Holocene land-use evolution and associated soil erosion in the French Prealps inferred from Lake Paladru sediments and archaeological evidences

International audienceA source-to-sink multi-proxy approach has been performed within Lake Paladru (492 m a.s.l., French Prealps) catchment and a six-meter long sediment sequence retrieved from the central lacustrine basin. The combination of minerogenic signal, specific organic markers of autochthonous and allochthonous supply and archaeological data allows the reconstruction of a continuous record of past human disturbances. Over the last 10000 years, the lacustrine sedimentation was dominated by autochthonous carbonates and the watershed was mostly forest-covered. However, seven phases of higher accumulation rate, soil erosion, algal productivity and landscape disturbances have been identified and dated from 8400-7900, 6000-4800, 4500-3200, 2700-2050 cal BP as well as AD 350-850, AD 1250-1850 and after AD 1970. Before 5200 cal BP, soil erosion is interpreted as resulting from climatic deterioration phases toward cooler and wetter conditions. During the Mid-Late Holocene period, erosion fluxes and landscape disturbances are always associated with prehistorical and historical human activities and amplified by climatic oscillations. Such changes in human land-used led to increasing minerogenic supply and nutrients loading that affected lacustrine trophic levels, especially during the last 1600 years. In addition, organic and molecular markers document previously unknown human settlements around Lake Paladru during the Bronze and the Iron Ages

Addiction

The primary aim of this study was to evaluate the impact of drug consumption rooms (DCRs) in France on injection equipment-sharing, while the secondary aims focused upon their impact on access to hepatitis C virus (HCV) testing and opioid agonist treatment (OAT). The COhort to identify Structural and INdividual factors associated with drug USe (COSINUS cohort) was a 12-month longitudinal study of 665 people who inject drugs (PWID), conducted in Bordeaux, Marseille, Paris and Strasbourg. We used data from face-to-face interviews at enrolment and at 6-month and 12-month visits. The participants were recruited in harm reduction programmes in Bordeaux and Marseille and in DCRs in Strasbourg and Paris. Participants were aged more than 18 years, French-speaking and had injected substances the month before enrolment. We measured the impact of DCR exposure on injection equipment sharing, HCV testing and the use of medications for opioid use disorder, after adjustment for significant correlates. We used a two-step Heckman mixed-effects probit model, which allowed us to take into account the correlation of repeated measures and to control for potential bias due to non-randomization between the two groups (DCR-exposed versus DCR-unexposed participants). The difference of declared injection equipment sharing between PWID exposed to DCRs versus non-exposed was 10% (1% for those exposed versus 11% for those non-exposed, marginal effect = -0.10; 95% confidence interval = -0.18, -0.03); there was no impact of DCRs on HCV testing and OAT. In the French context, drug consumption rooms appear to have a positive impact on at-risk practices for infectious diseases such as human immunodeficiency virus (HIV) and hepatitis C virus

Description des carottes du RCC de Donzère-Mondragon. OSR4 | Action II.3

Le présent rapport constitue le livrable correspondant à l’action II.3 de l’OSR4 2015-2017 : « Détermination de la dynamique sédimentaire spatiale et temporelle de la plaine alluviale du secteur de Donzère-Mondragon (DZM) : rapport d'exécution, traitement et analyse des carottes (ouverture, description, granulométrie). Il fait suite à une caractérisation électromagnétique de la zone de Donzère par radar géologique qui avait permis d’identifier des zones préférentielles de carottage peu profond (anciens chenaux, remplissages postérieurs au XIXème siècle, etc.)

Description des carottes du RCC de Pierre-Bénite. OSR4 | Action II.3

Le présent rapport constitue le livrable correspondant à l’action II.3 de l’OSR4 2015-2017 : « Détermination de la dynamique sédimentaire spatiale et temporelle de la plaine alluviale du secteur de Pierre-Bénite (PBN) : Rapport d'exécution, traitement et analyse des carottes (ouverture, description, granulométrie). Il fait suite à une caractérisation électromagnétique de la zone de Pierre-Bénite par radar géologique qui avait permis d’identifier des zones préférentielles de carottage peu profond (anciens chenaux, remplissages postérieurs au XIXème siècle, etc.)

Sedimentation and contamination patterns of dike systems along the Rhône River

International audienc

Los efectos de los sistemas de diques en la acumulación de sedimentos y contaminantes en la llanura aluvial del río Ródano

International audienc

Factors controlling groyne-field sedimentation and contamination along the Rhône River

International audienc

Factors controlling groyne-field sedimentation and contamination along the Rhône River

International audienc

Sedimentation and contamination patterns of dike systems along the Rhône River

International audienc

Programme OSR4 2015-2017. Action II.2 : Traitement et analyse des radargrammes – Pierre-Bénite

Les phases d’acquisition géophysique (radar géologique – GPR) sur le Rhône court-circuité de Pierre-Bénite se sont déroulées les 17, 18, 22, 23 et 24 novembre 2016 et 10 et 11 janvier 2017. En parallèle de l’équipe d’Hervé Piégay (sondage à la perche), cette campagne de terrain a permis l’acquisition de 67 profils au radar géologique (GPR) sur 34 sites, présentant une longueur totale de 9,93 kilomètres.Ces acquisitions géophysiques sont présentées, traitées et interprétées. Aucun profil de tomographie électrique n’a été effectué sur ce RCC.Après concertation avec l’équipe EVS de l’ENS de Lyon (Hervé Piégay et Alvaro Tena), les résultats géophysiques ont permis de positionner et de prélever 5 carottes. Les descriptions et les paramètres physiques (granulométrie) seront présentés dans un prochain livrable