A Multi-Scale Observatory of Flood and Underground Hydrodyamics in Karst Environment.

The Multi-Scale Observatory of Flood and Underground Hydrodyamics in Karst Environment (MEDYCYSS – OSU OREME) was set up to respond to problems specific to Mediterranean regions because of their particular climatic, hydrologic, and hydrogeologic environments. It includes the Lez-Mosson-Coulazou basin and corresponds to a vast karst hydrosystem of which the principal outlet is the Source du Lez, which supplies Montpellier and its surroundings.


This goal of this observatory is characterize transfer processes associated with various entities (surface and underground) of Mediterranean karst hydrosystems, and more specifically, of promoting:

  • observation and characterization at diverse scales (local and regional) of underground hydrodynamics of karst aquifers subject to the actions of climate and anthropic forcing
  • observation and understanding of the rapid hydrologic processes that take place during extreme floods in Mediterranean drainage basins that have a high karst component
  • the use of coupled hydrodynamic/hydrochemical monitoring to observe and determine the risk of groundwater contamination.

First measurements date back to 1950

Long-term monitoring conducted by the observatory includes the following:

  • Monitoring of physical, hydrochemical, isotopic, and natural fluorescence parameters at the Fontaine de Vaucluse spring and at others springs located within Fontaine de Vaucluse recharge area
  • Hydrodynamic monitoring in karst cavities and boreholes (saturated and unsaturated zones

Hydrometric monitoring of the spring is done by State agencies. Records include monthly averages since 1887, daily discharges since 1967, and hourly discharges since 1994.

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