Jurassic Karst

The “Jurassic Karst” scheme in place since 2009 aims to characterise the long-term evolution of the karst aquifers of the Jura mountains.

About 80% of the drinking water and almost all of the river water in the Jura Mountains comes from karst springs. The Jurassic Karst Observatory aims to study the links between the biogeochemical functioning of the infiltration zone and the hydrochemical response of karst systems, paying particular attention to the consequences of global warming and changes in land use.

The specific topographical context of the Jura Mountains means these processes can be studied at increasing altitudes along a climatic gradient. The plant cover and soil types vary along this gradient, thereby modulating the biogeochemical functioning of the infiltration zone of the karst hydrosystems.

Where and When

The Jurassic Karst observatory integrates 4 monitoring sites along an altitude gradient in order to get a representative picture of the karst systems of the Jura mountains:

  • Fourbanne site (Doubs valley, near Baume-les-Dames): altitude 270 m, catchment basin of 30 km2.
  • Arcier site (Doubs valley, near Besançon) : altitude 270 m, catchment basin of 100 km2.
  • Lods site (upper Loue valley): altitude 380 m, catchment basin of 35 km2.
  • Fertans site (Amancy plateau): altitude 500 m, catchment basin of 1 km2. The monitoring of this site was stopped in 2020.
  • Mouthe site (spring of the Doubs river): altitude 950 m, catchment basin of 50 km2.

Monitoring since 2009

A number of physico-chemical parameters are monitored continuously on all sites using automatic probes. This continuous monitoring is supplemented by automatic water samples at the sites of Fourbanne, Arcier and Lods (2 samples/week).

Visit the 9 observatories