MELANGE

The quantification of suspended matter concentrations and fluxes is a major challenge in order to better understand the role of coastal areas in the storage and transfer of matter to the deep ocean. These materials concern the elements of biogeochemical cycles (C, N, P, P, Si,...) but also the organic materials, nutrients and contaminants that control and influence the functioning of coastal ecosystems. These material fluxes occur mainly during intense meteorological events (floods and storms) from the catchment areas to the coastal zone where they are temporarily stored and then exported by currents and tides. However, there are very few measurements of these fluxes during intense events and are mainly derived from measurements from satellite images, buoys and other fixed anchorages. The ASTRID-MATURATION "MELANGE" project (real-time Measurement of sEdiment fLuxes in coAstal zoNe using GlidErs) is a follow-up to the ASTRID "MATUGLI" project (autonomous Measurements of coAstal TUrbidity using GLIders) during which was developed a prototype glider for autonomous turbidity measurements. Within the framework of the MELANGE project, it is planned to make this prototype more reliable with the help of an industrialist (ALSEAMAR) and an PME (CENTRALWEB) in order to produce a tool capable of measuring and transmitting measurements of current, turbidity and in fine material fluxes at various spatial (from metre to hundred kilometres) and temporal (from second to several months) scales of the coastal zone. This tool could eventually be used to monitor coastal water quality under the Water Framework Directive and the Marine Environment Strategy Framework Directive for marine parks, for example, and to monitor underwater current and visibility for military applications, but these data will also be used to feed hydrodynamic models for coastal forecasting.