Groundwater Vulnerability to Pollution O factor map (Overlying layers) in karstic aquifers of Catalonia according to COP

Overlying layers factor map indicates the natural protection of the groundwater surface provided by the geological layers of the unsaturated zone and the overlying soil. It is expressed as a value according to COP ranges from 1 to 15, being 0 the less degree of protection and the range of 8 - 15 the highest degree of protection.