Effects of compaction on soil hydraulic properties, penetration resistance and water flow patterns at the soil profile scale

2019 ◽  
Vol 35 (3) ◽  
pp. 367-377 ◽  
Author(s):  
Mona Mossadeghi‐Björklund ◽  
Nicholas Jarvis ◽  
Mats Larsbo ◽  
Johannes Forkman ◽  
Thomas Keller
Keyword(s):  
Water Flow ◽  
Soil Profile ◽  
Hydraulic Properties ◽  
Penetration Resistance ◽  
Flow Patterns ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

scholarly journals Comparison between field measurements and numerical simulation of steady-state solute transport in a heterogeneous soil profile

1997 ◽  
Vol 1 (4) ◽  
pp. 853-871 ◽  
Author(s):  
J. Vanderborght ◽  
D. Jacques ◽  
D. Mallants ◽  
P.-H. Tseng ◽  
J. Feyen
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Random Fields ◽  
Hydraulic Properties ◽  
Soil Hydraulic Properties ◽  
Field Scale ◽  
Flow Heterogeneity ◽  
Heterogeneous Soil ◽  
Soil Hydraulic ◽  
Second Procedure

Abstract. Abstract: Field-scale solute dispersion is determined by water flow heterogeneity which results from spatial variability of soil hydraulic properties and soil moisture state. Measured variabilities of soil hydraulic properties are highly sensitive to the experimental method. Field-scale dispersion derived from leaching experiments in a macroporous loam soil was compared with field-scale dispersion obtained with numerical simulations in heterogeneous random fields. Four types of random fields of hydraulic properties having statistical properties derived from four different types of laboratory measurements were considered. Based on this comparison, the measurement method depicting heterogeneities of hydraulic properties most relevant to field-scale solute transport was identified. For unsaturated flow, the variability of the hydraulic conductivity characteristic measured on a small soil volume was the most relevant parameter. For saturated flow, simulated dispersion underestimated the measured dispersion and it was concluded that heterogeneity of macroscopic hydraulic properties could not represent solute flow heterogeneity under these flow conditions. Field-scale averaged solute concentrations depend both on the detection method and the averaging procedure. Flux-averaged concentrations (relevant to practical applications) differ from volume-averaged or resident concentrations (easy to measure), especially when water flow is more heterogeneous. Simulated flux and resident concentrations were subsequently used to test two simple one-dimensional transport models in predicting flux concentrations when they are calibrated on resident concentrations. In the first procedure, solute transport in a heterogeneous soil is represented by a 1-D convection dispersion process. The second procedure was based on the relation between flux and resident concentrations for a stochastic convective process. Better predictions of flux concentrations were obtained using the second procedure, especially when water flow and solute transport are very heterogeneous.

scholarly journals A modified hood infiltrometer to estimate the soil hydraulic properties from the transient water flow measurements

2015 ◽  
Vol 530 ◽  
pp. 554-560 ◽  
Author(s):  
D. Moret-Fernández ◽  
C. González-Cebollada ◽  
B. Latorre ◽  
V. Pérez
Keyword(s):  
Water Flow ◽  
Hydraulic Properties ◽  
Soil Hydraulic Properties ◽  
Flow Measurements ◽  
Soil Hydraulic

Ant burrow effects on water flow and soil hydraulic properties of Sparta sand

1996 ◽  
Vol 37 (2-3) ◽  
pp. 83-93 ◽  
Author(s):  
D. Wang ◽  
B. Lowery ◽  
J.M. Norman ◽  
K. McSweeney
Keyword(s):  
Water Flow ◽  
Hydraulic Properties ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

scholarly journals Scale-dependency and spatial variability of soil hydraulic properties

2004 ◽  
Author(s):  
Renduo Zhang ◽  
David Russo
Keyword(s):  
Spatial Variability ◽  
Water Flow ◽  
Hydraulic Properties ◽  
Small Scale ◽  
Scale Dependency ◽  
Soil Hydraulic Properties ◽  
Field Scale ◽  
Essential Information ◽  
Lab Experiments ◽  
Soil Hydraulic

Water resources assessment and protection requires quantitative descriptions of field-scale water flow and contaminant transport through the subsurface, which, in turn, require reliable information about soil hydraulic properties. However, much is still unknown concerning hydraulic properties and flow behavior in heterogeneous soils. Especially, relationships of hydraulic properties changing with measured scales are poorly understood. Soil hydraulic properties are usually measured at a small scale and used for quantifying flow and transport in large scales, which causes misleading results. Therefore, determination of scale-dependent and spatial variability of soil hydraulic properties provides the essential information for quantifying water flow and chemical transport through the subsurface, which are the key processes for detection of potential agricultural/industrial contaminants, reduction of agricultural chemical movement, improvement of soil and water quality, and increase of agricultural productivity. The original research objectives of this project were: 1. to measure soil hydraulic properties at different locations and different scales at large fields; 2. to develop scale-dependent relationships of soil hydraulic properties; and 3. to determine spatial variability and heterogeneity of soil hydraulic properties as a function of measurement scales. The US investigators conducted field and lab experiments to measure soil hydraulic properties at different locations and different scales. Based on the field and lab experiments, a well-structured database of soil physical and hydraulic properties was developed. The database was used to study scale-dependency, spatial variability, and heterogeneity of soil hydraulic properties. An improved method was developed for calculating hydraulic properties based on infiltration data from the disc infiltrometer. Compared with the other methods, the proposed method provided more accurate and stable estimations of the hydraulic conductivity and macroscopic capillary length, using infiltration data collected atshort experiment periods. We also developed scale-dependent relationships of soil hydraulic properties using the fractal and geostatistical characterization. The research effort of the Israeli research team concentrates on tasks along the second objective. The main accomplishment of this effort is that we succeed to derive first-order, upscaled (block effective) conductivity tensor, K'ᵢⱼ, and time-dependent dispersion tensor, D'ᵢⱼ, i,j=1,2,3, for steady-state flow in three-dimensional, partially saturated, heterogeneous formations, for length-scales comparable with those of the formation heterogeneity. Numerical simulations designed to test the applicability of the upscaling methodology to more general situations involving complex, transient flow regimes originating from periodic rain/irrigation events and water uptake by plant roots suggested that even in this complicated case, the upscaling methodology essentially compensated for the loss of sub-grid-scale variations of the velocity field caused by coarse discretization of the flow domain. These results have significant implications with respect to the development of field-scale solute transport models capable of simulating complex real-world scenarios in the subsurface, and, in turn, are essential for the assessment of the threat posed by contamination from agricultural and/or industrial sources.  

scholarly journals Inverse modelling for predicting both water and nitrate movement in a structured-clay soil (Red Ferrosol)

PeerJ ◽  
2019 ◽  
Vol 6 ◽  
pp. e6002 ◽  
Author(s):  
James M. Kirkham ◽  
Christopher J. Smith ◽  
Richard B. Doyle ◽  
Philip H. Brown
Keyword(s):  
Adsorption Isotherm ◽  
Solute Transport ◽  
Water Flow ◽  
Hydraulic Properties ◽  
Transport Processes ◽  
Inverse Modelling ◽  
Diffusion Experiment ◽  
Soil Hydraulic Properties ◽  
Soil Columns ◽  
Soil Hydraulic

Soil physical parameter calculation by inverse modelling provides an indirect way of estimating the unsaturated hydraulic properties of soils. However many measurements are needed to provide sufficient data to determine unknown parameters. The objective of this research was to assess the use of unsaturated water flow and solute transport experiments, in horizontal packed soil columns, to estimate the parameters that govern water flow and solute transport. The derived parameters are then used to predict water infiltration and solute migration in a repacked soil wedge. Horizontal columns packed with Red Ferrosol were used in a nitrate diffusion experiment to estimate either three or six parameters of the van Genuchten–Mualem equation while keeping residual and saturated water content, and saturated hydraulic conductivity fixed to independently measured values. These parameters were calculated using the inverse optimisation routines in Hydrus 1D. Nitrate concentrations measured along the horizontal soil columns were used to independently determine the Langmuir adsorption isotherm. The soil hydraulic properties described by the van Genuchten–Mualem equation, and the NO3–adsorption isotherm, were then used to predict water and NO3–distributions from a point-source in two 3D flow scenarios. The use of horizontal columns of repacked soil and inverse modelling to quantify the soil water retention curve was found to be a simple and effective method for determining soil hydraulic properties of Red Ferrosols. These generated parameters supported subsequent testing of interactive flow and reactive transport processes under dynamic flow conditions.

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