Members of Géosciences Rennes are involved in several observatories:

National Observation Service H+ (national network of hydrogeological sites)

The National Observation Service H+ is the national network of observatories in hydrogeology, attached to the OZCAR research infrastructure. It includes 5 highly instrumented sites (Ploemeur, Poitiers, LSBB, Larzac, Auverwatch) for the experimentation and long-term monitoring of underground dynamics as well as an associated team for hydro-geophysical imaging (METIS). The evolution of water quantity and quality in these observatories is followed by the measurement of water levels in the groundwater and its physical, chemical and biological properties. For this purpose, in situ sensors measure certain parameters at high frequency and water samples are taken for further laboratory analyses.
In addition, geophysical signals are also measured, from dedicated probes, and allow a visualization of the evolution of hydrogeological systems from the scale of the plot to that of the watershed. Beyond the long-term monitoring of environmental variables, these observatories are also at the heart of the research and training issues addressed by Géosciences Rennes. They serve as pilot sites for the development of innovative instruments, or to test scientific hypotheses of transport in underground environments and modeling tools. Finally, each year, field placements are organized at these sites to train students from the bachelor’s degree to the master’s degree in instrumentation tools specific to hydrogeology and issues related to the management and preservation of water resources.




ORE AgrHys: Response time in agro-hydrosystems

The central issue of the AgrHys environmental research observatory is the response times of hydrogeochemical flows to forcings (climatic, agricultural and landscape) within agro-hydrosystems. These agro-hydrosystems, for hydrosystems (or watersheds) under the influence of agricultural activity are subjected to 2 types of forcings. First, the agricultural activity of the territory that induces changes in spatial structures and changes in inflows, whether water (irrigation), or minerals and organo-minerals (fertilizers, biocides, etc.). The second type of forcing is climatic and presents 2 aspects with strong short-term variability and long-term evolutions, natural or not, within the framework of global changes.


RENAG (permanent national GNSS network)

The national scientific community working with GNSS tools has gathered into th national RESIF-RENAG network that is integrated into the European EPOS research infrastructure. The aim of RENAG is to provide long-term geodesic observations of deformations affecting the Earth’s surface, generated by several processes.

Geosciences Rennes manages a GPS station located in Ploemeur (56) on the ORE H+ site and daily provides raw GNSS data to the network, data acquired every 30 seconds and downloadable free of charge on the RENAG website and on the European EPOS infrastructure. This station has qualified the hydromechanical properties of the confined aquifer of Ploemeur and makes it possible to densify the network of stations towards the west, necessary for the establishment of the deformation field of the European plate.