Search results for "CHANGEMENT"
showing 10 items of 135 documents
A Simple Fusion Method for Image Time Series Based on the Estimation of Image Temporal Validity
2015
High-spatial-resolution satellites usually have the constraint of a low temporal frequency, which leads to long periods without information in cloudy areas. Furthermore, low-spatial-resolution satellites have higher revisit cycles. Combining information from high- and low- spatial-resolution satellites is thought a key factor for studies that require dense time series of high-resolution images, e.g., crop monitoring. There are several fusion methods in the bibliography, but they are time-consuming and complicated to implement. Moreover, the local evaluation of the fused images is rarely analyzed. In this paper, we present a simple and fast fusion method based on a weighted average of two in…
Croissance et convergence des pays de la zone CFA : une étude par les données de panel non stationnaires
2011
During the recent years, african countries in the CFA zone have experienced many economic changes on the one hand through the measures initiated by bilateral and multilateral donors and on the other hand through the economic and monetary integration policies. Thus, relying on the assumption that because of these interventions, the economic systems incorporate various phenomena such as structural change and economic interdependencies, we studied their major implications on growth, convergence and growth predictability. Emphasis is first placed on the major features of integration policies in a monetary union, while stressing the possible implications of such policies on the economic dynamics…
What is a tree in the Mediterranean Basin hotspot? A critical analysis
2019
Background: Tree species represent 20% of the vascular plant species worldwide and they play a crucial role in the global functioning of the biosphere. The Mediterranean Basin is one of the 36 world biodiversity hotspots, and it is estimated that forests covered 82% of the landscape before the first human impacts, thousands of years ago. However, the spatial distribution of the Mediterranean biodiversity is still imperfectly known, and a focus on tree species constitutes a key issue for understanding forest functioning and develop conservation strategies. Methods: We provide the first comprehensive checklist of all native tree taxa (species and subspecies) present in the Mediterranean-Europ…
Le paysage, entre esthétique & écologie : modélisation rétrospective à partir de changements d'occupation du sol
2016
Landscape is both a backdrop to the lives of human populations and a medium for the life cycle of animal species. Landscape changes induced by land-use and land-cover dynamics affect both these dimensions, the one aesthetic, and the other ecological. Because these rationales areusually studied within different disciplines, little research has been done into how the two clashor combine as and when landscape structures change. This work seeks therefore to model the spatial co-evolution of the aesthetic and ecological functions of landscape retrospectively usingspatial metrics based on land-cover data. It focuses on changes in the urban fringes of two French cities (Paris and Besançon) over th…
Erosion des sols viticoles et adaptation aux changements : vulnérabilité, diagnostic et stratégie d'adaptation. De l’adaptation des pratiques à la ré…
2018
International audience
Sensibilité de la réserve en eau des sols de Bourgogne pour une année climatique (2003) représentative du climat futur
2009
National audience; L'étude porte sur l'adaptation au changement climatique en Bourgogne. Elle vise à définir la sensibilité de la ressource en eau des territoires Bourguignons à ces évolutions climatiques et à en estimer les incidences par secteurs géographiques et d'activité. Ce projet pluri-disciplaire a été mis en place par Alterre Bourgogne dont la tache a été de fédérer un réseau d'acteurs régionaux aux compétences variées : climatologie, pédologie et hydrologie. La première étape, (Ubertosi et al, GFHN 2009), a consisté à estimer la capacité des sols à stocker de l'eau, c'est-à-dire à calculer la taille de leur réserve utile. Ces calculs ont été réalisés à partir du référentiel pédolo…
OntoVersionGraph : a change management methodology dedicated to formal ontologies and their user views in a collaborative context
2014
The world changes over time, impacting the knowledge of every subdomain it contains. Therefore systems describing the knowledge of a certain domain should be able to consider changes occurred to keep its knowledge representation up-to-date. Formal ontologies are one of them: they explicitly and formally represent the knowledge of a domain in all its forms and modes of existence. Collaboratively developed, a formal ontology allows the domain users to understand each other by sharing the same terminology despite the different assumptions they have on the domain conceptualization. However, due to its completeness, the complexity of its conceptualization can sometimes make the domain knowledge …
Retrievals of soil moisture and optical depth from CAROLS
2011
International audience; We propose in this paper to evaluate a method to retrieve soil moisture (SM) and vegetation optical thickness, in areas of unknown roughness and unknown vegetation water content in view of operational applications, by using airborne Tb measurements acquired in South-West of France. Results are compared to in situ measurements, manual and automatic ones included in SMOSmania network, in the South-West of France.
Exploitation des données d’épidémio-surveillance des adventices
2013
Session 3 - Surveillance biologique du territoire : de l'observation à la décisionSPEEcolDur; L’épidémio-surveillance (ES) des espèces adventices n’a pas le même statut que celle conduite classiquement pour les maladies ou les insectes car elle ne vise que peu à piloter les besoins de lutte en cours de saison selon la météorologie. Pour autant, elle permet de rapprocher les caractéristiques du système de culture et la flore hébergée. A ce titre, les données issues de l’ES des adventices permettent de préciser la flore attendue dans un contexte local donné caractérisé par un sol un climat et un itinéraire. Comme les adventices réagissent fortement aux changements de leur environnement, l’ES …
Variations spatiales et temporelles de communautés adventices des cultures annuelles en France
2010
Résumé de thèse; National audience