One-dimensional Water Flow Research Articles

EFFECT OF DRYING SPEED ON THE DESATURATION OF SWELLING ROCK

The paper presents the results of a numerical study of the influence of drying speed and hydraulic conductivity of swelling rock on the development of the desaturated zone. Swelling rock refers to natural material in which montmorillonite is the predominant type of mineral. Previous tests have unequivocally shown that a fully saturated swelling rock with a high swelling potential will not swell when wetted with water of the same chemical composition as the pore water. The swelling potential can be activated only after the desaturation of the swelling rock. The geohazard of swelling of such materials represents a very serious problem. The behavior of swelling rock is modeled as a combined hydraulic-mechanical process that includes vertical one-dimensional water flow in saturated and unsaturated conditions, with a change in the volume due to a change in the water content. As part of previously conducted laboratory research, a model of swelling was developed, which realistically represents the behavior of swelling material at the level of laboratory samples. With the developed model, it is possible to forecast the changes in moisture content that will occur during drying at the depth of the desaturated zone. Numerical simulations have clearly shown that the depth of the desaturated zone depends on the drying speed, that is, that significant depths of the desaturated zones can only be realized at low and long-term drying speeds. With the increase in the hydraulic conductivity of the swelling rock, the depth of the desaturated zone increases, and the time required for the development of such a zone increases to the same extent.

Inverse modeling of frequency domain-based one-dimensional soil water flow in layered soils

Soils are heterogeneous at multiple scales. Estimates of spatially varying saturated hydraulic conductivity (Ks) of soils dictate the resolution of modeling water flux based on the Richardson-Richards equation (RRE), but direct measurements of Ks everywhere in a field are practically impossible. As a result, this study develops an inverse approach to estimate spatially varying Ks utilizing soil moisture observations driven by periodic weather variability at different frequencies. Using a numerical solution to vertical, one-dimensional RRE based on Gardner-Kozeny (GK) model in a heterogeneous soil with periodic flux, we investigate the spatial cross-correlation between Ks and observations (the amplitude or phase shift) of soil moisture fluctuation at different frequencies without high computational cost in the conventional time-domain model. These correlation patterns vary with the spatial location and frequency, suggesting that soil moisture fluctuations at different frequencies at one monitoring location carry non-redundant information about the heterogeneous distribution of Ks. Guided by cross-correlation maps, several inverse experiments reveal the effectiveness of multi-frequency data of soil moisture fluctuation for mapping the heterogeneous distribution of Ks. Monte Carlo simulations suggest that multi-frequency data can provide non-redundant and useful information about the estimation of heterogeneous Ks. Synthetic data based on a commonly-applied nonlinear van Genuchten-Mualem (VG) model is then tested in our inversion algorithm. The results indicate that the spatial pattern of the inverted GK Ks is very similar to that of the VG Ks, although these two parameters are inherently not identical since they are used in two different models. In addition, the inverted GK Ks can successfully predict the soil moisture fluctuation of frequencies that were not used in the inversion. Despite having no field experiments to validate this model, we believe this is the first attempt to conduct frequency-domain inverse modeling in vadose zone hydrology using soil moisture fluctuation.

A hybrid 1D-2D Lagrangian solver with moving coupling to simulate dam-break flow

In dam-break problems, two-dimensional (2D) models on the vertical plane appropriately capture the non-hydrostatic pressure distribution but with a high computational cost. This study presents a hybrid Lagrangian solver of one-dimensional (1D) shallow water flow and a 2D large-eddy simulation with a sub-particle scale to simulate dam-break flows over frictional beds. The proposed 1D-2D hybrid scheme is a useful trade-off between the accuracy of the 2D models on the vertical plane and the computational efficiency of 1D shallow water equations models. The configuration of sub-domains is established so that the 1D solves the regions with dominantly hydrostatic pressure, while the 2D solver accounts for the non-hydrostaticity. A moving coupling method is introduced based on two-layer shallow water equations with a uniform velocity distribution that constructs two sub-domains, including inner and outer zones in the section coupling model (SCM), or upper and lower layers within the layer coupling model (LCM). Then, the region with high vertical accelerations is substituted by the 2D model in the SCM or mixed SCM-LCM in which the overlapping zone and boundary interface move with time, based on the 1D flow feature. Also, a new method is proposed to deal with irregular boundary interfaces in the LCM while satisfying the momentum transfer. The present hybrid model is advantageous as it meets mass conservation, and there is no need for typical inflow/outflow boundary conditions at the coupling interfaces for simulating dam-break waves. Moving particle simulation (MPS) is utilized to solve the Lagrangian equations, which is advantageous in dealing with free-surface problems with large deformation. The model validation reveals that the hybrid results of water depths are in very good agreement with observed data and those obtained from the 2D model for selected dam-break flows with the ratio of initial depths downstream to upstream up to 0.4. In this respect, the average root-mean-square-error (RMSE) is computed at 8.09 mm in the SCM, 8.16 mm in the mixed SCM-LCM, and 7.48 mm in the pure 2D model, while both hybrid models save the computational time by 55% compared to the 2D model. Moreover, the mixed SCM-LCM preserves the nonlinearity of the wavefront over long times, whereas the SCM converts the wavefront into a shockwave considering the same number of fluid particles.

Field variation of groundwater recharge and its uncertainty via multiple tracers' method in deep loess vadose zone

Accurate estimation of groundwater recharge is a precondition for assessing its spatial variation at different scales, especially field scale. In the field, the limitations and uncertainties of different methods are first evaluated based on site-specific conditions. In this study, we evaluated field variation in groundwater recharge via multiple tracers in the deep vadose zone on the Chinese Loess Plateau. Five deep soil profiles (approximately 20 m deep) were collected in the field. Soil water content and particle compositions were measured to analyse soil variation, and soil water isotope (3H, 18O, and 2H) and anion (NO3− and Cl−) profiles were used to estimate recharge rates. Distinct peaks in soil water isotope and nitrate profiles indicated a vertical one-dimensional water flow in the vadose zone. Although the soil water content and particle composition were moderately variable, no significant differences were observed in recharge rates among the five sites (p > 0.05) owing to the identical climate and land use. The recharge rates did not show a significant difference (p > 0.05) between different tracers' methods. However, recharge estimates by the chloride mass balance method indicated higher variations (23.5 %) than those by the peak depth method (11.2 % to 18.7 %) among five sites. Moreover, if considering the contribution of immobile water in vadose zone, groundwater recharge would be overestimated (25.4 % to 37.8 %) using the peak depth method. This study provides a favourable reference for accurate groundwater recharge and its variation evaluated using different tracers' methods in deep vadose zone.

Evaluation of Groundwater Flow Changes Associated with Drainage within Multilayer Aquifers in a Semiarid Area

In order to evaluate the impact of groundwater drainage on groundwater flow, the Hetaoyu coal field was taken as a case study in the Longdong area, China, where the coal seam was covered with multilayer aquifers. A three-dimensional unsteady groundwater flow model and a one-dimensional fracture water flow model were calculated by joint equations for changing hydrogeological structures under coal mining. According to the results, mine construction had greatly affected groundwater reserves in the Quaternary phreatic aquifer, Cretaceous Huanhe confined aquifer, and Luohe confined aquifer. The groundwater drainage was mainly from the Cretaceous aquifer, in which the aquifer reserves of the Luohe Formation decreased by 30,861.8 m3/m, accounting for about 92% of the total changes in local groundwater reserves. A drop funnel with an area of about 2.3 km2 would be formed under the groundwater discharge of 187.6 m3/h for the main inclined shaft excavation of the Hetaoyu coal mine. With the continuation of mining activities, the mine water flow will reach 806.83 m3/h and would result in descending funnel area of about 4.5 km2, the groundwater level drawdown at least 16 m, which would exceed the limited value regulated by the government. Therefore, in order to ensure the safety of coal mining and protect groundwater resources, the Hetaoyu Coal Mine departments should take some water loss prevention and control projects to reduce the drawdown of groundwater.

Understanding the key factors that influence soil moisture estimation using the unscented weighted ensemble Kalman filter

Accurate quantification of soil moisture contributes significantly to an understanding of land surface processes. In-situ observable soil moisture data are often sparsely distributed, and model performance is influenced by many factors. In this study, 14 numerical experimental schemes about the effects of uncertainties in multiple factors (soil property, time step, assimilation interval, precipitation, soil layer thickness and initial value) on soil moisture estimation were evaluated based on the unscented weighted ensemble Kalman filter (UWEnKF) and a one-dimensional vertical water flow model at the ELBARA field site in the Maqu monitoring network in the upper reaches of the Yellow River, China. The experiments showed that soil properties had little effect on model parameters (e.g., saturated soil moisture content, saturated soil hydraulic conductivity, saturated soil matric potential) in either the horizontal or vertical direction using the model numerical solving scheme adopted, and thus had little effect on soil moisture estimation. Using only the observed Ksatmay lead to better soil moisture predictions. Reducing the simulation time step has limited impact on soil moisture estimation. The effects of precipitation on soil moisture estimations varied due to overestimation or underestimation of soil moisture content in different soil layers, and differences in soil layer thicknesses led to uncertainty in soil moisture estimation. The model accurately predicted the change trend of soil moisture if the initial values were reasonable. UWEnKF performed well in terms of improving soil moisture estimations despite the uncertainty of many factors in data assimilation system, and performed better with high assimilation frequency (i.e., small assimilation interval). Thus, UWEnKF is an effective and practical technique for soil moisture assimilation whatever the uncertainty of multiple factors is.

Promise and pitfalls of modeling grassland soil moisture in a free-air CO2 enrichment experiment (BioCON) using the SHAW model

Free-air carbon dioxide (CO2) enrichment (FACE) experiments provide an opportunity to test models of heat and water flow under novel, controlled situations and eventually allow use of these models for hypothesis evaluation. This study assesses whether the United States Department of Agriculture SHAW (Simultaneous Heat and Water) numerical model of vertical one-dimensional soil water flow across the soil-plant-atmosphere continuum is able to adequately represent and explain the effects of increasing atmospheric CO2 on soil moisture dynamics in temperate grasslands. Observations in a FACE experiment, the BioCON (Biodiversity, CO2, and Nitrogen) experiment, in Minnesota, USA, were compared with results of vertical soil moisture distribution. Three scenarios represented by different plots were assessed: bare, vegetated with ambient CO2, and similarly vegetated with high CO2. From the simulations, the bare plot soil was generally the wettest, followed by a drier high-CO2 vegetated plot, and the ambient CO2 plot was the driest. The SHAW simulations adequately reproduced the expected behavior and showed that vegetation and atmospheric CO2 concentration significantly affected soil moisture dynamics. The differences in modeled soil moisture amongst the plots were largely due to transpiration, which was low with high CO2. However, the modeled soil moisture only modestly reproduced the observations. Thus, while SHAW is able to replicate and help broadly explain soil moisture dynamics in a FACE experiment, its application for point- and time-specific simulations of soil moisture needs further scrutiny. The typical design of a FACE experiment makes the experimental observations challenging to model with a one-dimensional distributed model. In addition, FACE instrumentation and monitoring will need improvement in order to be a useful platform for robust model testing. Only after this can we recommend that models such as SHAW are adequate for process interpretation of datasets from FACE experiments or for hypothesis testing.

Algebraic model for one-dimensional horizontal water flow with arbitrary initial soil water content

A simple analytical solution of the equation for the one-dimensional horizontal permeability of soil water is important for estimating the hydraulic properties of soil. Our main objective was to develop analytical solutions to the nonlinear Richards equation, with constant-saturation upper boundary and an arbitrary initial soil water content (SWC) for horizontal absorption. We estimated the infiltration rate based on the hypothesis proposed by Parlange and carried out a series of transformations based on the Brooks–Corey model to obtain a theoretical function of the one-dimensional movement of water in unsaturated soil under an arbitrary initial SWC. The algebraic analytical solutions were simple, and the selection of the initial SWC was arbitrary. We assumed three scenarios of linear distributions of initial SWC, and Hydrus-1D software was used to simulate horizontal infiltration. Based on the comparison of algebraic and numerical results, the corrected algebraic model was proposed and verified by the arbitrary initial water content conditions when the maximum SWC was less than the half of saturated water content. The proposed method provides a description of horizontal infiltration for the heterogeneous initial SWCs.

A User-Friendly Tool to Characterize the Moisture Transfer in Porous Building Materials: FLoW1D

This paper presents a user-friendly tool—FLoW1D (One-Dimensional Water Flow)—for the estimation of parameters that characterize the unsaturated moisture transfer in porous building materials. FLoW1D has been developed in Visual Basic for Applications and implemented as a function of the well-known Microsoft Excel© spreadsheet application. The aim of our work is to provide a simple and useful tool to improve the analysis and interpretation of conventional tests for the characterization of the hygric behavior of porous building materials. FLoW1D embraces the conceptual model described in EN 15026 for moisture transfer in building elements, and its implementation has been verified and validated correctly. In order to show the scope of the code, an example of an application has been presented. The hygric characterization of the limestone that is mostly employed in the Cathedral of Santa Maria and San Julian in Cuenca (Spain) was conducted based on an analysis of the conventional water absorption by capillarity tests (EN 15801).

Choice of fiber-reinforced base material to reduce internal erosion mass transport

This paper aims to investigate the reduction of the internal erosion by inclusion of fiber in the context of the base sandy soil next to the filter. Two samples overlain by a gravel filter, and with different grain sizes, (i.e., a poorly graded sand, and a poorly graded sand with clay) were used in this study. The specimens with various relative densities were exposed to one-dimensional water flow under 1 bar pressure, and erosion of the base soils without reinforcement along with fiber-reinforced soils through the coarse grain filter was measured. Polypropylene fiber content was adjusted to 0.50, 0.75, and 1.0% by weight of the base soils. The mass of the soil clogged in the filter plus the ones suspended in the water were quantified to determine mass of internal erosion for each specimen. The results indicated that internal erosion and permeability decrease with increase in fiber reinforcement and relative density. In addition, reinforcing sands without or with fines could change their erosion category from some-erosion to no-erosion and from excessive-erosion to some-erosion respectively.

Open Water Flow in a Wet/Dry Multiply-Connected Channel Network: A Robust Numerical Modeling Algorithm

Our goal was to develop a robust algorithm for numerical simulation of one-dimensional shallow water flow in a complex multiply-connected channel network with arbitrary geometry and variable topography. We apply a central-upwind scheme with a novel reconstruction of the open water surface in partially flooded cells that does not require additional correction. The proposed reconstruction and an exact integration of source terms for the momentum conservation equation provide positivity preserving and well-balanced features of the scheme for various wet/dry states. We use two models based on the continuity equation and mass and momentum conservation equations integrated for a control volume around the channel junction to its treatment. These junction models permit to simulate subcritical and supercritical flows in a channel network. Numerous numerical experiments demonstrate the robustness of the proposed numerical algorithm and a good agreement of numerical results with exact solutions, experimental data, and results of the previous numerical studies. The proposed new specialized test on inundation and drying of an initially dry channel network shows the merits of the new numerical algorithm to simulate the subcritical/supercritical open water flows in the networks.

A comprehensive quasi-3-D model for regional-scale unsaturated–saturated water flow

Abstract. For computationally efficient modeling of unsaturated–saturated flow in regional scales, the quasi-three-dimensional (3-D) scheme that considers one-dimensional (1-D) soil water flow and 3-D groundwater flow is an alternative method. However, it is still practically challenging for regional-scale problems due to the highly nonlinear and intensive input data needed for soil water modeling and the reliability of the coupling scheme. This study developed a new quasi-3-D model coupled to the UBMOD 1-D soil water balance model with the MODFLOW 3-D hydrodynamic model. A new implementation method of the iterative scheme was developed in which the vertical net recharge and unsaturated zone depth were used as the exchange information. A modeling framework was developed to organize the coupling scheme of the soil water model and the groundwater model and to handle the pre- and post-processing information. The strength and weakness of the coupled model were evaluated by using two published studies. The comparison results show that the coupled model is satisfactory in terms of computational accuracy and mass balance error. The influences of spatial and temporal discretization as well as the stress period on the model accuracy were discussed. Additionally, the coupled model was used to evaluate groundwater recharge in a real-world study. The measured groundwater table and soil water content were used to calibrate the model parameters, and the groundwater recharge data from a 2-year tracer experiment were used to evaluate the recharge estimation. The field application further shows the practicability of the model. The developed model and the modeling framework provide a convenient and flexible tool for evaluating unsaturated–saturated flow systems at the regional scale.

Analytical Solutions for One-Dimensional Water Flow in Vegetated Layered Soil

AbstractVegetation reduces soil pore-water pressure (PWP) through root water uptake. There are limited studies about the effects of vegetation on PWP distributions in layered soil, such as multilay...

Influences of thermal dispersion on soil water flux estimates using heat pulse technique in saturated soils

The heat-pulse technique (HPT) shows good potentials for in situ determinations of soil water flux (J), but its applications are limited because of J underestimates. This study aims to experimentally investigate the influences of thermal dispersion on J estimates using HPT in packed sand, silt loam, and sandy clay loam with one-dimensional saturated water flow, hypothesizing that J underestimates are caused by neglecting heat dispersion in heat transport model that arises from the heterogeneity of water velocities within and between water-filled soil pores. The results indicated that J estimates exhibited good linearity with the measurements (R2 > 0.95). However, they were biased toward underestimates. The thermal dispersion's dependence on J was described by a power function. When heat dispersion was considered in the traditional heat conduction–advection model, the traditional ratio method yielded a higher accuracy with relative errors reduced by 45.0–74.3%, the bias reduced by 47.1–74.0% and the root mean square error reduced by 48.0–68.8%. In terms of the range of J herein, the maximum Keith Jirka Jan (KJJ) numbers obtained were 6.8%, 10.4%, and 13.4% for sand, silt loam, and sandy clay loam, respectively. Moreover, their corresponding J thresholds were 41.7, 21.1, and 12.3 μm s−1, respectively.

1-D coupled non-equilibrium sediment transport modeling for unsteady flows in the discontinuous Galerkin framework

A high-resolution, 1-D numerical model has been developed in the discontinuous Galerkin framework to simulate 1-D flow behavior, sediment transport, and morphological evaluation under unsteady flow conditions. The flow and sediment concentration variables are computed based on the one-dimensional shallow water flow equations, while empirical equations are used for entrainment and deposition processes. The sediment transport model includes the bed load and suspended load components. New formulations for Harten-Lax-van Leer (HLL) and Harten-Lax-van Contact (HLLC) are presented for shallow water flow equations that include the bed load and suspended load fluxes. The computational results for the flow and morphological changes after two dam break events are compared with the physical model tests. Results show that the modified HLL and HLLC formulations are robust and can accurately predict morphological changes in highly unsteady flows.

Numerical simulation of bare soil water and heat flow under an automated irrigation system

Modern irrigation techniques use automated systems where irrigation schedules are controlled according to certain criteria. The objective of this study is to numerically estimate irrigation events, water content and temperature distributions, evaporation, drainage, and soil water under closed loop automated irrigation systems of a bare soil. The automated irrigation system is activated and deactivated according to the water content value. The governing equations for transient one-dimensional liquid water flow and heat transfer of unsaturated porous media are applied. The energy balance equation at the soil surface is used as an upper boundary condition based on measured meteorological data of Jeddah City. The results show that the current procedure can be applied to simulate different variables under automated irrigation systems. The water content shows periodic behavior, as well as time lags and decreases in amplitude with soil depth. The timing of applied irrigation has an important impact on evaporation and soil temperature. Applying irrigation water during the daytime leads to increased evaporation. The soil surface temperature decreases suddenly when water is supplied in the afternoon, while a slight increase is observed when irrigation is applied at midnight.

Simulating coupled surface and subsurface water flow in a tile-drained agricultural catchment

Summary The impact of shallow tile drainage networks on groundwater flow patterns, and associated transport of chemical species or sediment particles, needs to be quantified to evaluate the effects of agricultural management on water resources. A current challenge is to represent tile drainage networks in numerical models at the scale of a catchment for which proper simulation and reproduction of subsurface drainage water dynamics are essential. This study investigates the applicability of various tile drainage modeling concepts by comparing their results to a reference model. The models were setup for a 3.5 ha regularly monitored tile-drained area located in the clayey till Lillebaek catchment in Denmark, where the main input of water to the streams originates from subsurface drainage. Several simulations helped identify the most efficient way of modeling tile-drained areas using the integrated surface water and groundwater HydroGeoSphere code, which also simulates one-dimensional water flow in tile drains. The aim was also to provide insight on the design of larger scale models of complex tile drainage systems, for which computational time can become very large. A reference model that simulated coupled surface flow, groundwater flow and flow in tile drains was setup and showed a rapid response in drain outflow when precipitation is applied. A series of additional simulations were performed to test the influence of flow boundary conditions, temporal resolution of precipitation data, conceptual representations of clay tills and drains, as well as spatial discretization of the mesh. For larger scale models, the simulations suggest that a simplification of the geometry of the drainage network is a suitable option for avoiding highly discretized meshes. Representing the drainage network by a high-conductivity porous medium layer reproduces outflow simulated by the reference model. This approach greatly reduces the mesh complexity and simulation time and thus represents an alternative to a discrete representation of drains at the field scale, but specifying the hydraulic properties of the layer requires calibration against observed drain discharge.

Assessment of factors influencing groundwater-level change using groundwater flow simulation, considering vertical infiltration from rice-planted and crop-rotated paddy fields in Japan

Assessing factors that influence groundwater levels such as land use and pumping strategy, is essential to adequately manage groundwater resources. A transient numerical model for groundwater flow with infiltration was developed for the Tedori River alluvial fan (140 km2), Japan. The main water input into the groundwater body in this area is irrigation water, which is significantly influenced by land use, namely paddy and upland fields. The proposed model consists of two models, a one-dimensional (1-D) unsaturated-zone water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Numerical simulation of groundwater flow from October 1975 to November 2009 was performed to validate the model. Simulation revealed seasonal groundwater level fluctuations, affected by paddy irrigation management. However, computational accuracy was limited by the spatiotemporal data resolution of the groundwater use. Both annual groundwater levels and recharge during the irrigation periods from 1975 to 2009 showed long-term decreasing trends. With the decline in rice-planted paddy field area, groundwater recharge cumulatively decreased to 61 % of the peak in 1977. A paddy-upland crop-rotation system could decrease groundwater recharge to 73–98 % relative to no crop rotation.

Tree species and diversity effects on soil water seepage in a tropical plantation

Plant diversity has been shown to influence the water cycle of forest ecosystems by differences in water consumption and the associated effects on groundwater recharge. However, the effects of biodiversity on soil water fluxes remain poorly understood for native tree species plantations in the tropics. Therefore, we estimated soil water fluxes and assessed the effects of tree species and diversity on these fluxes in an experimental native tree species plantation in Sardinilla (Panama). The study was conducted during the wet season 2008 on plots of monocultures and mixtures of three or six tree species. Rainfall and soil water content were measured and evapotranspiration was estimated with the Penman-Monteith equation. Soil water fluxes were estimated using a simple soil water budget model considering water input, output, and soil water and groundwater storage changes and in addition, were simulated using the physically based one-dimensional water flow model Hydrus-1D.In general, the Hydrus simulation did not reflect the observed pressure heads, in that modeled pressure heads were higher compared to measured ones. On the other hand, the results of the water balance equation (WBE) reproduced observed water use patterns well. In monocultures, the downward fluxes through the 200cm-depth plane were highest below Hura crepitans (6.13mmday−1) and lowest below Luehea seemannii (5.18mmday−1). The average seepage rate in monocultures (±SE) was 5.66±0.18mmday−1, and therefore, significantly higher than below six-species mixtures (5.49±0.04mmday−1) according to overyielding analyses. The three-species mixtures had an average seepage rate of 5.63±0.12mmday−1 and their values did not differ significantly from the average values of the corresponding species in monocultures. Seepage rates were driven by the transpiration of the varying biomass among the plots (r=0.61, p=0.017). Thus, a mixture of trees with different growth rates resulted in moderate seepage rates compared to monocultures of either fast growing or slow growing tree species. Our results demonstrate that tree-species specific biomass production and tree diversity are important controls of seepage rates in the Sardinilla plantation during the wet season.

Modeling local control effects on the temporal stability of soil water content

Summary Occurrence of temporal stability of soil water content has been observed for a range of soil and landscape conditions and is generally explained as a consequence of local and non-local controls. However, the underlying factors for this phenomenon are not completely understood and have not been quantified. This work attempts to elucidate and quantify the effects of several local controls, such as soil hydraulic properties and root water uptake, through water flow simulations. One-dimensional water flow was simulated with the HYDRUS code for bare and grassed sandy loam, loam and clay soils at different levels of variability in the saturated hydraulic conductivity Ksat. Soil water content at 0.05 and 0.60 m and the average water content of the top 1 m were analyzed. Temporal stability was characterized by calculating the mean relative differences of soil water content in 100 soil columns used for each combination of soil and season. Using log-normal distributions of Ksat resulted in mean relative differences distributions that were commonly observed in experimental studies of soil water content variability. Linear relationships were observed between scaling factor of ln Ksat and spread of the mean relative differences distributions. For the same scaling factor and soil texture, simulated shapes of the mean relative differences distributions depended on the duration of the simulation period and the season. Variation in mean relative differences was higher in coarser textures than in finer ones and more variability was seen in the topsoil than in the subsoil. Root water uptake decreased the mean relative differences variability in the root zone and increased variability below it. This work presents a preliminary research to promote the use of water flow simulations under site-specific conditions to better understand the temporal stability of soil water contents. The estimation of the spatial variability of Ksat from soil water content monitoring presents an interesting avenue for further research.