عنوان مجله
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Journal of Advances in Modeling Earth Systems
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چکیده
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Modeling of the land surface water-, energy-, and carbon balance provides insight into the
behavior of the Earth System, under current and future conditions. Currently, there exists a substantial
variability between model outputs, for a range of model types, whereby differences between model input
parameters could be an important reason. For large-scale land surface, hydrological, and crop models,
soil hydraulic properties (SHP) are required as inputs, which are estimated from pedotransfer functions
(PTFs). To analyze the functional sensitivity of widely used PTFs, the water fluxes for different scenarios
using HYDRUS-1D were simulated and predictions compared. The results showed that using different
PTFs causes substantial variability in predicted fluxes. In addition, an in-depth analysis of the soil SHPs
and derived soil characteristics was performed to analyze why the SHPs estimated from the different PTFs
cause the model to behave differently.
The results obtained provide guidelines for the selection of PTFs in large scale models. The model
performance in terms of numerical stability, time-integrated behavior of cumulative fluxes, as well as
instantaneous fluxes was evaluated, in order to compare the suitability of the PTFs. Based on this, the
Rosetta, Wösten, and Tóth PTF seem to be the most robust PTFs for the Mualem van Genuchten SHPs
and the PTF of Cosby for the Brooks Corey functions. Based on our findings, we strongly recommend to
harmonize the PTFs used in model inter-comparison studies to avoid artifacts originating from the choice
of PTF rather from different model structures.
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