Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.jhydrol.2012.05.039 ; 10.1016/j.jhydrol.2012.05.039 |
Estimating groundwater recharge through unsaturated flow modelling: Sensitivity to boundary conditions and vertical discretization; Estimating groundwater recharge through unsaturated flow modelling: Sensitivity to boundary conditions and vertical discretization | |
Carrera-Hernandez, J. J.1; Smerdon, B. D.2; Mendoza, C. A.3 | |
通讯作者 | Carrera-Hernandez, J. J. ; Carrera-Hernandez, J. J. |
来源期刊 | JOURNAL OF HYDROLOGY ; JOURNAL OF HYDROLOGY |
ISSN | 0022-1694 ; 0022-1694 |
EISSN | 1879-2707 ; 1879-2707 |
出版年 | 2012 ; 2012 |
卷号 | 452页码:90-101 |
英文摘要 | Unsaturated flow modelling is increasingly being used to estimate potential groundwater recharge. A review of previous studies found that unit-gradient and fixed water table lower boundary conditions have been applied to models of both constant and variable vertical grid spacing (discretization). In order to provide a general guidance, this work studies the effect of both discretization and boundary conditions on simulation times and estimated fluxes at the water table, using one-dimensional models of 2, 4, 6, and 12 m comprised of sand, sandy loam, loamy sand, and loam. The study uses climatological data from the Boreal Plain of northern Alberta, Canada. Because of the long-term average water deficit and the thick unconsolidated glacial deposits, unsaturated flow is expected to be vertical, both downward and upward, and inter-annual changes in water storage will be important. Long-term simulations (1919-2007) that comprised both wet and dry cycles, reveal that when a variable vertical discretization at both the top and bottom of the columns (varying from 0.1 to 10 cm) is utilized, a balance between simulation accuracy and running time can be achieved. It is also found that whenever the unsaturated flow modelling approach is used to estimate potential groundwater recharge, a fixed-head lower boundary condition should be selected because it also allows upward flux from the water table during dry periods, a situation that prevails on both sub-humid and semi-arid areas, where accurate groundwater recharge estimates are needed the most. However, it should be kept in mind that the use of a fixed water table is a simple representation of the regional water table, which in reality interacts with the regional groundwater flow and surface water bodies (e.g., lakes and wetlands). (C) 2012 Elsevier B.V. All rights reserved. ; Unsaturated flow modelling is increasingly being used to estimate potential groundwater recharge. A review of previous studies found that unit-gradient and fixed water table lower boundary conditions have been applied to models of both constant and variable vertical grid spacing (discretization). In order to provide a general guidance, this work studies the effect of both discretization and boundary conditions on simulation times and estimated fluxes at the water table, using one-dimensional models of 2, 4, 6, and 12 m comprised of sand, sandy loam, loamy sand, and loam. The study uses climatological data from the Boreal Plain of northern Alberta, Canada. Because of the long-term average water deficit and the thick unconsolidated glacial deposits, unsaturated flow is expected to be vertical, both downward and upward, and inter-annual changes in water storage will be important. Long-term simulations (1919-2007) that comprised both wet and dry cycles, reveal that when a variable vertical discretization at both the top and bottom of the columns (varying from 0.1 to 10 cm) is utilized, a balance between simulation accuracy and running time can be achieved. It is also found that whenever the unsaturated flow modelling approach is used to estimate potential groundwater recharge, a fixed-head lower boundary condition should be selected because it also allows upward flux from the water table during dry periods, a situation that prevails on both sub-humid and semi-arid areas, where accurate groundwater recharge estimates are needed the most. However, it should be kept in mind that the use of a fixed water table is a simple representation of the regional water table, which in reality interacts with the regional groundwater flow and surface water bodies (e.g., lakes and wetlands). (C) 2012 Elsevier B.V. All rights reserved. |
英文关键词 | Groundwater recharge Groundwater recharge Unsaturated flow Unsaturated flow Numerical modelling Numerical modelling Discretization Discretization Boundary conditions Boundary conditions |
类型 | Article ; Article |
语种 | 英语 ; 英语 |
国家 | Mexico ; Mexico ; Australia ; Australia ; Canada ; Canada |
收录类别 | SCI-E ; SCI-E |
WOS记录号 | WOS:000306777500009 ; WOS:000306777500009 |
WOS关键词 | TEST NUMERICAL-MODELS ; TEST NUMERICAL-MODELS ; RICHARDS EQUATION ; RICHARDS EQUATION ; ANALYTICAL BENCHMARKS ; ANALYTICAL BENCHMARKS ; BOREAL PLAINS ; BOREAL PLAINS ; WATER-FLOW ; WATER-FLOW ; SOILS ; SOILS ; SIMULATION ; SIMULATION ; INFILTRATION ; INFILTRATION ; TRANSPORT ; TRANSPORT ; ZONE ; ZONE |
WOS类目 | Engineering, Civil ; Engineering, Civil ; Geosciences, Multidisciplinary ; Geosciences, Multidisciplinary ; Water Resources ; Water Resources |
WOS研究方向 | Engineering ; Engineering ; Geology ; Geology ; Water Resources ; Water Resources |
来源机构 | Commonwealth Scientific and Industrial Research Organisation ; Universidad Nacional Autónoma de México |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/173679 |
作者单位 | 1.IPICyT, San Luis Potosi, Mexico; 2.CSIRO Land & Water, Glen Osmond, SA, Australia; 3.Univ Alberta, Edmonton, AB, Canada |
推荐引用方式 GB/T 7714 | Carrera-Hernandez, J. J.,Smerdon, B. D.,Mendoza, C. A.. Estimating groundwater recharge through unsaturated flow modelling: Sensitivity to boundary conditions and vertical discretization, Estimating groundwater recharge through unsaturated flow modelling: Sensitivity to boundary conditions and vertical discretization[J]. Commonwealth Scientific and Industrial Research Organisation, Universidad Nacional Autónoma de México,2012, 2012,452, 452:90-101, 90-101. |
APA | Carrera-Hernandez, J. J.,Smerdon, B. D.,&Mendoza, C. A..(2012).Estimating groundwater recharge through unsaturated flow modelling: Sensitivity to boundary conditions and vertical discretization.JOURNAL OF HYDROLOGY,452,90-101. |
MLA | Carrera-Hernandez, J. J.,et al."Estimating groundwater recharge through unsaturated flow modelling: Sensitivity to boundary conditions and vertical discretization".JOURNAL OF HYDROLOGY 452(2012):90-101. |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。