Soil-Litter-Iso: A one-dimensional model for coupled transport of heat, water and stable isotopes in soil with a litter layer and root extraction
Soil-Litter-Iso: A one-dimensional model for coupled transport of heat, water and stable isotopes in soil with a litter layer and root extraction
复制标题
DOI：
10.1016/j.jhydrol.2010.05.029
复制
发表时间：
2010-07-15
影响因子：
6.4
通讯作者：
Cuntz, Matthias
中科院分区：
文献类型：
--
作者：
Haverd, Vanessa;Cuntz, Matthias
我们提出了一个新的同位素启用水文计划，“土壤凋落物ISO”，适合作为一个同位素启用陆面模型的一部分。土壤-枯落物-Iso模型是一个模拟土壤和枯落物中热、水和稳定同位素（HDO和（H2O）-O-18）耦合运移的一维模型。它在区域范围内的使用是足够有效的，但包括耦合的热和水的传输，使总的水分通量分解成液体和蒸汽成分的复杂性。数值实现基于Ross对理查兹方程的快速解（Ross，2003）。这一点，结合显式的解决方案的能量和水分方程在土壤/空气界面，允许同位素计算厚土层和大的时间步长进行，从而显着提高计算效率相比，现有的同位素启用类似的复杂性土壤模型。我们证明了该模型的数值精度进行了一系列既定的测试情况下，并比较预测的稳态同位素浓度分布与相应的分析解决方案。我们还演示了该模型的操作在一个陆面模型进行模拟的森林通量在澳大利亚东南部的Tumbarumba网站。这些模拟表明，总蒸散量（ET）通量，其组件和它们的同位素签名是非常敏感的包括凋落物，该模型是一个有用的工具，用于评估时的ET组件的同位素签名是足够不同的通量分区是有用的。皇冠版权所有（C）2010由爱思唯尔B. V.出版保留所有权利。
We present a new isotopically enabled hydrologic scheme, "Soil-Litter-Iso", suitable for use as part of an isotopically enabled land surface model. Soil-Litter-Iso is a one-dimensional model for coupled transport of heat, water and stable isotopes (HDO and (H2O)-O-18) in soil and litter. It is sufficiently efficient for use at regional scale, yet includes the complexity of coupled heat and water transport enabling decomposition of the total moisture flux into liquid and vapour components. The numerical implementation is based on Ross' fast solution to the Richards equation (Ross, 2003). This, combined with the explicit solution of the energy and moisture equations at the soil/air interface, permit the isotopic calculations to be performed with thick soil layers and large times steps, resulting in significantly improved computational efficiency compared with existing isotopically-enabled soil models of similar complexity. We demonstrate the model's numerical accuracy by conducting a series of established test-cases and comparing predictions of steady-state isotopic concentration profiles with corresponding analytical solutions. We also demonstrate the model's operation within a land surface model by performing simulations for the forested flux site at Tumbarumba in south-eastern Australia. These simulations show that the total evapotranspiration (ET) flux, its components and their isotopic signatures are very sensitive to the inclusion of litter, and that the model is a useful tool for assessing when the isotopic signatures of the ET components are sufficiently distinct to be useful for flux partitioning. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.