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1. Underdamped slug tests with unsaturated‐saturated flows by considering effects of wellbore skins

Author:
Liang, Xiuyu; Zhan, Hongbin; Zhang, You‐Kuan; Liu, Jin
Source:
Hydrological processes 2018 v.32 no.7 pp. 968-980
ISSN:
0885-6087
Subject:
Richards' equation,   etc   ; aquifers; unsaturated flow; water table;     Show all 4 Subjects
Abstract:
... An analytical solution is presented for the slug tests conducted in a partially penetrating well in an unconfined aquifer affected from above by an unsaturated zone. The solution considers the effects of wellbore skin and oscillatory responses on underdamped slug tests. The flow in the saturated zone is described by a two‐dimensional, axially symmetric governing equation, and the flow in the unsat ...
DOI:
10.1002/hyp.11471

2. Finite analytic method for modeling variably saturated flows

Author:
Zhang, Zaiyong; Wang, Wenke; Gong, Chengcheng; Yeh, Tian-chyi Jim; Wang, Zhoufeng; Wang, Yu-Li; Chen, Li
Source:
The Science of the total environment 2018 v.621 pp. 1151-1162
ISSN:
0048-9697
Subject:
Richards' equation,   etc   ; differential equation; field experimentation; models; unsaturated flow;     Show all 5 Subjects
Abstract:
... This paper develops a finite analytic method (FAM) for solving the two-dimensional Richards' equation. The FAM incorporates the analytic solution in local elements to formulate the algebraic representation of the partial differential equation of unsaturated flow so as to effectively control both numerical oscillation and dispersion. The FAM model is then verified using four examples, in which the ...
DOI:
10.1016/j.scitotenv.2017.10.112

3. Modelling soil solute release and transport in run‐off on a loessial slope with and without surface stones

Author:
Dong, Wencai; Cui, Song; Fu, Qiang; Wang, Quanjiu; Cao, Chengpeng
Source:
Hydrological processes 2018 v.32 no.10 pp. 1391-1400
ISSN:
0885-6087
Subject:
Richards' equation,   etc   ; field experimentation; mechanistic models; overland flow; runoff; soil profiles; solutes; surface area;     Show all 8 Subjects
Abstract:
... Stone covers on loessial slopes can increase the time of infiltration by slowing the velocity of the overland flow, which reduces the transport of solutes, but few mechanistic models have been tested under water‐scouring conditions. We carried out field experiments to test a previously proposed, physically based model of water and solute transport. The area of soil infiltration was calculated from ...
DOI:
10.1002/hyp.11497

4. Quantification of root water uptake in soil using X‐ray computed tomography and image‐based modelling

Author:
Daly, Keith R.; Tracy, Saoirse R.; Crout, Neil M.J.; Mairhofer, Stefan; Pridmore, Tony P.; Mooney, Sacha J.; Roose, Tiina
Source:
Plant, cell and environment 2018 v.41 no.1 pp. 121-133
ISSN:
0140-7791
Subject:
Richards' equation,   etc   ; computed tomography; geometry; models; rhizosphere; root systems; roots; soil hydraulic properties; soil types; water uptake; wheat;     Show all 11 Subjects
Abstract:
... Spatially averaged models of root–soil interactions are often used to calculate plant water uptake. Using a combination of X‐ray computed tomography (CT) and image‐based modelling, we tested the accuracy of this spatial averaging by directly calculating plant water uptake for young wheat plants in two soil types. The root system was imaged using X‐ray CT at 2, 4, 6, 8 and 12 d after transplanting. ...
DOI:
10.1111/pce.12983

5. Power series solution for ponded infiltration on sloping surfaces

Author:
Mollerup, Mikkel; Hansen, Søren
Source:
Journal of hydrology 2012 v.464-465 pp. 431-437
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; surface water;     Show all 2 Subject
Abstract:
... Recently it has been shown that the Philip power series solution can also be applied for falling head ponded infiltration (Mollerup and Hansen, 2007) or more generally for variable head (VH) ponded infiltration on flat surfaces (Mollerup, 2007). In this study, it is shown that the power series solution can also be applied for VH ponded infiltration on sloping surfaces. Numerical simulations have b ...
DOI:
10.1016/j.jhydrol.2012.07.031

6. Periodic seepage face formation and water pressure distribution along a vertical boundary of an aquifer

Author:
Jazayeri Shoushtari, Seyed Mohammad Hossein; Nielsen, Peter; Cartwright, Nick; Perrochet, Pierre
Source:
Journal of hydrology 2015 v.523 pp. 24-33
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; aquifers; drainage; hydraulic conductivity; models; sand; water table;     Show all 7 Subjects
Abstract:
... Detailed measurements of the piezometric head from sand flume experiments of an idealised coastal aquifer forced by a simple harmonic boundary condition across a vertical boundary are presented. The measurements focus on the pore pressures very close to the interface (x=0.01m) and throw light on the details of the boundary condition, particularly with respect to meniscus suction and seepage face f ...
DOI:
10.1016/j.jhydrol.2015.01.027

7. Analysis of snowpack dynamics during the spring melt season for a sub‐alpine site using point measurements and numerical modeling

Author:
Pleasants, Mark S.; Kelleners, Thijs J.; Ohara, Noriaki
Source:
Hydrological processes 2017 v.31 no.25 pp. 4568-4585
ISSN:
0885-6087
Subject:
Richards' equation,   etc   ; capillarity; hydrology; liquids; mathematical models; melting; prediction; snow; snowpack; spring; temperature; time series analysis; Wyoming;     Show all 13 Subjects
Abstract:
... Snowpack dynamics through October 2014–June 2017 were described for a forested, sub‐alpine field site in southeastern Wyoming. Point measurements of wetness and density were combined with numerical modeling and continuous time series of snow depth, snow temperature, and snowpack outflow to identify 5 major classes of distinct snowpack conditions. Class (i) is characterized by no snowpack outflow a ...
DOI:
10.1002/hyp.11379

8. Comparison between iteration schemes for three-dimensional coordinate-transformed saturated–unsaturated flow model

Author:
An, Hyunuk; Ichikawa, Yutaka; Tachikawa, Yasuto; Shiiba, Michiharu
Source:
Journal of hydrology 2012 v.470-471 pp. 212-226
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; models; porous media;     Show all 3 Subjects
Abstract:
... Three different iteration methods for a three-dimensional coordinate-transformed saturated–unsaturated flow model are compared in this study. The Picard and Newton iteration methods are the common approaches for solving Richards’ equation. The Picard method is simple to implement and cost-efficient (on an individual iteration basis). However it converges slower than the Newton method. On the other ...
DOI:
10.1016/j.jhydrol.2012.08.056

9. Approximate furrow infiltration model for time-variable ponding depth

Author:
Bautista, E.; Warrick, A. W.; Schlegel, J. L.; Thorp, K. R.; Hunsaker, D. J.
Source:
Journal of Irrigation and Drainage Engineering 2016 v.142 no.11 pp. 1-11
ISSN:
0733-9437
Subject:
Richards' equation,   etc   ; furrow irrigation; furrows; geometry; hydrologic models; infiltration (hydrology); soil hydraulic properties; water flow;     Show all 8 Subjects
Abstract:
... A methodology is proposed for estimating furrow infiltration under time-variable ponding depth. The methodology approximates the solution to the two-dimensional Richards equation, and is a modification of a procedure that was originally proposed for computing infiltration under constant ponding depth. Two computational approaches were developed and tested using several combinations of soil hydraul ...
Handle:
10113/5801859
DOI:
https://doi.org/10.1061/(ASCE)IR.1943-4774.0001057

10. Development of a computationally efficient semi-distributed hydrologic modeling application for soil moisture, lateral flow and runoff simulation

Author:
Ajami, Hoori; Khan, Urooj; Tuteja, Narendra K.; Sharma, Ashish
Source:
Environmental modelling & software 2016 v.85 pp. 319-331
ISSN:
1364-8152
Subject:
Richards' equation,   etc   ; computer software; highlands; hydrologic models; land cover; runoff; soil water; topography; water balance; watersheds;     Show all 10 Subjects
Abstract:
... A new automated workflow based computationally efficient hydrologic modeling application is developed for soil moisture and runoff simulation. The spatially distributed conceptual framework underpinning the Soil Moisture And Runoff simulation Toolkit (SMART) resolves water balance in large upland catchments where topography and land cover are significant drivers of rainfall-runoff transformations. ...
DOI:
10.1016/j.envsoft.2016.09.002

11. Development of time-variant landslide-prediction software considering three-dimensional subsurface unsaturated flow

Author:
An, Hyunuk; Viet, Tran The; Lee, Giha; Kim, Yeonsu; Kim, Minseok; Noh, Seongjin; Noh, Jaekyoung
Source:
Environmental modelling & software 2016 v.85 pp. 172-183
ISSN:
1364-8152
Subject:
Richards' equation,   etc   ; computer software; environmental models; landslides; prediction; subsurface flow; unsaturated flow; user interface; South Korea;     Show all 9 Subjects
Abstract:
... An accurate landslide-susceptibility assessment is fundamental for preventing landslides and minimizing damage. In this study, a new time-variant slope-stability (TiVaSS) model for landslide prediction is developed. A three-dimensional (3D) subsurface flow model is coupled with the infinite slope-stability model to consider the effect of horizontal water movement in the subsurface. A 3D Richards' ...
DOI:
10.1016/j.envsoft.2016.08.009

12. Impact of Lower Boundary Condition of Richards' Equation on Water, Energy, and Soil Carbon Based on Coupling Land Surface and Biogeochemical Models

Author:
CHEN, Xiangdong; LIANG, Xu; XIA, Jun; SHE, Dunxian
Source:
Pedosphere 2018 v.28 no.3 pp. 497-510
ISSN:
1002-0160
Subject:
Richards' equation,   etc   ; biogeochemical cycles; carbon; energy balance; evaporation; heat transfer; hydrologic cycle; models; nitrogen; phosphorus; runoff; silt loam soils; soil permeability; soil respiration; soil temperature; soil water; soil water movement;     Show all 17 Subjects
Abstract:
... Soil moisture has a significant influence on water, energy, and carbon biogeochemical cycles. A numerical method for solving Richards' equation is usually used for simulating soil moisture. Selection of a lower boundary condition for Richards' equation will further affect the simulation results for soil moisture, water cycle, energy balance, and carbon biogeochemical processes. In this study, the ...
DOI:
10.1016/S1002-0160(17)60371-0

13. Modeling unsaturated zone flow and runoff processes by integrating MODFLOW-LGR and VSF, and creating the new CFL package

Author:
Borsi, I.; Rossetto, R.; Schifani, C.; Hill, M.C.
Source:
Journal of hydrology 2013 v.488 pp. 33-47
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; models; overland flow; runoff; saturated flow; unsaturated flow;     Show all 6 Subjects
Abstract:
... In this paper two modifications to the MODFLOW code are presented. One concerns an extension of Local Grid Refinement (LGR) to Variable Saturated Flow process (VSF) capability. This modification allows the user to solve the 3D Richards’ equation only in selected parts of the model domain. The second modification introduces a new package, named CFL (Cascading Flow), which improves the computation o ...
DOI:
10.1016/j.jhydrol.2013.02.020

14. A soil-plant model applied to phytoremediation of metals

Author:
Lugli, Francesco; Mahler, Claudio Fernando
Source:
International journal of phytoremediation 2016 v.18 no.4 pp. 295-307
ISSN:
1549-7879
Subject:
Richards' equation,   etc   ; Chrysopogon zizanioides; cadmium; lead; leaf area index; metal ions; models; nickel; phytoremediation; plant tissues; polluted soils; soil-plant interactions; solar radiation; solutes; transpiration; water flow; zinc;     Show all 17 Subjects
Abstract:
... This study reports a phytoremediation pot experiment using an open-source program. Unsaturated water flow was described by the Richards' equation and solute transport by the advection-dispersion equation. Sink terms in the governing flow and transport equations accounted for root water and solute uptake, respectively. Experimental data were related to application of Vetiver grass to soil contamina ...
DOI:
10.1080/15226514.2015.1094445

15. A finite-element algorithm for modeling variably saturated flows

Author:
Wu, Mengxi
Source:
Journal of hydrology 2010 v.394 no.3-4 pp. 315-323
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; algorithms; models; saturated flow; seepage; water table;     Show all 6 Subjects
Abstract:
... A general numerical algorithm in the context of finite element scheme is developed to solve Richards' equation, in which a mass-conservative, modified head based scheme (MHB) is proposed to approximate the governing equation, and mass-lumping techniques are used to keep the numerical simulation stable. The MHB scheme is compared with the modified Picard iteration scheme (MPI) in a ponding infiltra ...
DOI:
10.1016/j.jhydrol.2010.09.004

16. Hillslope hydrograph analysis using synthetic and natural oxygen-18 signatures

Author:
Dusek, Jaromir; Vogel, Tomas; Sanda, Martin
Source:
Journal of hydrology 2012 v.475 pp. 415-427
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; mixing; prediction; preferential flow; rain; runoff; saturated flow; soil profiles; soil water; subsurface flow;     Show all 10 Subjects
Abstract:
... Shallow subsurface runoff is one of the most important mechanisms determining hydrological responses of headwater catchments to rainstorms. In this study, a simplified approach combining one-dimensional dual-continuum vertical flow in a variably saturated soil profile and one-dimensional saturated flow along the soil–bedrock interface was used to study rainfall–runoff events at an experimental hil ...
DOI:
10.1016/j.jhydrol.2012.10.025

17. An Object-oriented computational framework for the simulation of variably saturated flow in soils, using a reduced complexity model

Author:
Anagnostopoulos, Grigorios G.; Burlando, Paolo
Source:
Environmental modelling & software 2012 v.38 pp. 191-202
ISSN:
1364-8152
Subject:
Richards' equation,   etc   ; agricultural soils; computer software; environmental models; landslides; porous media; prediction; saturated flow; solutes;     Show all 9 Subjects
Abstract:
... A simple and efficient computational modelling framework is presented for the simulation of variably saturated flows in porous media, which is not based on a conventional numerical solution of the Richards' equation. The computational domain is discretised with a regular grid and simple rules govern the flow dynamics. Each cell can have distinct hydraulic properties and its state depends only on t ...
DOI:
10.1016/j.envsoft.2012.06.002

18. Additional scaled solutions to Richards’ equation for infiltration and drainage

Author:
Sadeghi, M.; Ghahraman, B.; Ziaei, A.N.; Davary, K.; Reichardt, K.
Source:
Soil & tillage research 2012 v.119 pp. 60-69
ISSN:
0167-1987
Subject:
Richards' equation,   etc   ; clay; drainage; sandy soils; soil profiles; soil properties; soil quality; soil water; unsaturated flow;     Show all 9 Subjects
Abstract:
... Warrick and Hussen developed in the nineties of the last century a method to scale Richards’ equation (RE) for similar soils. In this paper, new scaled solutions are added to the method of Warrick and Hussen considering a wider range of soils regardless of their dissimilarity. Gardner–Kozeny hydraulic functions are adopted instead of Brooks–Corey functions used originally by Warrick and Huss ...
DOI:
10.1016/j.still.2011.12.004

19. Modeling Variably Saturated Subsurface Solute Transport with MODFLOW‐UZF and MT3DMS

Author:
Morway, Eric D.; Niswonger, Richard G.; Langevin, Christian D.; Bailey, Ryan T.; Healy, Richard W.
Source:
Ground water 2013 v.51 no.2 pp. 237-251
ISSN:
0017-467X
Subject:
Richards' equation,   etc   ; groundwater flow; hydrologic models; parameter uncertainty; saturated flow; simulation models; solutes; uncertainty analysis; United States;     Show all 9 Subjects
Abstract:
... The MT3DMS groundwater solute transport model was modified to simulate solute transport in the unsaturated zone by incorporating the unsaturated‐zone flow (UZF1) package developed for MODFLOW. The modified MT3DMS code uses a volume‐averaged approach in which Lagrangian‐based UZF1 fluid fluxes and storage changes are mapped onto a fixed grid. Referred to as UZF‐MT3DMS, the linked model was tested a ...
DOI:
10.1111/j.1745-6584.2012.00971.x
PubMed:
22834908

20. Observations of long term air entrapment affecting runoff and water table

Author:
Zhang, Jing; Shah, Nirjhar; Ross, Mark A.
Source:
International journal of water 2009 v.5 no.2 pp. 140-162
ISSN:
1465-6620
Subject:
Richards' equation,   etc   ; air; mathematical models; runoff; water table;     Show all 5 Subjects
Abstract:
... Air entrapment plays a significant role in controlling infiltration and observed depth to water table in shallow water table environments. The current study incorporates multi-event field measurements with varying antecedent conditions and numerical modelling, using HYDRUS-1D to quantify the variation of air pressurisation values. The observations of water table in the field data depart significan ...
DOI:
10.1504/IJW.2009.028723