Conceptual uncertainties in groundwater and porewater fluxes estimated by radon and radium mass balances

Radium isotopes and radon are routinely used as tracers to quantify groundwater porewater fluxes into coastal freshwater systems. However, uncertainties associated with the determination of tracer flux often poorly addressed neglect all potential errors conceptualization system (i.e., conceptual uncertainties). In this study, we assess magnitude some key related radium inputs supplied by a waterbody (La Palme Lagoon, France). This uncertainty assessment is through single model ensemble approach, where mass balance run multiple times variable sets assumptions approaches for parameters determined sensitivity test. particular, linked concentration, diffusive fluxes, evasion atmosphere, change inventory over time were considered. The further constrained using comparison independent methods: (1) 224Ra (2) 222Rn balances in overlying waters, (3) deficit sediments, (4) fluid-salt numerical transport model. We demonstrate that commonly major source on estimation or they need be taken account when balances. absence general framework assessing these uncertainties, study provides practical approach evaluate