Dissolved gases in groundwater and groundwater dating methods: how useful for hydrogeological modeling? – foreword to the special issue

One of the major challenges in hydrogeology is the basic spatial lack of continuous data as this is restricted to available boreholes. Basic information is provided by the measurements of physical parameters (e.g. porosity and permeability) at the well-scale. Information related to a larger part of the aquifer are provided for example, by continuous measurement of piezometric levels or spring flow. Temporal information is extremely powerful in order to characterize aquifer functioning globally. Groundwater dating has thus been developed in order to provide time-constraints in aquifer studies.