The impact of evaporation fractionation on the inverse estimation of soil hydraulic and isotope transport parameters

Choosing a suitable process-oriented eco-hydrological model is essential for obtaining reliable simulations of hydrological processes. Determining soil hydraulic and solute transport parameters another fundamental prerequisite. Research discussing the impact considering evaporation fractionation on parameter estimation practical applications isotope models limited. In this study, we analyzed results two datasets humid arid conditions using in HYDRUS-1D, which either did or not consider fractionation. The global sensitivity analysis Morris Sobol’ methods Particle Swarm Optimization algorithm highlight significant inverse modeling. Kling-Gupta efficiency (KGE) index data can increase by 0.09 1.49 datasets, respectively, when selecting scenarios. Differences estimated propagate into stable tracing: i) assessment root water uptake (RWU) drainage travel times (i.e., time elapsed between entering profile as precipitation leaving it transpiration drainage) lysimeter (humid conditions) ii) controlled experimental column (arid conditions). peak displacement method with optimized longitudinal dispersivity provides much lower than those obtained particle tracking HYDRUS-1D. Considering Craig-Gordon (CG) Gonfiantini likely to result estimates older ages RWU no scenario. mass balance that uses isotopic composition simulated HYDRUS-1D while CG models, measured flux, comparable direct laboratory measurements. contrast, scenario reasonably only method. use compositions may large biases zone where more extensive areas.