Assessment of sediment and organic carbon exports into the Arctic ocean: the case of the Yenisei river basin

The export of organic carbon export by the rivers to the oceans either as particulate organic carbon (POC) or dissolved organic carbon (DOC) is very sensitive to climate change especially in permafrost affected catchments where soils are very rich in organic carbon. With global warming, organic carbon export in both forms is expected to increase in Arctic regions. It should affect contemporary biogeochemical cycles in rivers and oceans and therefore modify the whole food web. This study tries to understand complex processes involved in sediment, POC and DOC riverine transport in the Yenisei River basin and to quantify their respective fluxes at the river outlet. The SWAT (Soil and Water Assessment Tool) hydrological model is used in this study to simulate water and suspended sediment transfers in the largest Arctic river. POC and DOC export have been quantified with empirical models, adapted from literature for the study case. First, the hydrological model has been calibrated and validated at a daily time step for the 2003–2008 and the 2009–2016 periods respectively, and its output has been compared with field data for water and sediment fluxes. Based on conceptualization of transfer processes, calibration on climate and soil properties has been performed in order to correctly represent hydrology and sediment transfer in permafrost basins. Second, calibration of empirical models for DOC/POC transport have been performed by comparing their output with field data, available from 2003 to 2016. Our study reveals that SWAT is capable of correctly representing hydrology, sediment transfer, POC and DOC fluxes and their spatial distribution at a daily timescale, and outlines the links between these fluxes and permafrost features. Our simulation effort results in specific sediment, POC and DOC fluxes of 2.97 t km−2 yr−1, 0.13 t km−2 yr−1 and 1.14 t km−2 yr−1 for the period 2003–2016 which are in the range of previous estimates. About 60% of the total fluxes of sediment, DOC and POC to the Arctic Ocean are exported during the two months of the freshet. Spatial analysis show that permafrost-free areas have returned higher daily organic carbon export than permafrost affected zones, highlighting the thawing permafrost effect on carbon cycle in climate change feedback

China at Skin Level : english- and french-speaking agents of influence in China and chinese bodily difference : from the 1830s to the early 1920s

Des années 1830 aux premières années de la République chinoise, services diplomatiques occidentaux et sociétés missionnaires attendent des agents qu’ils déploient dans l’Empire des Qing qu’ils désamorcent la prétendue xénophobie chinoise pour faciliter la pénétration diplomatique, commerciale et évangélique du pays. Cette préoccupation constitue l’accès à l’intimité des populations et des autorités chinoises en enjeu crucial et fait des médecins missionnaires protestants comme des médecins français détachés auprès du Quai d’Orsay des acteurs importants des politiques d’influence diplomatiques et évangéliques en Chine. C’est à la lumière de ces dernières que cette thèse aborde les savoirs occidentaux sur la différence chinoise des corps. Le décalage entre l’absence de cohérence raciale de la Chine pour l’anthropologie raciale du XIXe siècle et l’essor, tout au long du siècle, de savoirs relatifs aux corps chinois invite en effet à étudier ces derniers, non comme une simple déclinaison de théories raciales, mais à partir même des savoirs pratiques développés sur le terrain par les diplomates, missionnaires et médecins anglophones et francophones que nous choisissons de désigner comme agents d’influence occidentaux en Chine. Parce qu’on attend d’eux qu’ils sachent interagir, négocier avec des interlocuteurs chinois, les convertir ou les soigner, il leur incombe de déterminer ce que l’écart entre corps occidentaux et chinois leur impose d’ajustements et d’apprentissages. C’est dans l’incorporation même des dispositions qu’il leur faut donc acquérir – depuis la maîtrise de l’étiquette chinoise jusqu’au savoir-faire de la pratique médicale en Chine – que sourdent les réflexions sur cet écart corporel, dont les stéréotypes relatifs aux corps chinois qui se figent progressivement au cours du siècle constituent bien souvent autant de vies posthumes. À les étudier ainsi au plus près de la pratique, on se donne les moyens de saisir ce que les savoirs sur la différence chinoise des corps au XIXe siècle doivent à une diversité de théories savantes autant qu’aux enjeux professionnels et aux ambitions sinologiques qui guident les agents d’influence sur le terrain ; à leur expérience corporelle et sensible de la Chine autant qu’aux processus de co-construction qui mettent en jeu divers types de fixeurs et de savoirs chinois.From the 1830s to the early years of the Chinese Republic, Western diplomatic services and missionary societies expected the agents they dispatched to the Qing Empire to defuse the alleged Chinese xenophobia and ease the penetration of the country. Accessing the intimacy of Chinese laymen and officials became a critical issue, and medicine a key tool of diplomatic and evangelical influence policies in China. This thesis examines Western knowledge on Chinese bodily difference in the light of these policies. Nineteenth-century racial anthropology recognised no such thing as a Chinese race, and yet knowledge regarding Chinese bodies flourished throughout the century. This thesis argues that this knowledge should not be understood as a mere offshoot of racial theories, but investigated as the result of fieldwork practices by anglophone and francophone diplomats, missionaries and doctors, thereafter labelled as Western agents of influence in China. The incorporation of the diverse skills they had to acquire in China – ranging from the mastery of etiquette to the know-hows of medical practice – played a critical part on how they conceived of the gap between Western and Chinese bodies. While these reflections drew from a variety of scholarly theories, they were equally indebted to the professional stakes and sinological ambitions that drove these agents in the field, to their bodily and sensitive experience of China, and to the processes of co-construction that brought into play a variety of Chinese knowledge and brokers

"Lire les corps. Présentation"

International audienc

"Lire les corps" numéro spécial, n° 123, Genèses

International audienc