Abstract
The National Karst Observation Service: for a long-term monitoring of karst aquifers in the face of new climatic extremes. Karsts constitute heterogeneous aquifers, the result of the dissolution of carbonate rocks. These aquifers are now strategic water resources for different uses. At the same time, they are very sensitive to anthropogenic pressures and ongoing climate change. To answer to this societal concern, the community of karst hydrogeologists proposed to the INSU-CNRS the establishment of a national service for the observation of karstic systems (SNO KARST). Bringing together researchers and teacher-researchers, thisstructure now makes it possible to provide the community with a database including, in particular, temporal monitoring in terms of the quality and quantity of water from several French karstic systems. In addition, the SNO KARST is now a place for scientific exchanges on the topics of measurement and calibration protocols, natural or artificial tracing, signal analysis and processing, hydrological and physicochemical signatures and finally rainfalllevel-discharge modelling. The SNO KARST is also a privileged training place for master and doctoral students. Thus, since 2012, the SNO KARST system has played a structuring role for the research community and the teams that compose it now constitute a dynamic network in terms of scientific exchanges.