Heat and water transport in soils and across the soil‐atmosphere interface: 1. Theory and different model concepts
Heat and water transport in soils and across the soil‐atmosphere interface: 1. Theory and different model concepts
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DOI：
10.1002/2016wr019982
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发表时间：
2017-02
影响因子：
5.4
通讯作者：
J. Vanderborght;T. Fetzer;K. Mosthaf;K. Smits;R. Helmig
中科院分区：
文献类型：
--
作者：
J. Vanderborght;T. Fetzer;K. Mosthaf;K. Smits;R. Helmig
蒸发是土壤水分平衡的重要组成部分。它是由水在多孔介质中的流动和传输过程，耦合热通量和自由空气流。这项工作提供了一个全面的审查模型的概念在不同的研究领域来描述蒸发。概念范围从非等温两相流、多孔介质中与单相流耦合的双组分输运、自由空气流中的双组分输运到多孔介质中的等温液态水流，其上边界条件由可用能量和向自由空气流的转移受限时的潜在蒸发通量定义，或由土壤水可用性受限时的临界阈值水压定义。后一种方法对应于具有混合边界条件的经典理查兹方程。我们比较不同的方法在理论层面上确定的基本简化，是为系统的不同隔间：多孔介质，自由流动和他们的接口，并讨论如何不明确考虑的过程参数化。简化可以分为三组，这取决于是否考虑垂直通量的横向变化，是否考虑多孔介质中空气相的流动和运输，以及如何表示自由流和多孔介质之间的界面处的相互作用。简化的后果说明了在所附文件的数值模拟。
Evaporation is an important component of the soil water balance. It is composed of water flow and transport processes in a porous medium that are coupled with heat fluxes and free air flow. This work provides a comprehensive review of model concepts used in different research fields to describe evaporation. Concepts range from nonisothermal two‐phase flow, two‐component transport in the porous medium that is coupled with one‐phase flow, two‐component transport in the free air flow to isothermal liquid water flow in the porous medium with upper boundary conditions defined by a potential evaporation flux when available energy and transfer to the free airflow are limiting or by a critical threshold water pressure when soil water availability is limiting. The latter approach corresponds with the classical Richards equation with mixed boundary conditions. We compare the different approaches on a theoretical level by identifying the underlying simplifications that are made for the different compartments of the system: porous medium, free flow and their interface, and by discussing how processes not explicitly considered are parameterized. Simplifications can be grouped into three sets depending on whether lateral variations in vertical fluxes are considered, whether flow and transport in the air phase in the porous medium are considered, and depending on how the interaction at the interface between the free flow and the porous medium is represented. The consequences of the simplifications are illustrated by numerical simulations in an accompanying paper.