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Title: EcH<sub>2</sub>O-iso 1.0: Water isotopes and age tracking in a process-based,distributed ecohydrological model
We introduce EcH2O-iso, a new development of the physically-based, fully-distributed ecohydrological model EcH2O where the tracking of water isotopic tracers (2H and 18O) and age has been incorporated. EcH2O-iso is evaluated at a montane, low-energy experimental catchment in eastern Scotland using 16 independent isotope time series from various landscape positions and compartments; encompassing soil water, groundwater, stream water, and plant xylem. We find a good model-observation match in most cases, despite having only calibrated the model using hydrometric data and energy fluxes. These results provide further validation of the physical basis of the model for successfully capturing catchment hydrological functioning, both in terms of the celerity in energy propagation (e.g. runoff generation under prevailing hydraulic gradients) and flow velocities of water molecules (e.g., in consistent tracer concentrations at given locations and times). We also show that the spatially-distributed formulation of EcH2O-iso provides a powerful tool for quantitatively linking water stores and fluxes with spatio-temporal patterns of isotopes ratios and water ages. Finally, our study highlights some model development and benchmarking needs, refined using isotope-based calibration, for hypothesis testing and improved simulations of catchment dynamics that is transferable beyond the catchment landscape studied here.
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Geoscientific Model Development Discussions
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1 to 38
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National Science Foundation
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