de population
[Termes IGN] désert
[Termes IGN] données démographiques
[Termes IGN] données environnementales
[Termes IGN] données spatiotemporelles
[Termes IGN] fouille archéologique
[Termes IGN] histoire
[Termes IGN] Jordanie
[Termes IGN] Levant
[Termes IGN] migration humaine
[Termes IGN] modèle dynamique
[Termes IGN] nomadisme
[Termes IGN] Palestine
[Termes IGN] répartition géographique
[Termes IGN] site archéologique
[Termes IGN] surface cultivée
[Termes IGN] système d'information géographique
[Termes IGN] voie antiqueRésumé : (Auteur) Entre la côte méditerranéenne de la Palestine et l'immense désert de la Transjordanie du Sud s'étend une vaste zone-tampon semi-aride. Bissectée par la faille du Jourdain (Ghôr), cette zone de transition entre désert et terres arables, entre climats subtropical méditerranéen et continental aride, fut sujette à divers modes d'interaction entre paysans et pasteurs du crépuscule de l'empire byzantin (fin du VIe siècle et début du VIIe siècle) au sultanat mamelouk (VIe-XVIe siècle) : sédentarisme, infiltration nomade, semi-sédentarisme, sédentarisation, retour au nomadisme et installation temporaire dans le cadre du pèlerinage à La Mecque. Associant SIG et interprétation traditionnelle archéo-historique du passé, notre nouvelle approche géo-spatiale révèle, sur dix siècles, les fluctuations de la dynamique du peuplement de la Palestine et de la Transjordanie méridionales et décèle les changements dans les paysages de terres arables et de désert. Nous présentons ici les avancées depuis 2011 du projet "Sédentaires et nomades", et en particulier, les résultats des analyses statistiques et spatiales à la lumière des fractures historiques du Levant Sud de la Conquête musulmane à l'émergence des Mamelouks. Numéro de notice : A2013-655 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32791
in Géomatique expert > n° 95 (01/11/2013) . - pp 30 - 53[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 265-2013061 RAB Revue Centre de documentation En réserve L003 Disponible IFN-001-P001517 PER Revue Nogent-sur-Vernisson Salle périodiques Disponible PermalinkAn improved empirical model for the effect of long-period ocean tides on polar motion / Richard S. Gross in Journal of geodesy, vol 83 n° 7 (July 2009)PermalinkAssimilation of SPOT-Vegetation NDVI data into a Sahelian vegetation dynamics model / Lionel Jarlan in Remote sensing of environment, vol 112 n° 4 (15/04/2008)PermalinkModelling landscape dynamics with Python / D. Karssenberg in International journal of geographical information science IJGIS, vol 21 n° 5 (may 2007)PermalinkImplementing a new model for simulating processes / F. Reitsma in International journal of geographical information science IJGIS, vol 19 n° 10 (november 2005)PermalinkDynamic environmental modelling in GIS: 2. Modelling error propagation / D. Karssenberg in International journal of geographical information science IJGIS, vol 19 n° 6 (july 2005)PermalinkDynamic environmental modelling in GIS: 1. modelling in three spatial dimensions / D. Karssenberg in International journal of geographical information science IJGIS, vol 19 n° 5 (may 2005)PermalinkAAMAS'05, fifth European workshop on adaptive agents and multi-agent systems, March 21 - 22, 2005, Paris, France / Eduardo Alonso (2005)PermalinkEvent-oriented approaches to geographic phenomena / Michael F. Worboys in International journal of geographical information science IJGIS, vol 19 n° 1 (january 2005)PermalinkAtmosphärische und ozeanische Einflüsse auf die Rotation der Erde - Nummerische Untersuchungen mit einem dynamischen Erdsystemmodell / Florian Seitz (2004)Permalink