Intrinsic vulnerability mapping for small mountainous karst aquifers, implementation of the new PaPRIKa method to Western Pyrenees (France)

•PaPRIKa is proposed as a tool to assess groundwater protection of small karst systems.•PaPRIKa can assess both the resource and source vulnerability.•The vulnerability of the resource was assessed for the entire catchment area.•Source-orientated mapping was attempted for the catchment area of the main capture.

The new intrinsic vulnerability mapping method PaPRIKa is proposed as a tool to assess groundwater protection of small karst systems exploited for drinking water supply purposes in the French Pyrenees. The specific characteristics of the discontinuous carbonate aquifers of mountainous areas are here considered and taken into account into the implementation of the methodology. The Orbe site from the French Western Pyrenees area is chosen as a test site because of the relatively well known structure and behavior of the aquifer system. Steep slopes, extremely developed dissolution features, thin soils and strong dipping of geological formations are the main points to be considered. PaPRIKa method appears as a tool to assess and illustrate both the resource and source vulnerability according to the site specificities provided that appropriate field observations at a relatively high density are carried out. The vulnerability of the resource was assessed for the entire catchment area, while source-orientated mapping was attempted for the catchment area of the main capture work used for drinking water supply.