DOI: 10.1002/2017MS000931
Scopus记录号: 2-s2.0-85020737747
论文题名: The soil moisture velocity equation
作者: Ogden F ; L ; , Allen M ; B ; , Lai W ; , Zhu J ; , Seo M ; , Douglas C ; C ; , Talbot C ; A
刊名: Journal of Advances in Modeling Earth Systems
ISSN: 19422466
出版年: 2017
卷: 9, 期: 2 起始页码: 1473
结束页码: 1487
语种: 英语
英文关键词: Advection
; Capillarity
; Differential equations
; Earth atmosphere
; Groundwater
; Hydrology
; Inverse problems
; Mathematical techniques
; Models
; Moisture
; Moisture determination
; Numerical methods
; Ordinary differential equations
; Remote sensing
; Soil moisture
; Soils
; Solute transport
; Solutions
; Wetting
; Computationally efficient
; Equation
; Land atmosphere interaction
; Moisture content values
; Ordinary differential equation (ODE)
; Soil hydraulic properties
; Spatial discretizations
; Vadose
; Infiltration
; capillarity
; capillary pressure
; flux measurement
; groundwater
; hydraulic property
; hydrology
; mathematics
; modeling
; moisture content
; numerical method
; remote sensing
; Richards equation
; soil moisture
; vadose zone
; wetting front
英文摘要: Numerical solution of the one-dimensional Richards' equation is the recommended method for coupling groundwater to the atmosphere through the vadose zone in hyperresolution Earth system models, but requires fine spatial discretization, is computationally expensive, and may not converge due to mathematical degeneracy or when sharp wetting fronts occur. We transformed the one-dimensional Richards' equation into a new equation that describes the velocity of moisture content values in an unsaturated soil under the actions of capillarity and gravity. We call this new equation the Soil Moisture Velocity Equation (SMVE). The SMVE consists of two terms: an advection-like term that accounts for gravity and the integrated capillary drive of the wetting front, and a diffusion-like term that describes the flux due to the shape of the wetting front capillarity profile divided by the vertical gradient of the capillary pressure head. The SMVE advection-like term can be converted to a relatively easy to solve ordinary differential equation (ODE) using the method of lines and solved using a finite moisture-content discretization. Comparing against analytical solutions of Richards' equation shows that the SMVE advection-like term is >99% accurate for calculating infiltration fluxes neglecting the diffusion-like term. The ODE solution of the SMVE advection-like term is accurate, computationally efficient and reliable for calculating one-dimensional vadose zone fluxes in Earth system and large-scale coupled models of land-atmosphere interaction. It is also well suited for use in inverse problems such as when repeat remote sensing observations are used to infer soil hydraulic properties or soil moisture. © 2017. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75790
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
There are no files associated with this item.
作者单位: Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY, United States; Department of Mathematics, University of Wyoming, Laramie, WY, United States; Glenn Department of Civil Engineering, Clemson University, Clemson, SC, United States; Formerly at University of Wyoming, Laramie, WY, United States; U.S. Army Corps of Engineers, Engineer Research and Development Center, Vicksburg, MS, United States
Recommended Citation:
Ogden F,L,, Allen M,et al. The soil moisture velocity equation[J]. Journal of Advances in Modeling Earth Systems,2017-01-01,9(2)