High-Resolution Pore-Scale Water Content Measurement in a Translucent Soil Profile from Light Transmission

HighlightsResearch methods are needed to study preferential flow processes at pore scale and high temporal resolution.Novel verification of the light transmission method shows high efficiency to measure rapid transient soil water flow.Recast of a previous physical model allows reliable pore-scale water content quantification in translucent soil profiles.Insights from the light transmission method can inform preferential flow modeling efforts.Abstract. Understanding rapid transient flows in the soil unsaturated zone continues to be a major challenge in hydrology and water quality engineering. For example, surface runoff mitigation by riparian buffers can be limited by rapid transient flows due to the natural propensity of these areas for preferential flow pathways (i.e., caused by roots, wormholes, or wetting/drying cycles). However, current monitoring technologies are limited in their ability to capture rapid soil preferential flows at high spatial and temporal resolutions. Among the state-of-the-art technologies to monitor preferential flow, the light transmission method (LTM) has become a promising tool to quantify pore-scale water contents at a laboratory scale, but its reliability and consistency need further study. The objectives of this study are to recast a previously developed LTM physical model, propose a novel verification method to assess LTM reliability to measure pore-scale water dynamics in laboratory translucent soil profiles, and identify the representative pore radius of translucent soil profiles based on their average number of pores. This study found a high measuring efficiency with LTM for soil moisture and drainage estimations (NSE > 0.98, RMSE < 5.4%), showing its potential for use in laboratory analysis of pore-scale rapid transient water dynamics typically found in preferential flow through the vadose zone. This study also shows that the parameter traditionally associated with the number of pores in a translucent soil profile is a fitting parameter with no direct physical meaning. Keywords: Beer-Lambert law, Fresnel law, Light transmission method, Preferential flow, Riparian buffer, Vadose zone.

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Supplemental information for "High-resolution Pore-scale Water Content Measurement in a Translucent Soil Profile from Light Transmission"

10.13031/14442632.v1 ◽

2021 ◽

Author(s):

Enrique Orozco López ◽

Rafael Muñoz-Carpena ◽

Bin Gao ◽

Garey A. Fox

Keyword(s):

High Resolution ◽

Water Content ◽

Soil Profile ◽

Light Transmission ◽

Pore Scale ◽

Matlab Code ◽

Content Measurement

Three MATLAB code files used in the development of the article "High-Resolution Pore-Scale Water Content Measurement in a Translucent Soil Profile from Light Transmission." In addition, examples of the datasets required to compute the above mentioned code are provided, including images and spreadsheets.

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Supplemental information for "High-resolution Pore-scale Water Content Measurement in a Translucent Soil Profile from Light Transmission"

10.13031/14442632 ◽

2021 ◽

Author(s):

Enrique Orozco López ◽

Rafael Muñoz-Carpena ◽

Bin Gao ◽

Garey A. Fox

Keyword(s):

High Resolution ◽

Water Content ◽

Soil Profile ◽

Light Transmission ◽

Pore Scale ◽

Matlab Code ◽

Content Measurement

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Influence of the shape of inter-horizon boundary and size of soil tongues on preferential flow under shallow groundwater conditions: A simulation study

Canadian Journal of Soil Science ◽

10.4141/cjss10079 ◽

2011 ◽

Vol 91 (2) ◽

pp. 211-221 ◽

Cited By ~ 5

Author(s):

Priyantha B. Kulasekera ◽

Gary W. Parkin

Keyword(s):

Solute Transport ◽

Vadose Zone ◽

Simulation Study ◽

Soil Profile ◽

Preferential Flow ◽

Shallow Groundwater ◽

Soil Horizon ◽

Tongue Length ◽

The Impact ◽

Water And Solute Transport

Kulasekera, P. B. and Parkin, G. W. 2011. Influence of the shape of inter-horizon boundary and size of soil tongues on preferential flow under shallow groundwater conditions: A simulation study. Can. J. Soil Sci. 91: 211–221. Detailed studies of the impact of soil tongues at soil horizon interfaces are very important in understanding preferential flow processes through layered soils and in improving the accuracy of models predicting water and solute transport through the vadose zone. The implication of having soil tongues of different shapes and sizes created at the soil horizon interface on solute transport through a layered soil horizon was studied by simulating water and solute transport using the VS2DI model. This 2-D simulation study reconfirmed that soil tongues facilitate preferential flow, and the level of activeness of tongues may depend on the number of soil tongues, their spacing and distribution. Also, the size of the soil tongues (length and diameter at the interface between the soil horizons) and their shape influence the rate of preferential flow. Increasing tongue length consistently resulted in an increase in solute velocity across the entire soil profile regardless of the tongue shape; for example, a soil tongue of 0.25 m length increased solute velocity by about 1.5 times over a soil profile without tongues, but this increase might be different for soil types and groundwater conditions other than those considered in this study. Narrowing of tongues increased solute velocity, whereas increasing the number of tongues in a wider soil profile decreased the solute-front's velocity. As tongue length increased, the area containing solutes at prescribed elapsed times decreased. An implication of this study is that soil horizon tongue shape and spacing reduce pollutant residence times, hence inter-horizon boundary morphology should be considered when modelling transport through the vadose zone. As well, since the solute velocity behaviours of a triangular- and a wider rectangular-shaped tongue were nearly identical, simply measuring solute velocity in the field will reveal little information on the shape of a soil tongue.

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Impacts of grass removal on wetting and actual water repellency in a sandy soil

Journal of Hydrology and Hydromechanics ◽

10.1515/johh-2016-0053 ◽

2017 ◽

Vol 65 (1) ◽

pp. 88-98 ◽

Cited By ~ 6

Author(s):

Klaas Oostindie ◽

Louis W. Dekker ◽

Jan G. Wesseling ◽

Violette Geissen ◽

Coen J. Ritsema

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Profile ◽

Water Repellency ◽

Bare Soil ◽

Soil Profiles ◽

The Impact ◽

Water Contents ◽

Soil Water Contents

Abstract Soil water content and actual water repellency were assessed for soil profiles at two sites in a bare and grasscovered plot of a sand pasture, to investigate the impact of the grass removal on both properties. The soil of the plots was sampled six times in vertical transects to a depth of 33 cm between 23 May and 7 October 2002. On each sampling date the soil water contents were measured and the persistence of actual water repellency was determined of field-moist samples. Considerably higher soil water contents were found in the bare versus the grass-covered plots. These alterations are caused by differences between evaporation and transpiration rates across the plots. Noteworthy are the often excessive differences in soil water content at depths of 10 to 30 cm between the bare and grass-covered plots. These differences are a consequence of water uptake by the roots in the grass-covered plots. The water storage in the upper 19 cm of the bare soil was at least two times greater than in the grass-covered soil during dry periods. A major part of the soil profile in the grass-covered plots exhibited extreme water repellency to a depth of 19 cm on all sampling dates, while the soil profile of the bare plots was completely wettable on eight of the twelve sampling dates. Significant differences in persistence of actual water repellency were found between the grass-covered and bare plots.

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Improved light-transmission method for the study of LNAPL migration and distribution rule

Water Science & Technology ◽

10.2166/wst.2015.141 ◽

2015 ◽

Vol 71 (10) ◽

pp. 1576-1585 ◽

Cited By ~ 3

Author(s):

Yongsheng Zhao ◽

Jiaqiang Sun ◽

Chao Sun ◽

Jian Cui ◽

Rui Zhou

Keyword(s):

Image Processing ◽

Moisture Content ◽

Transition Zone ◽

Vadose Zone ◽

Light Transmission ◽

Processing Method ◽

Transmission Method ◽

Image Processing Method ◽

Distribution Rule ◽

Capillary Zone

In this study, diesel was selected as a pollutant to study the migration and distribution rule of light non-aqueous phase liquid (LNAPL) in the simulated vadose zone. Saturation was regarded as a critical parameter to reflect the LNAPL migration and distribution rule. To get LNAPL saturation distribution figures, an image processing method of saturation was established to improve light-transmission technology, which can deal with digital camera images. Results showed that the vadose zone contains three areas from top to bottom, named dry media, transition zone and capillary zone. The system has two interfaces at which moisture content increased significantly. The significant increase in moisture content induced two apparent horizontal LNAPL diffusions in the two interfaces. Furthermore, the highly saturated LNAPL was mostly distributed near the wet interface, which lay between the dry media and the transition zone. Moreover, the downstream expansion of LNAPL in the capillary zone was promoted by groundwater flow, yet cutting off LNAPL supply could stop the downstream expansion after a period of time. The accuracy of this image processing method of saturation was verified by mass balance theory and reported a relative error of 4.38%.

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Preferential Flow Systems Amended with Biogeochemical Components: Imaging of a Two-Dimensional Study

10.5194/hess-2017-486 ◽

2017 ◽

Author(s):

Ashley R. Pales ◽

Biting Li ◽

Heather M. Clifford ◽

Shyla Kupis ◽

Nimisha Edayilam ◽

...

Keyword(s):

Porous Media ◽

Preferential Flow ◽

Light Transmission ◽

Water Saturation ◽

Silica Sand ◽

Two Dimensional ◽

Unstable Flow ◽

Transmission Method ◽

Soil Component ◽

Plant Exudates

Abstract. The vadose zone is a highly interactive heterogeneous system through which water enters into the subsurface system by infiltration. This paper details the effects of simulated plant exudate and soil component solutions upon unstable flow patterns in a porous media (ASTM silica sand; US Silica, Ottawa, IL, USA) through the use of two-dimensional (2D) tank light transmission method (LTM). The contact angle and surface tension of two simulated plant exudate solutions (i.e. oxalate, and citrate) and two soil component solutions (i.e. tannic acid, and Suwannee River Natural Organic Matter) were analyzed to determine the liquid-gas and liquid-solid interface characteristics of each. To determine if the unstable flow formations were dependent on the type and concentration of the simulated plant exudates and soil components, the analysis of the effects of the simulated plant exudate and soil component solutions were compared to a control rainwater solution. The differences in the fingering flow were quantified with the finger geometries, the velocity of finger propagation, the vertical and horizontal water saturation profiles, and the water saturation at the fingertips. Significant differences in the interface processes indicated a decrease between the control and the plant exudate and soil component solutions tested; specifically, the control at 64.5 θ and 75.75 Nm/m, to the low concentration of citrate at 52.6 θ and 70.8 Nm/m. The changes in finger geometries and velocity of propagation between the control solution and the simulated plant exudate and soil component solutions further demonstrate that the plant exudates increased the wettability and mobility of the solutions during the infiltration process in unsaturated porous media.

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Preferential water flow in a glacial till soil

Hydrology Research ◽

10.2166/nh.2005.0001 ◽

2005 ◽

Vol 36 (1) ◽

pp. 1-11 ◽

Cited By ~ 19

Author(s):

Christer Jansson ◽

Bengt Espeby ◽

Per-Erik Jansson

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Flow ◽

Preferential Flow ◽

Glacial Till ◽

Water Dynamics ◽

Water Retention Curve ◽

Major Interest ◽

Preferential Water

Measured and simulated response of runoff during snowmelt has suggested that preferential water flow occurs as part of the infiltration process in glacial till. However, only a few quantitative studies have been presented. TDR measurements of soil water content were performed during the growing period in a till slope (7–10%) outside Stockholm. Soil cores were used to determine the water retention curve and the saturated hydraulic conductivity. A physically based one-dimensional model was used to simulate soil water dynamics in the slope. Two simulation approaches were used: a strict one-domain Darcian approach and a two-domain approach accounting for a bypass of the matrix flow system. The measured response of soil water content occurred within the first few hours after rainfall. This was best represented by the two-domain approach, while the response for the one-domain approach was significantly delayed with time and depth. The general behaviour of the soil water content throughout the season was, however, best simulated with a one-domain approach. The results indicated that preferential flow patterns through the unsaturated zone does not need to be considered to describe the seasonal pattern in glacial till soil. However, the results also point out that the purpose of the simulation is decisive when choosing a simulation approach, depending on whether the general soil water content over the season or the instant behaviour immediately after rainfall is of major interest.

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KARAKTERISTIK TANAH DAN PERBANDINGAN PRODUKSI KELAPA SAWIT (Elaeis guineensis Jacq.) DENGAN METODE TANAM LUBANG BESAR DAN PARIT DRAINASE 2:1 PADA LAHAN SPODOSOL DI KABUPATEN BARITO TIMUR PROPINSI KALIMANTAN TENGAH - INDONESIA

Jurnal Pertanian Tropik ◽

10.32734/jpt.v2i2.2897 ◽

2015 ◽

Vol 2 (2) ◽

pp. 148-158

Author(s):

Surianto

Keyword(s):

Soil Texture ◽

Oil Palm ◽

Soil Profile ◽

Chemical Properties ◽

Exchangeable Cations ◽

Soil Horizon ◽

Soil Profiles ◽

Negative Effect ◽

Hole Profile ◽

And Chemical Properties

Spodosol soil of Typic Placorthod sub-group of East Barito District is one of the problem soils with the presence of hardpan layer, low fertility, low water holding capacity, acid reaction and it is not suitable for oil palm cultivation without any properly specific management of land preparation and implemented best agronomic practices. A study was carried out to evaluate the soil characteristic of a big hole (A profile) and no big hole (B profile) system and comparative oil palm productivity among two planting systems. This study was conducted in Spodosol soil at oil palm plantation (coordinate X = 0281843 and Y = 9764116), East Barito District, Central Kalimantan Province on February 2014, by surveying of placic and ortstein depth and observing soil texture and chemical properties of 2 (two) oil palm's soil profiles that have been planted in five years. Big hole system of commercial oil palm field planting on the Spodosol soil area was designed for the specific purpose of minimizing the potential of a negative effect of shallow effective planting depth for oil palms growing due to the hardpan layer (placic and ortstein) presence as deep as 0.25 - 0.50 m. The big hole system is a planting hole type which was vertical-sided with 2.00 m x 1.50 m on top and bottom side and 3.00 m depth meanwhile the 2:1 drain was vertical-sided also with 1.50 m depth and 300 m length. Oil palm production was recorded from the year 2012 up to 2014. Results indicated that the fractions both big hole profile (A profile) and no big hole profile (B profile) were dominated by sands ranged from 60% to 92% and the highest sands content of non-big hole soil profile were found in A and E horizons (92%). Better distribution of sand and clay fractions content in between layers of big hole soil profiles of A profile sample is more uniform compared to the B profile sample. The mechanical holing and material mixing of soil materials of A soil profile among the upper and lower horizons i.e. A, E, B and C horizons before planting that resulted a better distribution of both soil texture (sands and clay) and chemical properties such as acidity value (pH), C-organic, N, C/N ratio, CEC, P-available and Exchangeable Bases. Investigation showed that exchangeable cations (Ca, Mg, K), were very low in soil layers (A profile) and horizons (B profile) investigated. The low exchangeable cations due to highly leached of bases to the lower layers and horizons. Besides, the palm which was planted on the big hole system showed good adaptation and response positively by growing well of tertiary and quaternary roots that the roots were penetrable into deeper rooting zone as much as >1.00 m depth. The roots can grow well and penetrate much deeper in A profile compared to the undisturbed hardpan layer (B profile). The FFB (fresh fruit bunches) production of the non-big hole block was higher than the big hole block for the first three years of production. This might be due to the high variation of monthly rainfall in-between years of observation from 2009 to 2014. Therefore, the hardness of placic and ortstein as unpenetrable agents by roots and water to prevent water loss and retain the water in the rhizosphere especially in the drier weather. In the high rainfall condition, the 2:1 drain to prevent water saturation in the oil palm rhizosphere by moving some water into the drain. Meanwhile, the disturbed soil horizon (big hole area) was drier than un disturbance immediately due to water removal to deeper layers. We concluded that both big hole and 2:1 drain are a suitable technology for Spodosol soil land especially in preparing palms planting to minimize the negative effect of the hardpan layer for oil palm growth.

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Analysis of Soil Water Response to Grass Transpiration

Soil and Water Research ◽

10.17221/6510-swr ◽

2013 ◽

Vol 1 (No. 3) ◽

pp. 85-98

Author(s):

Dohnal Michal ◽

Dušek Jaromír ◽

Vogel Tomáš ◽

Herza Jiří

Keyword(s):

Soil Water ◽

Water Uptake ◽

Preferential Flow ◽

Water Movement ◽

Control Volume ◽

Water Pressure ◽

Lower Boundary ◽

Root Water Uptake ◽

Water Dynamics ◽

Soil Water Dynamics

This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation. The lysimeter system provides a well defined control volume with boundary fluxes measured and soil water pressure continuously monitored. The evapotranspiration intensity is estimated by the Penman-Monteith method and compared with the measured lysimeter soil water loss and the simulated root water uptake. Variably saturated flow of water in the lysimeter is simulated using one-dimensional dual-permeability model based on the numerical solution of the Richards’ equation. The availability of water for the root water uptake is determined by the evaluation of the plant water stress function, integrated in the soil water flow model. Different lower boundary conditions are tested to compare the soil water dynamics inside and outside the lysimeter. Special attention is paid to the possible influence of the preferential flow effects on the lysimeter soil water balance. The adopted modelling approach provides a useful and flexible framework for numerical analysis of soil water dynamics in response to the plant transpiration.

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Revegetation in abandoned quarries with landfill stabilized waste and gravels: water dynamics and plant growth – a case study

10.5194/se-2017-72 ◽

2017 ◽

Author(s):

Cheng-liang Zhang ◽

Jing-jing Feng ◽

Li-ming Rong ◽

Ting-ning Zhao

Keyword(s):

Plant Growth ◽

Water Content ◽

Robinia Pseudoacacia ◽

Water Dynamics ◽

Leaf Water Content ◽

Rock Fragments ◽

Platycladus Orientalis ◽

Concrete Production ◽

Uppermost Layer ◽

Pavement Construction

Abstract. Large amounts of quarry wastes are produced during quarrying. Though quarry wastes are commonly used in pavement construction and concrete production, in-situ utilization during ecological restoration of abandoned quarries has its advantage of simplicity. In this paper, rock fragments of 2 ~ 3 cm in size were mixed with landfill stabilized waste (LSW) in different proportions (LSW: gravel, RL), which was called LGM. The water content, runoff and plant growth under natural precipitation were monitored for two years using a runoff plot experiment. LGM with a low fraction of LSW was compacted in different degrees to achieve an appropriate porosity; water dynamic and plant growth of compacted LGM were studied in a field experiment. The results showed that, (1) LGM can be used during restoration in abandoned quarries as growing material for plants. (2) RL had a significant effect on infiltration and water holding capacity of LGM, and thus influenced retention of precipitation, water condition and plant growth. LGM with RL ranging from 8 : 1 to 3 : 7 was suitable for plant growth, but the target species grew best when RL was intermediate. (3) Compaction significantly enhanced water content of LGM with a low RL of 2 : 8, but leaf water content of plants was lower or unchanged in the more compacted plots. Moderate compaction was beneficial to the survival and growth of Robinia pseudoacacia. Platycladus orientalis and Medicago sativa were not significantly affected by compaction, and they grew better under high degree of compaction which was disadvantageous for the uppermost layer of vegetation.

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