WISE 2016 GroundWaterBodyHorizon_FR_20160726

GroundWaterBody means a distinct volume of groundwater (All water which is below the surface of the ground in the saturation zone and in direct contact with the ground or subsoil.) within an aquifer or aquifers (Subsurface layer or layers of rock or other geological strata of sufficient
porosity and permeability to allow either a significant flow of groundwater or the abstraction of significant quantities of groundwater)
The horizons element identifies the different horizons in the groundwaterbody

Horizon 1 is attributed to all or part of the first waterbody encountered from the surface, horizon 2 is attributed to the part of groundwaterbody under cover of a horizon 1 water body, etc ...
One waterbody may have different horizons, depending on the geographical position . In the GroundwaterBodyHorizon layer, each groundwaterbody polygon corresponds to a portion with specific horizon value.