DOI: 10.5194/hess-20-3441-2016
Scopus记录号: 2-s2.0-84984889438
论文题名: A thermodynamic formulation of root water uptake
作者: Hildebrandt A ; , Kleidon A ; , Bechmann M
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2016
卷: 20, 期: 8 起始页码: 3441
结束页码: 3454
语种: 英语
Scopus关键词: Flow of water
; Soil moisture
; Soils
; Water supply systems
; Dissipative loss
; Hydraulic energy
; Root-water uptake
; Soil water content
; Soil-water distribution
; Storage changes
; Thermodynamic evaluation
; Thermodynamic formulation
; Thermodynamics
; dissipation
; energy flow
; heterogeneity
; hydraulics
; root system
; soil water
; thermodynamics
; water flow
; water uptake
英文摘要: By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how root water uptake can be evaluated thermodynamically and demonstrate that this evaluation provides additional insights into the factors that impede root water uptake. We derive an expression that relates the energy export at the base of the root system to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We illustrate this thermodynamic formulation using an idealized setup of scenarios with a simple model. In these scenarios, we demonstrate why heterogeneity in soil water distribution and rooting properties affect the impediment of water flow even though the mean soil water content and rooting properties are the same across the scenarios. The effects of heterogeneity can clearly be identified in the thermodynamics of the system in terms of differences in dissipative losses and hydraulic energy, resulting in an earlier start of water limitation in the drying cycle. We conclude that this thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path, which goes beyond resistances and also accounts for the role of heterogeneity in soil water distribution. © 2016 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78752
Appears in Collections: 气候变化事实与影响
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作者单位: Friedrich-Schiller-Universität, Jena, Germany; Max-Planck-Institut für Biogeochemie, Jena, Germany
Recommended Citation:
Hildebrandt A,, Kleidon A,, Bechmann M. A thermodynamic formulation of root water uptake[J]. Hydrology and Earth System Sciences,2016-01-01,20(8)