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International audience; In alpine and piedmont gravel bed Rivers, sand can be transported as bed load or as suspended load over a coarser bed. This explains why most of the monitoring tools, which have been developed for bed load or suspended load, do not adequately measure the sand frac-tion, which is mainly transported at the transition between these two modes. This difficultyin measuring the sand fraction is a real problem because sand is a major component of the total load transferred from the mountain to the sea. Some techniques have been specially designed for sand measurement; they can be effective but not always easy to deploy. That is why we propose here to test a new method, based on a submerged pump initially developed for hostile environ-ments such as drilling operations, and capable of withstanding high loads of fine sediments. The pumping tests were carried out in the Isère River during July 2019, and compared to a isokinetic flux sampler: the Delft bottle. We present the results and limitations of the method.

International audience; The Rieu Benoît is a debris-flow-prone catchment located in Valloire (Savoie, France). In 2011, a lateral landslide was detected about 600 m upstream of the fan apex where houses are present. This landslide has evolved slowly since 2011 but is likely, in case of rapid collapse, to provide up to 150,000 to 200,000 m 3 of material to the channel and generate intense debris flows thus threatening human settlements on the fan and in the Valloire ski resort. This paper presents a contribution to the definition of a protection strategy based on the principle that a catastrophic evolution of the landslide can be detected sufficiently in advance to set up an effective alert procedure. Such early warning system can be designed provided (i) the landslide is instrumented to properly detect its evolution and characterize the volumes likely to mobilize into debris flows, this is carried out using photogrammetric, seismic, and electrical techniques; (ii) the interaction between the landslide and the channel is observed and sufficiently understood, this is carried out using a time-lapse camera taking a picture every two hours and at higher frequency once a flow is detected by a geophone; (iii) subsequent debris flows are observed and characterized in terms of flow thickness and velocity, this is carried out at a monitoring station located at the fan apex and equipped with a radar flow stage sensor and three geophones; (iv) consequences on urbanized areas are evaluated a priori on the basis of scenarios, this is carried out by simulating the spreading of debris flows for different volumes and material properties. The final step consists in building alert and evacuation procedures in collaboration with local authorities.

Downy mildew caused by Plasmopara viticola is probably the most serious disease affecting grapevine (Vitis vinifera L.) and is capable of causing consistent yield losses. In organic viticulture, the only acceptable and effective means to control the disease is by applications of copper-based fungicides. However, the use of copper in agriculture is expected to be further restricted by European countries because of its critical ecotoxicological and phytotoxicological profile. Research on ways to reduce the effective amounts of copper by developing innovative formulations as well as optimization of the distribution and persistence of copper-based pesticides for downy mildew control appears to be a promising approach. The present research investigated the delivery properties of biomimetic synthetic hydroxyapatite (HA) to enhance the biological activity of Cu(II) ions. To this aim, four Cu(II) compounds were formulated with the innovative HA component and applied in an in vitro antifungal assay against Botrytis cinerea, a common grapevine pathogen suitable for in vitro activity tests, and finally in in-planta efficacy assays against P. viticola under greenhouse conditions. The in vitro results highlighted a different inhibition activity for each Cu(II) compound and indicated a different interaction between the cupric compounds and HA, potentially related to different delivery mechanisms of Cu(II) from HA. Under greenhouse conditions, further findings on the biological activity of the applied formulations were gained, especially on the efficacy of various concentrations of HA in the formulations, on the influence of dose variation of the formulation and the treatment efficiency, and persistence under rain-washing effect. The present study revealed promising findings on the formulation based on the HA particles and the soluble Cu(II) compound, which resulted in reduced disease severity and incidence in all the experimental conditions, including the lower Cu(II) dosage and the rain-washing effect. This suggests that coformulation of the three insoluble Cu(II) compounds with HA might significantly enhance the adsorption and release of Cu(II) ions by HA particles.

National audience; L'atelier mono-carte du Réseau Mesure a démarré en 2017. L'objectif est d'étudier le potentiel des cartes électroniques autonomes de type Arduino (uno, due, nano, micro,...), Raspberry pi, carte FPGA, ou autres produits de même nature, pour réaliser des opérations de mesures dans diverses applications qui sont menés dans des environnements diversifiés : agriculture, montagne, eau, forêt,...

International audience; Sediment trapping basins are key facilities in flood protection systems of mountain catchments, specifically in torrents prone to debris flows. A better understanding of the processes generating sediment trapping is required to optimize their functioning on both the risk, economic and environmental aspects. A monitoring station composed of a rain gauge, a geophone and a camera has been installed on the Claret torrent (Saint-Julien-Mont-Denis, Maurienne Vallée, Savoie, France). In addition to a classic time-lapse acquisition with one picture per day, a flood monitoring system has been implemented. Over a certain amplitude threshold, the geophone triggered camera acquisition each second. It aimed at obtaining direct observation of debris flow spreading in the retention basin of the open check dams. On June, 14th 2017, the Claret torrent experienced a 10,000 to 15,000 cubic meter debris flow. It reached the open check dam and half-filled the basin in less than 5 minutes. Samples of debris flows were taken a few days after. Grain size diameter measurements by surface counting were also performed on the boulder debris front deposit and on the debris flow body deposit. Data acquired on this debris flow was completed by past observations of debris flows in neighbouring torrents coming down from the same summit (Croix des Têtes, 2,492 m.a.s.l.). Such a direct observation of debris flow spreading in an unconfined area is rare and could be used to better understand open check dam functioning. If sufficient data can be gathered to reconstruct the hydrograph and debris flow features with reasonable uncertainties, this observation could help testing numerical model in a sort of benchmark imperfect approach. This presentation aims at showing the video and the knowledge gained on the debris flow trapping process, but also how we gathered data to reconstruct the event and start building a benchmark case study acknowledging error propagation.

[EN] Since the early 1990s, grapevine trunk diseases (GTDs) have posed threats for viticulture. Esca complex, Eutypa- and Botryosphaeria-diebacks, mostly detected in adult vineyards, are currently responsible for considerable economic losses in the main vine-growing areas of the world. Other GTDs, such as Petri- (Esca complex) and Black-foot diseases, are emerging problems in grapevine nurseries (resulting in grafting failures and/or loss of saleable plants) and in young vineyards. The impacts of GTDs in modern viticulture depend on several factors, some related to their complexity, and others linked to host plant characteristics, changes in vineyard management and to the scarcity of simple tools for their control. For these reasons control of GTDs remains difficult, also depending on knowledge transfer from research to field and vice versa. This paper outlines the main preventive and curative techniques currently applied, scientifically tested or not that have resulted from the outcomes of "Winetwork", a European Union funded project with special emphasis on the promising and innovative approaches.