La gestion agroécologique durable des paysages agricoles constitue un très fort enjeu social, écologique et économique. Favoriser les différents services écosystémiques que fournissent ces systèmes complexes, caractérisés par une forte variabilité spatio-temporelle liée aux activités anthropiques, est désormais crucial. Le travail développé dans cette thèse s’est focalisé sur les services de régulation des populations de ravageurs, en développant des modèles spatialisés destinés à identifier les interactions entre paysage et populations dans l’optique d’une gestion intégrée du paysage agricole. L’approche conceptuelle utilisée s’est appuyée sur une réflexion sur les choix de niveaux d’organisation et d’échelles spatio-temporelles pertinentes qui a conduit au développement de deux modèles imbriqués : un simulateur de paysages agricoles (ATLAS) reproduisant la variabilité spatio-temporelle des habitats et un automate cellulaire décrivant les dynamiques pluriannuelles d’un puceron des céréales : Rhopalosiphum padi. Une analyse statistique des résultats a permis d’identifier l’effet des différents paramètres du paysage (composition et climat) sur les densités de pucerons à différentes échelles spatiales au cours des saisons. Ont également été évalués les effets potentiels de différents scénarios de gestion plausibles au sein du paysage agricole étudié. Parmi nos résultats, nous identifions que le remplacement du maïs par le sorgho dans le sud-ouest de la France pourrait conduire à une augmentation des densités de R.padi au sein du paysage au printemps, période particulièrement sensible aux infestations. Nous replaçons ce travail dans le cadre plus large de la favorisation des services écosystémiques et apportons des premiers éléments de réflexion pour une gestion durable du paysage agricole; / Sustainable management of agricultural landscapes is a strong social, ecological and economic challenge. Favouring the different ecosystem services provided by these complex systems, characterized by a strong spatio-temporal variability linked to human activity, is by now crucial. The work developed in this thesis has focused on pest population regulation services, by developing spatialized models in order to identify the interactions between the landscape and populations in the context of an integrated management of the agricultural landscape. The conceptual approach we used is based on careful selection of the levels of organization and spatio-temporal scales which lead to the development of two embedded models: an agricultural landscape simulator (ATLAS) reproducing the spatial-temporal variability of habitats and a cellular automaton describing thepluriannual dynamics of a cereal aphid: Rhopalosiphum padi. A statistical analysis of the results highlighted the effects of different landscape parameters (composition and climate) on aphid densities at different spatial scales throughout the seasons. The potential effects of plausible management scenarios were also evaluated. Amongst our results, we identify the replacement of corn by sorghum in the south-western part of France to potentially lead to higher aphid densities within the landscape in spring, which is a season specifically sensible to infestations. We replace this work in the larger context of favouring ecosystem services and propose new ideas for a sustainable management of agricultural landscapes;

Place has been a fundamental topic for geographers (Agnew, 1987). It stands both for a study object and a manner of perceiving the world. This thesis departs from the theoretical debate regarding places and how places are considered as being spatially fixed in the sense that places cannot be reproduced or imitated elsewhere. However, technological innovations have extraordinary significance in all the realms of leisure and lifestyle (Godbey, 1997) whereas, leisure activities increasingly are being simulated and reproduced exemplifying the new postmodern culture and the ‘post-tourist’ (Urry, 1990). Thus, challenges the spatial fix of places (Shaw & Williams, 2004). There has been little empirical research regarding artificial environments and therefore, the research problem contributes to understand how artificial environments are altering habitual travel patterns regarding the ‘genuine’ or as previous authors have stated, regarding the ‘real thing’. The research questions proposed for the study, directed the researcher to a quantitative approach using the questionnaire as a main source of data collection. The simulated environment that was investigated in the study was the indoor ski slope located in Madrid (Spain). The results showed that the simulated environment is enhancing and intervening the ski activity. For most of the skiers the indoor ski slope is complementing their ski activity in front of the outdoor ski resorts. Furthermore, the facility is recruiting every year a great number of new skiers that after skiing indoors desire to experience the ‘real thing’. Due to the proximity of the facility to the major urban areas, the indoor ski slope is acting as an intervening opportunity and boosting the visitors towards outdoor skiing.

Cette thèse s’intègre dans un contexte où les méthodes utilisées pour la mise en place de suivis environnementaux sont souvent problématiques et peuvent mener à des résultats controversables. L’objectif est de proposer une méthodologie adaptable à la plupart des suivis environnementaux qui permettra aux utilisateurs de produire des suivis scientifiques efficaces ou d’optimiser des suivis déjà en place. Nous avons développé une méthodologie qui permet à l’utilisateur de fixer la précision qu’il veut sur ses résultats d’estimation et qui lui renvoie un protocole d’échantillonnage optimal associé à un nombre d’unités statistiques à échantillonner. Une fois le nombre de points connu, il est simple d’estimer le coût de mise en place dela procédure d’échantillonnage sélectionnée sur le terrain.Nous sommes partis de la définition même de la performance d’un protocole d’échantillonnage pour élaborer une méthodologie sous forme de procédure séquentielle qui permet de tester, puis de choisir, le protocole le plus performant pour chaque étude. Plus un protocole d’échantillonnage est performant, moins il nécessite d’unités statistiques pour atteindre une précision voulue. La méthodologie présentée permet donc, pour une (ou des) précision(s) désirée(s) sur les résultats, de déterminer puis de comparer le nombre optimal d’unités statistiques à échantillonner pour différents protocoles. La première étape de la procédure développée nécessite de recréer mathématiquement la population statistique la plus représentative possible de la population étudiée. Ensuite, les différentes combinaisons protocole d’échantillonnage / nombre d’unités statistiques sont simulées puis comparées. Cela permet d’obtenir le meilleur rapport coût-efficacité pour une étude nécessitant un échantillonnage dans un objectif d’inférence, autrement dit, de baisser son prix tout en garantissant une précision adéquate.Les objectifs de cette thèse ont été atteints : la méthode à été développée puis testée sur trois cas d’études. Le premier est la mise en place d’un suivi efficace lorsqu’il n’existe pas de données disponibles. L’exemple utilisé est celui de la mise en place du suivi du moustique tigre sur l’agglomération de Bayonne-Anglet-Biarritz. L’espèce est en début d’invasion dans cette zone et il n’existe donc quasiment pas de données de suivi. Nous avons récupéré les données de détection dans des villes méditerranéennes, les avons modélisées et avons appliqué le modèle à l’agglomération d’intérêt pour ensuite y définir un protocole de suivi optimal.Le second cas d’étude est l’optimisation d’un suivi lorsque seulement une saison de données est disponible. L’exemple est celui du suivi de la palourde dans le bassin d’Arcachon. Ce suivi est effectué tous les 2 ans depuis 2006, nous avons travaillé sur une seule année de données et prouvé qu’il était possible d’optimiser ce suivi. C’est-à-dire baisser son coût de 30% en gardant une précision assez bonne sur les résultats pour être en capacité de mettre en place des mesures de gestion adaptées. Nous avons ensuite travaillé sur toutes les données depuis 2006 pour proposer une optimisation de ce suivi pérenne dans le temps. / Developing robust, and reliable, environmental surveys can be a challenge because of the inherent variation in natural environmental systems. This variation, which creates uncertainty in the survey results, can lead to difficulties in interpretations. The objective of this thesis was to develop a general framework, adaptable to environmental surveys, to improve scientific survey-results. We have developed a method that allows the user, by defining their desired level of accuracy for the survey results, to develop an efficient sampling design with a minimal sample size.Once the sample size is known, calculating total cost of the survey becomes straightforward. We start from the definition of sampling design performance and build a method for comparison and assessment of an optimal sampling design. As a rule of thumb, the more efficient a sampling design is, the fewer statistical units are needed to achieve the desired accuracy. With less sampling effort the sampling procedure becomes more cost effective. Our method assists in identifying cost-efficient sampling procedures.In this PhD thesis a general methodology is developed, and it is assessed with three case studies. The first case study involved design of an efficient survey when no prior data are available. Here we used the example of tiger mosquito in the Bayonne-Anglet-Biarritz agglomeration (south-west France). This species has only now started invading this area and therefore there are no site-specific data available. We used data from other French Mediterranean’s cities to model the probability mosquito are present in the Bayonne-Anglet-Biarritz area of interest. We used this modelled-population to assess, compare and select an effective sampling procedure.The second case study was for survey optimization when only one season of data are available. The chosen example was from Arcachon bay’s manila clam survey in western France. This clam-monitoring has been done biennially (i.e. once every two years) since 2006. We applied our general methodology on one-year data and demonstrated that survey costs can be reduced by 30% a year with no loss of accuracy or reduction in resource management information. The third case study was based on optimization of a survey when several seasons of data are available. We used the clam surveyed but here as a multi-year dataset. We proposed a long-term spatial and temporal sampling design for monitoring the clam resource.

The advent of Social Networking Systems (SNS) has introduced new possibilities for planners to refine and extend conventional engagement and data-gathering techniques by leveraging user-contributed, spatially-referenced content freely available online. This study examines the use of SNS content as community input, complementing input gathered through traditional participatory processes such as workshops, public comment hearings, and charrettes. Four case studies of recent community planning projects in the United States are analyzed, comparing the data gathered from traditional participatory processes with available SNS content related to each project study area, to determine to what extent the inclusion of SNS data would improve the overall data- gathering efforts of these projects. Three significant findings emerge from this analysis: (i) that SNS data analysis can positively complement data gathered from traditional participatory processes, (ii) that although SNS data analysis can provide useful data to planners, it is not a direct replacement for conventional engagement techniques, and (iii) that SNS data analysis is most effective for projects in neighborhoods with a well- defined identity. The study also examines the characteristics of effective SNS data analysis integration and discusses broader implications for planning practitioners and additional research needed.

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A new methodology is proposed to perform nonlinear time domain analysis on three-dimensional reinforced concrete bridge structures subjected to spatially varying seismic ground motions. A stochastic algorithm is implemented to generate unique and correlated time history records under each bridge support to model the spatial variability effects of seismic wave components traveling in the longitudinal and transverse direction of the bridge. Three-dimensional finite element models of highway bridges with variable geometry are considered where the nonlinear response is concentrated at bidirectional plastic hinges located at the pier end zones. The ductility demand at each pier is determined from the bidirectional rotations occurring at the plastic hinges during the seismic response evaluation of the bridge models. Variability of the soil characteristics along the length of the bridge is addressed by enforcing soil response spectrum compatibility of the generated time history records and of the dynamic stiffness properties of the spring sets modeling soil rigidity at the soil-foundation interface at each support location. The results on pier ductility demand values show that their magnitude depends on the type of soil under the pier supports, the pier location and the overall length and geometry of the bridge structure. Maximum ductility demand values were found to occur in piers supported on soft soils and located around the mid span of long multi-span bridges. The results also show that pier ductility demand values in the transverse direction of the bridge can be significantly different than the values in the longitudinal direction and in some instances, the maximum value occurs in the transverse direction. Moreover, results also show that ignoring the effects of spatial variability of the seismic excitation, the pier ductility demand can be severely underestimated. Finally, results show that increasing the vertical acceleration component in the seismic wave will generate an increase in the pier axial loads, which will reduce the ductility range of the pier plastic zones. As result, even though the increase in pier ductility demand associated with the increase in the vertical acceleration component was found to be relatively small, the number piers exhibiting significant structural damage increased.

This thesis describes methods for using spectral interferometry for the complete space-time characterisation of few-cycle near-infrared femtosecond pulses and extreme ultraviolet (XUV) attosecond pulses produced via high harmonic generation (HHG). Few-cycle pulses tend to exhibit one or more of the following: (1) an octave-spanning bandwidth, (2) a highly modulated spectrum and (3) space-time coupling. These characteristics, coupled with the desire to measure them in a single-shot (to characterise shot-to-shot fluctuations) and in real-time (for online optimisation and control) causes problems for conventional characterisation techniques. The first half of this thesis describes a method, based on a spatially encoded arrangement for spectral phase interferometry for direct electric-field reconstruction (SEA-SPIDER). SEA-SPIDER is demonstrated for sub-10fs pulses with a central wavelength near 800nm, a bandwidth over 350nm, and a pulse energy of several nano-Joules. In addition, the pulses exhibit a modulated spectrum and space-time coupling. The spatially-dependent temporal intensity of the pulse is reconstructed and compared to other techniques: interferometric frequency-resolved optical gating (IFROG) and spectral phase interferometry for direct electric field reconstruction (SPIDER). SEA-SPIDER will prove useful in both femtoscience, which requires accurate knowledge of the space-time character of few-cycle pulses, and in HHG, which requires the precise knowledge of the driving pulse for seeding into simulations and controlling the generation process itself. Pulses arising from HHG are known to exhibit significant space-time coupling. The second half of this thesis describes how spectral interferometry may be performed to obtain the complete space-time nature of these fields via the use of lateral shearing interferometry. Finally, it is shown, via numerical simulations, how to extend the SPIDER technique for temporal characterisation of XUV pulses from HHG by driving the process with two spectrally-sheared driving pulses. Different experimental configurations and their applicability to different laser systems are discussed. This method recovers the space-time nature of the harmonics in a single shot, thus reducing the stability constraint currently required for photoelectron based techniques and may serve as a complimentary method for studying interactions of XUV attosecond pulses with matter.