A Fully Coupled Numerical Solution of Water, Vapor, Heat, and Water Stable Isotope Transport in Soil

Water Resources Research, Journal Year: 2025, Volume and Issue: 61(1)

Published: Jan. 1, 2025

Abstract Modeling water stable isotope transport in soil is crucial to sharpen our understanding of cycles terrestrial ecosystems. Although several models for have been developed, many rely on a semi‐coupled numerical approach, solving only after obtaining solutions from and heat equations. However, this approach may increase instability errors model. Here, we developed an algorithm that solves one‐dimensional water, heat, equations with fully coupled method (MOIST). Our results showed MOIST more under various spatial temporal discretization than has good agreement semi‐analytical transport. We also validated long‐term measurements lysimeter study three scenarios hydraulic parameters calibrated by HYDRUS‐1D the first two last scenario. In scenario 1, overall NSE , KGE MAE simulated δ 18 O 0.47, 0.58, 0.92‰, respectively, compared 0.31, 0.60, 1.00‰ HYDRUS‐1D; 2, these indices were 0.33, 0.52, 1.04‰, 0.19, 1.15‰ 3, exhibited highest (0.48) (0.76), smallest (0.90) among all scenarios. These findings indicate better performance simulating flow simplified ecosystems HYDRUS‐1D, suggesting great potential furthering understandings ecohydrological processes

Language: Английский

A Continuous Semi‐nonparametric Isotope‐Based Mixing Model for Multimodal Water Uptake Patterns

Ecohydrology, Journal Year: 2025, Volume and Issue: 18(1)

Published: Jan. 1, 2025

ABSTRACT Isotope mixing models have become increasingly prevalent in the partitioning of root water uptake. However, many fail to incorporate site physical information a physically meaningful manner, whereas others adopt discrete approaches segmenting soil profile rather than continuous that aptly treat as continuum properties and conditions. Here, we present novel ‘multimodal physically‐based uptake isotope estimation’ model (Multi‐PRIME). The utilizes flexible, multimodal probability density function conjunction with water‐stable isotopes additional information, combined process‐based linear framework. To evaluate approach, estimates from boreal forest Pinus banksiana trees were compared those PRIME MixSIAR approaches. yielded comparable results; however, because highly flexible nature its semi‐nonparametric function, Multi‐PRIME reduced bias uncertainty associated segmentation specification parametric functions initial parameter values model. Furthermore, provided superior ability describe patterns cases multiple potential source regions In addition, due nature, surpassed discrete, empirically‐based both accuracy certainty. These findings illustrate benefits adopting modelling framework semi‐nonparametric, thereby providing an improvement our confidently estimate apportionment.

Language: Английский

Relationship of vegetation stand age to soil water dynamics and use in artificial shrublands and grasslands in a semiarid region

Agricultural Water Management, Journal Year: 2025, Volume and Issue: 313, P. 109487 - 109487

Published: April 14, 2025

Language: Английский