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1. Coupled geotechnical-climatic design procedure for drilled shaft subjected to axial load

Author:
Vahidreza Mahmoudabadi; Nadarajah Ravichandran
Source:
Engineering geology 2020 v.264 pp. 105317
ISSN:
0013-7952
Subject:
Richards' equation,   etc   ; evapotranspiration; infiltration rate; rain; subsurface soil layers; water table; California; Utah;     Show all 8 Subjects
Abstract:
... In this paper, a novel procedure is proposed to incorporate the site-specific hydrological/climatic parameters into the geotechnical design of drilled shaft with sample applications in Riverside, CA and Salt Lake City, UT. The variation of degree of the saturation and/or matric suction due to the hydrological/climatic events was modeled using the one-dimensional Richards’ equation considering hist ...
DOI:
10.1016/j.enggeo.2019.105317

2. Finite analytic method for modeling variably saturated flows

Author:
Zaiyong Zhang; Wenke Wang; Chengcheng Gong; Tian-chyi Jim Yeh; Zhoufeng Wang; Yu-Li Wang; Li Chen
Source:
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. Hydraulic redistribution driven by roots: Modeling and simulation case for the Pantanal

Author:
Fernando da Silva Sallo; Osvaldo Borges Pinto Júnior; Higo José Dalmagro
Source:
International journal of ecohydrology & hydrobiology 2020 v.20 no.2 pp. 243-255
ISSN:
1642-3593
Subject:
Richards' equation,   etc   ; drainage; evapotranspiration; hydrologic cycle; models; rhizosphere; root systems; roots; soil water; water uptake; Pantanal;     Show all 11 Subjects
Abstract:
... Evapotranspiration is the major component of the water cycle excluding precipitation. Evapotranspiration sub-processes represent important paths of water which have been poorly investigated and may play an important role in the water cycle. Two of these sub-processes are root water uptake (RWU) and root hydraulic redistribution (RHR), which were modelled and numerically explored in this study. Bot ...
DOI:
10.1016/j.ecohyd.2019.12.005

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

Author:
Xiuyu Liang; Hongbin Zhan; You‐Kuan Zhang; Jin Liu
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

5. Retrieving global surface soil moisture from GRACE satellite gravity data

Author:
Morteza Sadeghi; Lun Gao; Ardeshir Ebtehaj; Jean-Pierre Wigneron; Wade T. Crow; John T. Reager; Arthur W. Warrick
Source:
Journal of hydrology 2020 v.584 pp. 124717
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; Soil Moisture and Ocean Salinity satellite; climate; data collection; gravity; models; radio waves; radiometry; remote sensing; soil water; water storage;     Show all 11 Subjects
Abstract:
... Passive microwave radiometry from space through missions such as the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) satellites is the most reliable means for mapping global surface soil moisture (SSM). Nonetheless, microwave SSM retrievals are uncertain over densely vegetated surfaces or areas with high radio frequency interference. This paper presents a new observ ...
DOI:
10.1016/j.jhydrol.2020.124717

6. Hydrological and thermal regime of a thin green roof system evaluated by physically-based model

Author:
Vojtech Skala; Michal Dohnal; Jana Votrubova; Tomas Vogel; Jaromir Dusek; Jan Sacha; Vladimira Jelinkova
Source:
Urban forestry & urban greening 2020 v.48 pp. 126582
ISSN:
1618-8667
Subject:
Richards' equation,   etc   ; Technosols; drainage; green roofs; heat island; heat transfer; mathematical models; physical models; porous media; rain; soil profiles; soil temperature; soil water; thermal properties; transpiration; vegetation cover; water flow; water storage; water uptake;     Show all 19 Subjects
Abstract:
... Green roofs, as an element of the green infrastructure, contribute to the urban heat island effect mitigation and the urban drainage outflow reduction. To achieve the desired functions, it is essential to understand the role of the individual roof layers and ensure their proper design.A physically-based model was used to assess the hydrological and thermal regime of two experimental green roof tes ...
DOI:
10.1016/j.ufug.2020.126582

7. Numerical Solution of Richards’ Equation: A Review of Advances and Challenges

Author:
Matthew W. Farthing; Fred L. Ogden
Source:
Soil Science Society of America journal 2017 v.81 no.6 pp. 1257-1269
ISSN:
0361-5995
Subject:
Richards' equation,   etc   ; air; capillarity; gravity; hydrology; porous media; soil; waste management;     Show all 8 Subjects
Abstract:
... The flow of water in partially saturated porous media is of importance in fields such as hydrology, agriculture, environment and waste management. It is also one of the most complex flows in nature. The Richards’ equation describes the flow of water in an unsaturated porous medium due to the actions of gravity and capillarity neglecting the flow of the non-wetting phase, usually air. Analytical so ...
DOI:
10.2136/sssaj2017.02.0058

8. Functional Extremum Solution and Parameter Estimation for One-Dimensional Vertical Infiltration using the Brooks–Corey Model

Author:
Lijun Su; Xin Yang; Quanjiu Wang; Xinqiang Qin; Beibei Zhou; Yuyang Shan
Source:
Soil Science Society of America journal 2018 v.82 no.6 pp. 1319-1332
ISSN:
0361-5995
Subject:
Richards' equation,   etc   ; absorption; analytical methods; infiltration rate; irrigation; saturated hydraulic conductivity; soil water; soil water content; wetting front;     Show all 9 Subjects
Abstract:
... A simple analytical solution of one-dimensional vertical infiltration of soil water is of great importance for the estimation of soil hydraulic properties and for precision irrigation. We use a new approximate analytical method based on the principle of least action and the variational principle for simulating the vertical infiltration of water in unsaturated soil for a constant-saturation upper b ...
DOI:
10.2136/sssaj2018.01.0016

9. Influence of time-dependent ground surface flux on aquifer recharge with a vadose zone injection well

Author:
Cuiting Qi; Hongbin Zhan; Xiuyu Liang; Chong Ma
Source:
Journal of hydrology 2020 v.584 pp. 124739
ISSN:
0022-1694
Subject:
Richards' equation,   etc   ; anisotropy; aquifers; arid zones; evapotranspiration; finite element analysis; groundwater recharge; hydraulic conductivity; mathematical models; saturated flow; unsaturated flow; vadose zone; water management; water table;     Show all 14 Subjects
Abstract:
... Vadose zone well (VZW) injection is an effective method for aquifer recharge in semiarid and arid regions where groundwater table is deep or sufficiently permeable soils and/or sufficiently large land areas for surface infiltration are not available. Several analytical and numerical models have been developed for the injection well in the vadose zone. However, those models usually ignore the groun ...
DOI:
10.1016/j.jhydrol.2020.124739

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

Author:
Wencai Dong; Song Cui; Qiang Fu; Quanjiu Wang; Chengpeng Cao
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

11. Estimating evapotranspiration parameters by inverse modelling and non-linear optimization

Author:
Angaleeswari M.; Ravikumar V.
Source:
Agricultural water management 2019 v.223 no. pp. 105681
ISSN:
0378-3774
Subject:
Richards' equation,   etc   ; computer software; evapotranspiration; fertigation; guidelines; irrigation scheduling; logging; microirrigation; models; paddies; planning; rhizosphere; root growth; soil water; soil water movement; temporal variation; unsaturated hydraulic conductivity; volumetric water content; water uptake;     Show all 19 Subjects
Abstract:
... The use of models like HYDRUS in planning irrigation and fertigation scheduling is increasingly researched. Simulation of the root zone processes using HYDRUS largely depends on characterizing parameters related to unsaturated hydraulic conductivity, root growth and water uptake dynamics. A methodology for estimating evapotranspiration parameters for drip irrigated paddy is developed in the presen ...
DOI:
10.1016/j.agwat.2019.06.016

12. Regional Quasi-Three-Dimensional Unsaturated-Saturated Water Flow Model Based on a Vertical-Horizontal Splitting Concept

Author:
Yan Zhu; Liangsheng Shi; Jingwei Wu; Ming Ye; Lihong Cui; Jinzhong Yang
Source:
Water 2016 v.8 no.5 pp. -
ISSN:
2073-4441
Subject:
Richards' equation,   etc   ; mathematical models; water flow; water table;     Show all 4 Subjects
Abstract:
... Due to the high nonlinearity of the three-dimensional (3-D) unsaturated-saturated water flow equation, using a fully 3-D numerical model is computationally expensive for large scale applications. A new unsaturated-saturated water flow model is developed in this paper based on the vertical/horizontal splitting (VHS) concept to split the 3-D unsaturated-saturated Richards’ equation into a two-dimens ...
DOI:
10.3390/w8050195

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

Author:
Keith R. Daly; Saoirse R. Tracy; Neil M.J. Crout; Stefan Mairhofer; Tony P. Pridmore; Sacha J. Mooney; Tiina Roose
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

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

Author:
Hoori Ajami; Urooj Khan; Narendra K. Tuteja; Ashish Sharma
Source:
Environmental modelling & software 2016 v.85 pp. 319-331
ISSN:
1364-8152
Subject:
Richards' equation,   etc   ; topography; highlands; watersheds; soil water; land cover; computer software; runoff; hydrologic models;     Show all 9 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

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

Author:
Seyed Mohammad Hossein Jazayeri Shoushtari; Peter Nielsen; Nick Cartwright; Pierre Perrochet
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

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

Author:
Hyunuk An; Tran The Viet; Giha Lee; Yeonsu Kim; Minseok Kim; Seongjin Noh; Jaekyoung Noh
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

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

Author:
Mark S. Pleasants; Thijs J. Kelleners; Noriaki Ohara
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

18. A Percolation‐Based Approach to Scaling Infiltration and Evapotranspiration

Author:
Allen G. Hunt; Ran Holtzman; Behzad Ghanbarian
Source:
Water 2017 v.9 no.2 pp. -
ISSN:
2073-4441
Subject:
Richards' equation,   etc   ; evapotranspiration; growing season; hydraulic conductivity; mathematical theory; plant height; porosity; root growth; root tips; saturated conditions; topology; transient flow; transpiration; vegetation;     Show all 14 Subjects
Abstract:
... Optimal flow paths obtained from percolation theory provide a powerful tool that can be used to characterize properties associated with flow such as soil hydraulic conductivity, as well as other properties influenced by flow connectivity and topology. A recently proposed scaling theory for vegetation growth appeals to the tortuosity of optimal paths from percolation theory to define the spatio‐tem ...
DOI:
10.3390/w9020104

19. Modified Richards’ Equation to Improve Estimates of Soil Moisture in Two-Layered Soils after Infiltration

Author:
Honglin Zhu; Tingxi Liu; Baolin Xue; Yinglan A.; Guoqiang Wang
Source:
Water 2018 v.10 no.9 pp. -
ISSN:
2073-4441
Subject:
Richards' equation,   etc   ; environmental factors; evapotranspiration; hydraulic conductivity; hydrologic cycle; hydrologic models; overland flow; porosity; rain; soil depth; soil erosion; soil water; spatial variation;     Show all 13 Subjects
Abstract:
... Soil moisture distribution plays a significant role in soil erosion, evapotranspiration, and overland flow. Infiltration is a main component of the hydrological cycle, and simulations of soil moisture can improve infiltration process modeling. Different environmental factors affect soil moisture distribution in different soil layers. Soil moisture distribution is influenced mainly by soil properti ...
DOI:
10.3390/w10091174

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

Author:
Hyunuk An; Yutaka Ichikawa; Yasuto Tachikawa; Michiharu Shiiba
Source:
Journal of hydrology 2012 v.470-471 no. 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