Significance A record of lake sediment spanning approximately 100 years allowed us to reconstruct the long-term succession of herbicide, fungicide, and insecticide treatments in a vineyard catchment in France. This record of pesticide deposition is consistent with the historical onset and banning of these chemical substances by French and European environmental agencies. We also present evidence of the effects of postemergence herbicides, such as glyphosate, on soil erosion and evidence of the release of banned remnant pesticides, such as dichlorodiphenyltrichloroethane (DDT), that are stored in vineyard soil back into the environment. These results indicate that the sink–source dynamics of pesticides, which are crucial in ecotoxicological risk assessment, should take into account the effects of a changing environment on pesticide storage.

A high-resolution sedimentological study of Lake Bourget was conducted to reconstruct the flood frequency and intensity (or magnitude) in the area over the last 350 years. Particular emphasis was placed on investigating the spatio-temporal distribution of flood deposits in this large lake basin. The thicknesses of deposits resulting from 30 flood events of the Rho ˆne River were collected over a set of 24 short sediment cores. Deposit thicknesses were compared with instrumental data for the Rho ˆne River discharge for the period from 1853 to 2010. The results show that flood frequency and intensity cannot be reliably reconstructed from a single core because of the inhomogeneous flood-deposit geometry in such a large lake. From all documented flood-deposit thicknesses, volumes of sediment brought into the lake during each flood event were computed through a Kriging procedure and compared with the historical instrumental data. The results show, in this study, that reconstructed sediment volumes are well correlated to maximal flood discharges. This significant correlation suggests that the increase of embankment and dam settlements on the Rho ˆne River during the last 150 years has not significantly affected the transport of the smallest sediment fraction during major flood J.

International audienceThis article provides an overview of the various digital tools we have used and developed to study and promote a range of karst geosites. Our work focused on the very high heritage value endokarst sites (caves or karst networks) in France's Ardèche département (Chauvet Cave, Aven d'Orgnac) and Chartreuse (Granier cave network), Vercors (Choranche Caves) and Bauges (Prérouge Cave) Regional Parks. These tools were developed using innovative, high-tech digital monitoring and 3D modelling technologies and combined laser scanners, digital cameras and sensors with specialised software. The resulting tools are now being used in the management and promotion of these sites, which are important territorial and heritage resources in areas where geotourism is increasing and being integrated into local planning strategies