Tritium/³He measurements as calibration tools in groundwater transport modelling

The distribution of ³H and its decay product ³He in aquifers can be utilized to calibrate groundwater flow and transport models, either by using the two isotopes as separate tracers, or by using the ³H/³He age. A variety of modelling approaches has been applied to ³H/³He data sets in hydrogeological settings ranging from simple homogeneous sands to fractured bedrock systems. These studies indicate that tritium concentrations alone, as well as ³H/³He data provide powerful calibration targets for groundwater flow and transport models. ³H/³He data are also sensitive to longitudinal and transversal dispersion and to large-scale mixing and can be used to quantify these processes.