HAL Collection UNC (Univ. de la Nouvelle Calédonie)
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Social-ecological system approach relevant for modelling the ecological niche of a mangrove gastropod at small regional scale
No full textInternational audienceThe gastropod Terebralia palustris is found in mangroves from the Indo-Pacific, where it plays important ecological roles and is fished by humans. As such, it reflects interactions occurring within the socio-ecosystem, although information regarding its regional distribution and ecological niche is uneven. The present study aimed at defining the relative importance of factors of the mangrove socio-ecological system (MSES) on the realized niche of T. palustris at the regional scale. We studied its distribution at the scale of Mayotte Island (France, Indian Ocean), including local ecological knowledge and environmental memory held by population. To this end, a survey campaign of the 29 mangroves of Mayotte allowed mapping its occurrence and correlating the spatial pattern to factors of the MSES related to three dimensions of the niche (accessibility, abiotic, and biotic) pertaining to both societal and ecological components. Questionnaire interviews revealed both past presence and current presence undetected by the survey campaign. At the scale of Mayotte, the gastropod is found on large and deep mangroves, distant from the sea by a deep central and external mangrove, where Avicennia marina is not the only mangrove tree species and the canopy is relatively opened, at the bottom of watersheds holding large urban areas. Our study showed that dealing with both ecosystemic and societal subsystems and their involvement in each dimension of the niche concept is a promising way of understanding the drivers of species distribution in anthropized system
Modeling the Conversion of Forest Land to Other Types of Occupation Due to Urban Growth in Five Forest Towns in the Congo Basin
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L'activité physique des adolescents de Nouvelle-Calédonie vivant en milieux ruraux et urbains : rôle des facteurs socio-environnementaux et association avec le statut pondéral
No full textInfographie résumant l'article scientifique suivant : Wattelez G., Frayon S., Caillaud C., Galy O. Physical Activity in Adolescents Living in Rural and Urban New Caledonia: The Role of Socioenvironmental Factors and the Association With Weight Status. Front. Public Health. 2021; 9:623685. doi: 10.3389/fpubh.2021.623685Infography related to the following scientific paper: Wattelez G., Frayon S., Caillaud C., Galy O. Physical Activity in Adolescents Living in Rural and Urban New Caledonia: The Role of Socioenvironmental Factors and the Association With Weight Status. Front. Public Health. 2021; 9:623685. doi: 10.3389/fpubh.2021.623685Infographie résumant l'article scientifique suivant : Wattelez G., Frayon S., Caillaud C., Galy O. Physical Activity in Adolescents Living in Rural and Urban New Caledonia: The Role of Socioenvironmental Factors and the Association With Weight Status. Front. Public Health. 2021; 9:623685. doi: 10.3389/fpubh.2021.62368
Associations entre statut pondéral, satisfaction corporelle, identité ethnique, et estime de soi chez les adolescents océaniens
No full textInfographie résumant l'article scientifique suivant :Frayon S., Swami V., Wattelez G., Todd J., Galy O. Associations between weight status, body satisfaction, ethnic identity and self-esteem in Oceanian adolescents. Pediatric Obesity. 2021; 16(12):e12824. doi: 10.1111/ijpo.12824Infographie related to the following scientific paper: Frayon S., Swami V., Wattelez G., Todd J., Galy O. Associations between weight status, body satisfaction, ethnic identity and self-esteem in Oceanian adolescents. Pediatric Obesity. 2021; 16(12):e12824. doi: 10.1111/ijpo.12824Infographie résumant l'article scientifique suivant :Frayon S., Swami V., Wattelez G., Todd J., Galy O. Associations between weight status, body satisfaction, ethnic identity and self-esteem in Oceanian adolescents. Pediatric Obesity. 2021; 16(12):e12824. doi: 10.1111/ijpo.1282
"Les vulnérabilités traumatiques et leurs réversibilité en contexte universitaire. Analyse ethnographique de pratiques (trans)formatives en KNC", Numéro coordonné par C. Baeza, C. Fontaine er C. Biasin
No full textInternational audienceDans une approche pédagogique « sensible », qualifier des publics apprenant.e.s de « vulnérables » appelle à un renversement d’optique face aux fragilités que le terme peut, par défaut, amplifier. Il importe donc de repenser la singularité des étudiant.e.s davantage comme des ressources didactiques qu’un obstacle à franchir. Notre analyse ethnographique s’intéresse aux pratiques (trans) formatives adoptées en contexte universitaire (post) colonial. Elles visent la prise en compte de besoins narratifs et besoins de reconnaissance symbolique de publics dits « vulnérables » parce que l’histoire les a construits en tant que tels en Kanaky Nouvelle-Calédonie. Quels dispositifs permettent la réversibilité de telles « vulnérabilités traumatiques »
Projections of extreme rainfall and floods in Mediterranean basins from an ensemble of convection-permitting models
No full textInternational audienceFloods have major impacts in the Mediterranean regions, but their evolution with climate change is unclear. This issue is related to the inadequacy of climate and hydrological models in terms of spatial and temporal resolutions to simulate flash floods over small basins. This study explores future flood scenarios of 12 Mediterranean basins using meteorological forcings from an ensemble of high-resolution convection-permitting climate models. Results indicate an overall increase in flood intensity across all basins, particularly for the most severe events, but also a strong spatial variability of the climate change signal given the geographic location and catchment characteristics. There is a good agreement between the models towards an increase of hourly rainfall extremes, but these changes are not well correlated with changes in floods, indicating that rainfall intensity alone is a poor predictor of future floods. An overall conclusion towards an increase of floods in this region is limited by the short length of the available high-resolution climate simulations. Longer time series are required to better assess the robustness of the projected changes
Coupling high resolution meteorological models with neural networks for flash flood forecasting: implementation on a Southern France basin
No full textInternational audienceFlash floods are an important hazard that particularly affects the Mediterranean region. Flood forecasting using simulation tools adapted to this context is therefore a crucial issue. In exposed regions, the difficulty of measuring and forecasting the spatial variability and intensity of rainfall, as well as the difficulty of identifying processes at the necessary time and space scales, has often led to the use of highly conceptual - or even statistical - models that make few assumptions about hydrological processes. Among these, neural networks have proven their relevance for flash flood forecasting. However, without hydrometeorological coupling, flow forecasting is often limited to the response time of the basin, i.e. a few hours in general. The purpose is to find a way of increasing this lead time, which is often too short for crisis management.A flood forecasting model for the Gardon de Mialet basin (Southern France) is being developed as part of the HydIA joint laboratory funded by the ANR (French National Research Agency) and the Synapse company, with the aim of developing a range of hydrometeorological forecasting services based on artificial intelligence approaches. The use of gridded observed data, like in a meteorological model, has enabled the neural network model implemented (Multilayer Perceptron) to reduce its sensitivity to support change.In the absence of rainfall forecasts, performance decreases with the lead time. With perfect forecasts (observed data used as future data), performance remains high for lead times up to 24h. The model has been coupled with two high resolution weather models, AROME and ARPEGE (2.5km and 10km respectively), implemented by Météo-France for short-range numerical weather prediction. The use of forecasts from these meteorological models for the 49 events in the database enables us to identify the error generated by the hydrological model and that generated by the meteorological model, in comparison with perfect forecasts. Analysis of these errors opens operational perspectives for crisis management. It also makes it possible to improve model training based on perfectible forecast data, and to correct rainfall forecasting biases to achieve higher performance
La dengue en Asie du Sud-Est. Enjeux pour un système de surveillance transnational : Thaïlande, Laos, Cambodge et Viêtnam
No full textInternational audienceDengue is a disease caused by an arbovirus transmitted by mosquito vectors of the Aedes genus, primarily Aedes aegypti and Aedes albopictus, which are widely distributed across Southeast Asia. The region’s climatic conditions favor their proliferation, while increasing urbanization provides abundant breeding sites and opportunities for human-mosquito contact. In the absence of an effective vaccine, monitoring and controlling mosquito populations remain essential strategies for combating the disease, alongside tracking the dynamics of local and regional epidemics. This requires regular monitoring of two key factors: meteorological parameters, which influence the growth and decline of vector populations, and human mobility at local, regional and transnational scales, which shape the spatio-temporal dynamics of dengue transmission. Dengue is therefore a complex pathogenic system, with a geography influenced by both local and transnational factors, requiring multi-scale intervention strategies. This chapter aims to present dengue epidemic surveillance systems in four countries (Thailand, Laos, Cambodia and Vietnam) and to outline the requirements for establishing a transnational surveillance system.La dengue est une maladie virale transmise par les moustiques vecteurs du genre Aedes largement présents dans tous les pays d’Asie du Sud-Est. On y trouve en effet des conditions climatiques favorables à leur prolifération et des taux d’urbanisation croissants qui leur procurent une infinité de lieux de ponte et d’opportunités de piqure. La lutte contre cette maladie passe par la surveillance et le contrôle des populations de moustique, ainsi que par le suivi des dynamiques des épidémies locales et régionales. Cela implique entre autres le suivi régulier de deux facteurs essentiels : les paramètres météorologiques qui impactent directement la croissance et décroissance des populations de vecteur ; les flux des populations humaine aux échelles locales, régionales et transnationales qui orientent les dynamiques spatio-temporelles des cas de dengue. La dengue est ainsi un système pathogène complexe dont la géographie dépend aussi bien de conditions locales que transnationales, nécessitant des interventions à plusieurs échelles. L’objectif de ce chapitre est de présenter les systèmes de surveillance des épidémies de dengue dans quatre pays (Thaïlande, Laos, Cambodge et Viêtnam) et de poser les conditions de la mise en place d’un système de surveillance transnational
Olive production in the 21st century will be threatened by water stress and declining solar activity
No full textInternational audienceThe production of olive oil, a cornerstone of Mediterranean diet, faces important threats from recurring droughts and the anticipated decline in cyclical solar activity. These escalating challenges cast uncertainty on the long-term sustainability of olive-growing regions. Here we draw on 8000 years of olive pollen data - closely related to flowering, fertilization and fruit production - to identify the key long-term determinants influencing olive yields. Our findings indicate that pollen production, and therefore yields, are primarily driven by photosynthesis, which is influenced not only by temperature and CO2 levels, but also by precipitation during olive phenological stages and changes in the radiation balance, rather than by variations in solar energy alone. Changes in photosynthetic activity emerge as a critical determinant of the future of the Mediterranean olive oil economy and have major implications for food security in the region
Le blocage de Tik Tok retoqué
No full textInternational audienceAlors que le juge des référés avait rejeté le recours dirigé contre le blocage temporaire du réseau social Tik Tok en Nouvelle-Calédonie après le déclenchement de la crise du 13 mai (CE, ord. réf., 23 mai 2024, n° 494320), le Conseil d’État vient de juger que la décision du Premier ministre avait porté une atteinte disproportionnée à la liberté d’expression, à la liberté de communication des idées et opinions et à la liberté d’accès à l’information (CE 1er avr. 2025, nos 494511, 494583 et 495174, Ligue des droits de l’homme, La Quadrature du net, M. C. et autres). Décryptage