Karst : a complex hydrogeologic entity

Karst is a complex hydrogeologic entity whose study requires specific and original models and approaches. The goal of SNO KARST is to bring out scientific questions and advances, specifically in terms of hydrogeochemical flux modeling at karst hydrosystem outlets and the links between global changes and the physico-chemical composition of water at the interface between hydrologic and hydrogeologic compartments. Particular attention is focused on the data-model link so as to understand better the physics and chemistry of the medium and to enhance modeling capacity to reproduce variations of flux and matter. We also point out that carbonate rocks that host karst systems are materials eminently “susceptible” to erosion and weathering and that these processes are themselves highly dependent on by expected modifications of climate, and of the hydrologic and rainfall regime. Because of these factors, karst is even more vulnerable over short time scales, which is a characteristic that is generally less meaningful in deeper non-karst hydrosystems or those that have slower hydric dynamics. The aspect of material transfer and participation in major biogeochemical cycles is also a primary preoccupation of this SNO, especially because karst systems are more vulnerable to modifications of conditions at surface boundaries.


A suitable place to merge the powers of observation and current research

SNO KARST is a suitable place to merge the powers of observation and current research on karst aquifers to compare, organize, and standardize approaches (tools, methods, concepts). Here team members work to develop tools to characterize and model water resource evolution (qualitative, quantitative) in response to forcing of short, medium, and long wavelength, within different physiographic, geologic, and climatic contexts. We hope to move toward a “synthetic” approach at the scale of large karst typologies, from characterizing their structure and operation to hydrodynamic and hydrogeochemical modeling of transfers. To accomplish this, it is necessary to perpetuate the temporal surveillance of various natural laboratories.


Challenges

SNO KARST and Research Infrastructures

SNO KARST is a national network of observatories created in 2014 by the National Institute for Earth Sciences and Astronomy (INSU) of the French National Research Council (CNRS). This network belongs to the national distributed research infrastructure (Critical Zone Observatories: Research and Application) that associates most of the French observation sites dedicated to the observation and monitoring of the critical zone and actively contributes to a pan-European infrastructure integrating Long-Term Ecosystem Research and Critical Zone and socio-ecological research observatories.