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Contribution à la prise en compte des services écosystémiques dans l'évaluation intégrée des solutions fondées sur la nature en milieu urbain
No full textThe urgency of the fight against climate change and the collapse of biodiversity no longer needs to be demonstrated. Nature-based solutions (NBS) and the ecosystem services they provide have been identified as important levers of action in this joint struggle. Urban living conditions, which affect the majority of humankind, increase this challenge. In this context, assessing the impacts of NBS is vital. However, we still lack an evaluation method that considers both the positive impacts of NBS (provided services) and the negative impacts (environmental costs of NBS implementation). To fill this gap, the CSTB has been developing an integrated assessment method for several years, the HIBOU 2030 method, based on life cycle assessment (LCA) and aimed at an objective evaluation of NBS and the ecosystem services they provide. This thesis is part of the HIBOU 2030 method and aims to contribute to the development of this integrated method for evaluating NBS, focusing on models for characterizing the ecosystem services of stormwater management and biodiversity support, at the development scale of a project, and using LCA to assess the environmental costs of NBS. Three NBS are considered: green roofs, urban trees and vegetated permeable pavements. The main contributions of the thesis are: - The development of an integrated water balance model at the project scale that considers different surface typologies, including the three NBS, and that enables the calculation of different stormwater management indicators (e.g. runoff, retention, etc.); - The development of a model for the biodiversity support service, that enables the calculation of a functional diversity indicator, the FAD (Functional Attribute Diversity), in an urban context; - The construction of LCA impact sheets for urban trees and vegetated permeable pavements. These methodological developments were first applied to different types of surfaces (e.g. green roofs, vegetated permeable pavements, trees in pits or boxes, permeable surfaces with bare soil, short vegetation or trees, impermeable surfaces with or without trees, etc.) and then to five scenarios of a case study (the ensemble formed by the Bienvenue site and the ENPC, in Champs-sur-Marne, in the French Île-de-France region). The results of the case study demonstrate the crucial importance of a multi-criteria, integrated approach, addressing the various aspects assessed (LCA, stormwater management and biodiversity support), to enable effective decision-making. The most advantageous scenario varies greatly according to the objective sought. The work carried out is then discussed, and the main prospects are identified: improvement of the models, their validation and the databases used, operationalization and automation of the method, and consideration of the interactions between the different aspects considered (e.g. stormwater management and biodiversity support).L'urgence de la lutte contre le changement climatique et l'effondrement de la biodiversité ne sont plus à démontrer. Les solutions fondées sur la nature (SFN) et les services écosystémiques qu'elles fournissent sont identifiés comme des leviers d'action importants dans cette lutte conjointe. Les conditions de vie urbaines, concernant la majorité de l'humanité, accroissent cet enjeu. Dans ce contexte, l'évaluation des impacts des SFN est capitale. Cependant, il manque encore d'une méthode d'évaluation considérant à la fois les impacts positifs des SFN (services rendus) et les impacts négatifs (coûts environnementaux de la mise en place des SFN). Pour répondre à ce manque, le CSTB développe depuis plusieurs années une méthode d'évaluation intégrée, la méthode HIBOU 2030, basée sur l'analyse de cycle de vie (ACV) et visant une évaluation objective des SFN et des services écosystémiques qu'elles fournissent. La thèse se place dans le cadre de la méthode HIBOU 2030 et a ainsi pour objectif de contribuer au développement de cette méthode intégrée d'évaluation des SFN, en se concentrant sur les modèles pour caractériser les services écosystémiques de gestion des eaux pluviales (GEP) et d'accueil de la biodiversité, à l'échelle d'un projet d'aménagement, et en s'appuyant sur l'ACV pour l'évaluation des coûts environnementaux des SFN. Trois SFN sont prises en compte : les toitures végétalisées, les arbres urbains et les sols drainants végétalisés. Les apports principaux de la thèse sont : - Le développement d'un modèle pour la réalisation d'un bilan hydrique intégré à l'échelle du projet incluant différentes typologies de surfaces dont les trois SFN et permettant le calcul de différents indicateurs de GEP (ex : ruissellement, rétention, etc.) ; - Le développement d'un modèle pour le service d'accueil de la biodiversité permettant le calcul d'un indicateur de diversité fonctionnelle, le FAD (Functional Attribute Diversity), dans le contexte urbain ; - La construction de fiches d'impacts ACV pour les arbres urbains et les sols drainants végétalisés. Ces développements méthodologiques ont d'abord été appliqués aux différents types de surfaces (ex : toitures végétalisées, sols drainants végétalisés, arbres en fosses ou en bacs, surfaces perméables avec sol nu, végétation basse ou arbres, surfaces imperméables avec ou sans arbres, etc.) puis sur cinq scénarios d'un cas d'étude (ensemble formé par le site Bienvenue et l'ENPC, à Champs-sur-Marne, Île-de-France). Les résultats du cas d'étude montrent l'importance cruciale d'une approche multicritère et intégrée, permettant d'aborder les différents aspects évalués (ACV, GEP et biodiversité), pour permettre une prise de décisions efficace. Le scénario le plus avantageux variant grandement en fonction de l'objectif recherché. Le travail effectué est ensuite discuté et les principales perspectives sont identifiées : amélioration des modèles, de leur validation et des bases de données utilisées, opérationnalisation et automatisation de la méthode et prise en compte des interactions entre les différents aspects considérés (ex : GEP et biodiversité)
L'éclairage favorable à la santé : un levier pour la qualité des environnements intérieurs
No full textNational audienceLight is an important dimension of the quality of indoor environments. This presentation reminds us that exposure to a natural cycle of light and darkness is the main regulatory agent of the biological circadian clock. The implications for the design of daylighting and artificial lighting of indoor environments are described. In addition to lighting, night-time darkness must be achieved in sleeping rooms by means of shutters and with sufficient blackout performance certified by quantitative indicators.Poor light quality impairs color perception, which is a common problem with LED lighting. In addition, LEDs are associated with rapid temporal light modulation resulting in strobe effects and phantom array effects that are harmful to vision. In people who are more sensitive to light, these effects are associated with headaches and visual fatigue with exposure durations of several hours.Temporal light modulation limits for lamps and luminaires are required by European regulations. Unfortunately, the user cannot trust the values declared in the EPREL European Register of Light Sources. Indeed, the analysis of the 500,000+ declarations of temporal modulation indices (as of May 2025) indicates a rate of false or non-compliant values of around 50%.La lumière est une dimension importante de la qualité des environnements intérieurs. Cet exposé rappelle que l'exposition à l'alternance lumière-obscurité est le principal agent de régulation de l'horloge biologique circadienne. Les implications pour la conception de l'éclairage naturel et l'éclairage artificiel des environnements intérieurs sont décrites. En complément avec l'éclairage, l'obscurité nocturne doit être atteinte dans les pièces de sommeil, par l'intermédiaires de volets et de fermetures ayant des performances d'occultation suffisantes, sur la base de d'indicateurs quantitatifs.Une lumière de mauvaise qualité nuit à la perception des couleurs, ce qui constitue un problème récurrent avec l'éclairage à LED. De plus, les LED sont associées à de la modulation temporelle rapide se traduisant par des effets stroboscopiques et des effets de réseaux fantômes néfastes pour la vision. Chez les personnes plus sensibles à la lumière, ces effets sont associés à des maux de têtes et de la fatigue visuelle lorsque les durées d'exposition sont de plusieurs heures.Des limites de modulation temporelle de la lumière émise par les lampes et des luminaires sont exigées par la réglementation européenne. Malheureusement, l'usager ne peut pas faire confiance aux valeurs déclarées dans le registre européen EPREL des sources de lumières. En effet, l'analyse des 500 000+déclarations des indices de modulation temporelle (en date de mai 2025) indique un taux de valeurs fausses ou non-conformes de l'ordre de 50%
Instrumentation and experimental hygrothermal investigations of a raw compressed earth brick house in Sense-City equipment: From material to building scale
No full textInternational audienc
Interactions between vibroacoustic discomfort and visual stimuli: Comparison of real, 3D and 360 environments
No full textInternational audienceThe building industry and the design of interior environments are increasingly focusing on the user experience, incorporating sensory analysis to reconsider how office environments can be optimized. New immersive technologies offer significant opportunities for sensory science, enhancing our understanding of human perception and enabling the collection of multi-sensory data under controlled laboratory conditions. While the potential of Virtual Reality (VR) for these types of studies is well recognized, certain limitations still need to be addressed, including the lack of standardized research practices and the challenge of ensuring the simulated environment closely mirrors the real world. In this study, we compare 360°and 3D formats, to real-life settings in order to determine which format offers greater ecological validity for visual perception and immersion. Additionally, we examine the effects of vibroacoustic stimuli with different levels of intensity on perception and cognition of 30 participants. Subjective, physiological and cognitive data was collected throughout the test to tackle the participant's experience. This preliminary study introduces an immersive methodology that leverages advanced techniques to gain deeper insights into multisensory user experience in VR, marking a significant step forward in the optimization of VR for building evaluation
Charte de mutualisation et ouverture des données du projet Flex-Mediation
No full textThe charter applies to all researchers contributing to or supporting the research activities of the Flex-Mediation project, and participants undertake to respect the principles set out in the charter. The charter sets out a framework to facilitate collaborative research, the sharing of resources between team members (documents, raw data, etc.) and opening up research data.La charte concerne l’ensemble des chercheur.es contribuant à l’activité de recherche ou y apportant un appui dans le cadre du projet Flex-Mediation. Les participant.es s’engagent à respecter les principes énoncés dans la charte. Cette dernière fixe un cadre pour faciliter la recherche en collectif, la mutualisation des ressources (documents, données brutes, etc.) et l'ouverture des données
La contamination en microplastiques des environnements intérieurs. De la caractérisation à l'évaluation et la prévention des risques sanitaires : comment susciter des approches interdisciplinaires ?
No full textInternational audienc
Specifying Luminaire Cutoff in Light Pollution Regulations
No full textInternational audienceThis paper examines different approaches used to specify the cutoff, or shielding, properties of luminaires in light pollution regulations, with a focus on the G* classification defined in the European road lighting standard, and the CIE flux code FC3, used in the French regulation. To compare the G* and FC3 rating schemes, a simple parametric model is introduced to generate typical luminous intensity distributions used in road lighting. In addition, these rating schemes are applied to a dataset of 145 measured luminous intensity distributions of outdoor luminaires with different characteristics. The results show that the G* classification yields more robust ratings than requirements based on FC3. However, neither FC3 nor G* can correctly predict the cutoff angle of the luminous intensity distributions, a parameter linked to the visibility of a luminaire at long distance
Measuring the temporal contrast sensitivity function of the phantom array effect
No full textInternational audienceThe phantom array effect (PAE) has been widely investigated, but data are still insufficiently consistent to accurately predict the visibility of the PAE. One of the most critical steps towards a visibility measure is the temporal contrast threshold/sensitivity function. To determine this function, we experimentally measured the visibility threshold of the PAE at various frequencies. Participants were instructed to make 54.5° saccades in the dark across a thin light source, subtending a visual angle of 0.2° (horizontally) × 10° (vertically), with a luminance of 50 cd·m-2. Their task was to indicate in which of two sequentially presented stimuli they observed the PAE, where one stimulus was the reference driven with a direct current and one was the test stimulus, sinusoidally modulated over time. The QUEST+ method was used to change the modulation depth in the test stimulus. The results revealed a bandpass-shaped sensitivity curve of the PAE, with a peak at about 600 Hz. About 70% of the 22 participants had a peak sensitivity between a modulation depth of 0.04 and 0.13, and 65% of the 22 participants had a peak frequency between 460 Hz and 700 Hz
SPARSE SURFACE PRESSURE-BASED RECONSTRUCTION OF THE FLOW AROUND A THICK AIRFOIL OVER A RANGE OF ANGLES OF ATTACK
No full textInternational audienceWe present an efficient neural-based approach to estimate the instantaneous flow field around an airfoil from limited surface pressure measurements. The model, denoted SNN-POD, relies on two independent shallow neural networks to predict the instantaneous flow over a wide range of angles of attack [10°,20°]. At all angles the global model correctly recovers the average characteristics of the flow from single-time sensor data, thus allowing combination with local, angle-dependent models. The method is applied to 2D URANS simulations of a thick airfoil at a Reynolds number of Re=4.5e6. The training set consists of snapshots obtained from a coarse sampling (1-2°) of the angle of attack range. A variance-based criterion is used to determine the number and positions of sensors. Tests are carried out for unseen snapshots at angles of attack within the set (sampled angles) as well as outside the set (interpolated angles). The maximum MSE error of attack for sampled and interpolated angles is respectively 2.9% and 6.6%. This makes it possible to develop adaptive strategies to improve the estimation if necessary
Dataset of hygrothermal and energy measurements for a raw compressed earth brick house of Sense-City equipment during different seasons
No full textInternational audienceA non-insulated raw compressed earth brick test house was built and deeply instrumented in Sense-City equipment at Champs sur Marne, France. A wide variety of sensors were deployed in the room, inside the walls and outside to monitor the hygrothermal behaviour, the thermal comfort and the heating energy consumption. The measurement campaigns were performed over several weeks during winter, spring and summer seasons in 2024. The test house was unoccupied and exposed to natural weather conditions. During winter tests, different heating scenarios were considered. The provided dataset of sensor outputs can be useful for a better understanding of earthen construction and for the experimental validation of building physics models at both the wall and building scales