Simulation of water and solute transport with MACRO model in Cecil loamy sand soil

Soil Research ◽  
2004 ◽  
Vol 42 (8) ◽  
pp. 939 ◽  
Author(s):  
Hasan Merdun ◽  
Virgil L. Quisenberry
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Preferential Flow ◽  
Effective Diffusion ◽  
Loamy Sand ◽  
Model Parameters ◽  
Drainage Flow ◽  
Sand Soil ◽  
Flow And Transport ◽  
Loamy Sand Soil

Modelling preferential flow increases understanding of flow and transport processes in the unsaturated (vadose) zone and, hence, helps prevention of groundwater contamination. A dual-porosity model, MACRO, was evaluated for long-term drainage flow and short-term chloride-tagged water flow simulations in well-structured Cecil loamy sand soil. Water flow in micropores is calculated by the Richards’ equation, and simple gravity flow is assumed in the macropores. Solute transport in the micropores is calculated by the convection–dispersion equation (CDE), and the dispersion and diffusion in the CDE is neglected for the solute transport in the macropores. Based on the statistical criteria, the model accurately simulated drainage flow with depth and time. The average values of 3 statistical parameters (coefficient of residual mass, model efficiency, correlation coefficient) for drainage flow of different plots and times were 0.0057, 0.972, and 0.987, respectively. Similarly, the average values of the 3 statistical parameters in the same order for water flow and chloride transport of 4 plots were 0.097, 0.628, and 0.915, and 0.167, 0.938, and 0.982, respectively. The model simulated long-term drainage flow better than the short-term applied chloride-tagged water. The percentage recovery of measured water and chloride 2 h after the application ceased was 83 and 63 in the 1.05-m-deep profile of plot 1. This was a strong indication of preferential flow in this soil. Two-domain flow concept was required for acceptable simulation of this type of flow. In the 2-domain flow, boundary tension, boundary hydraulic conductivity, and effective diffusion path-length were the 3 most important parameters controlling flow and transport between the 2 domains. The effective diffusion path-length represented the structural development with depth in Cecil loamy sand soil. The relationships between the variability in flow and transport characteristics and fundamental soil properties and, hence, the associated key model parameters suggest that pedotransfer functions can be developed for the estimation of dual-porosity model parameters that control preferential flow.

scholarly journals Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

2012 ◽  
Vol 9 (2) ◽  
pp. 2245-2282 ◽  
Author(s):  
J. Moeys ◽  
M. Larsbo ◽  
L. Bergström ◽  
C. D. Brown ◽  
Y. Coquet ◽  
...  
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Preferential Flow ◽  
General Pattern ◽  
Regional Scale ◽  
Model Parameters ◽  
Model Efficiency ◽  
Fate Model ◽  
Solute Leaching ◽  
Pesticide Leaching

Abstract. Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisation usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

scholarly journals Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

2012 ◽  
Vol 16 (7) ◽  
pp. 2069-2083 ◽  
Author(s):  
J. Moeys ◽  
M. Larsbo ◽  
L. Bergström ◽  
C. D. Brown ◽  
Y. Coquet ◽  
...  
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Preferential Flow ◽  
General Pattern ◽  
Regional Scale ◽  
Model Parameters ◽  
Model Efficiency ◽  
Fate Model ◽  
Solute Leaching ◽  
Pesticide Leaching

Abstract. Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the estimation of water flow parameters. Overall, the results are encouraging for the use of this modelling set-up to estimate pesticide leaching risks at the regional-scale, especially where the objective is to identify vulnerable soils and "source" areas of contamination.

The Daisy agroecological system model: A physically based model for preferential water flow and solute transport in drained agricultural fields

2021 ◽  
Author(s):  
Efstathios Diamantopoulos ◽  
Maja Holbak ◽  
Per Abrahamsen
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Preferential Flow ◽  
Column Experiment ◽  
Soil Matrix ◽  
Physically Based Model ◽  
Physically Based ◽  
Rapid Transport ◽  
Preferential Water

<p>Preferential water flow and solute transport in agricultural systems affects not only the quality of groundwater but also the quality of surface waters like streams and lakes. This is due to the rapid transport of agrochemicals, immediately after application, through subsurface drainpipes and surface water. Experimental evidence attributes this to the occurrence of continuously connected pathways, connecting the soil surface directly with the drainpipes. We developed a physically-based model describing preferential flow and transport in biopores and implemented it in the agroecological model Daisy. The model simulates the often observed rapid transport of chemicals from   the upper soil layers to the drainpipes or to deeper layers of the soil matrix. Based on field investigations, biopores with specific characteristics can be parameterized as classes with different vertical and horizontal distributions. The model was tested against experimental data from a column experiment with an artificial biopore and showed good results in simulating preferential flow dynamics. We illustrate the performance of the new approach, by conducting five simulations assuming a two-dimensional simulation domain with different biopore parametrizations, from none to several different classes. The simulation results agreed with experimental observations reported in the literature, indicating rapid transport from the soil to the drainpipes. Furthermore, the different biopore parametrizations resulted in distinctly different leaching patterns, raising the expectation that biopore properties could be estimated or constrained based on observed leaching data and direct measurements.</p>

Agricultural hillslope soil heterogeneity challenges: first experimental results from SUPREHILL critical zone observatory

2021 ◽  
Author(s):  
Vedran Krevh ◽  
Jasmina Defterdarović ◽  
Lana Filipović ◽  
Zoran Kovač ◽  
Steffen Beck-Broichsitter ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Soil Moisture ◽  
Solute Transport ◽  
Soil Water ◽  
Water Flow ◽  
Preferential Flow ◽  
Soil Heterogeneity ◽  
Local Scale ◽  
Soil Water Flow ◽  
Critical Zone Observatory

<p>SUPREHILL is a new (2020) and first Croatian critical zone observatory (CZO), focused on local scale agricultural e.g., vineyard hillslope processes. The experimental setup includes an extensive sensor-based network accompanied by weighing lysimeters and instruments for surface and subsurface hydrology measurement. The field measurements are supported by novel laboratory and numerical quantification methods for the determination of water flow and solute transport. This combined approach will allow the research team to accurately determine soil water balance components (soil water flow, preferential flow/transport pathways, surface runoff, evapotranspiration), the temporal origin of water in hillslope hydrology (isotopes), transport of agrochemicals, and to calibrate and validate numerical modeling procedures for describing and predicting soil water flow and solute transport. First results from sensors indicate increased soil moisture on the hilltop, which is supported by precipitation data from rain gauges and weighing lysimeters. The presence of a compacted soil horizon and compacted inter-row parts (due to trafficking) of the vineyard seems to be highly relevant in regulating water dynamics. Wick lysimeters confirm the sensor soil moisture data, while showing a significant difference in its repetitions which suggests a possibility of a preferential flow imposed by local scale soil heterogeneity. Measured values of surface and subsurface runoff suggest a crucial role of these processes in the hillslope hydrology, while slope and structure dynamics additionally influence soil hydraulic properties. We are confident that the CZO will give us new insights in the landscape heterogeneity and substantially increase our understanding regarding preferential flow and nonlinear solute transport, with results directly applicable in agricultural (sloped agricultural soil management) and environmental (soil and water) systems. Challenges remain in characterizing local scale soil heterogeneity, dynamic properties quantification and scaling issues for which we will rely on combining CZO focused measurements and numerical modeling after substantial data is collected.</p>

scholarly journals Evaluation of MACRO model by short-term water and solute transport simulation in Maury silt loam soil

2011 ◽  
Vol 51 (No. 3) ◽  
pp. 110-123 ◽  
Author(s):  
H. Merdun ◽  
V.L. Quisenberry
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Chloride Transport ◽  
Effective Diffusion ◽  
Diffusion Path ◽  
Silt Loam ◽  
Short Term ◽  
Silt Loam Soil ◽  
Diffusion Path Length ◽  
Loam Soil

Modeling preferential flow has been a concern of many academic fields in the past 30 years all over the world and helps to prevent groundwater contamination. A dual-porosity model, MACRO, was evaluated for short-term (less than 2 days) simulation of water flow and non-reactive solute (chloride) transport through the profile of six plots in well-structured Maury silt loam soil. Water flow in micropores is calculated by the Richards’ equation while simple gravity flow is assumed in the macropores. Solute transport in the micropores is calculated by the convection-dispersion equation (CDE) while the dispersion and diffusion in the CDE is neglected for the solute transport in the macropores. The applied water and chloride reached the bottom of the profile during the 2 and 1-hour(s) application periods in studies 2 and 3, respectively. There is a strong indication of macropore flow in this soil. Based on the statistical criteria, the model accurately simulated water flow and solute transport with depth and time in all plots. The mean values of three statistical parameters (coefficient of residual mass, model efficiency, and correlation coefficient) for water and chloride transport were –0.0014, 0.791, 0.903 and 0.0333, 0.923, 0.956, respectively. Preliminary studies showed that the model could not simulate flow and transport well enough with the one-domain flow concept. In the two-domain flow, effective diffusion path-length, boundary hydraulic conductivity, and boundary soil water pressure were the three most important parameters that control flow and transport between the two domains. The effective diffusion path-length represented the structural development with depth in the Maury silt loam soil.

scholarly journals Effect of Macro- and Nano-Biosolid Fractions on Sorption Affinity and Transport of Pb in a Loamy Sand Soil

2019 ◽  
Vol 11 (12) ◽  
pp. 3460 ◽  
Author(s):  
Abdulaziz G. Alghamdi ◽  
Hesham M. Ibrahim
Keyword(s):  
Surface Area ◽  
Land Application ◽  
Surface Reactivity ◽  
Loamy Sand ◽  
Field Scale ◽  
Sand Soil ◽  
Loamy Sand Soil ◽  
Fraction Size ◽  
Potential Impact ◽  
Potential Mobility

Applications of large amounts of biosolid to agricultural lands have raised the concern over its potential impact on co-transport of metal contaminants. In this study, bulk biosolid was fractioned into six macro- and nano-biosolid fraction sizes. We investigated variations in the physicochemical properties of the different biosolid fraction sizes, and assessed sorption affinity and transport of Pb in a loamy sand soil. Decreasing biosolid fraction size from macro to nano resulted in consistent increases in surface area, surface charge, and a decrease in pore size. Biosolid particles >1000 µm showed similar surface properties that differ from biosolid particles < 1000 µm. Sorption affinity for Pb was larger on nano-biosolid as compared to all macro-biosolid fraction sizes. This is mainly attributed to the larger surface area and zeta potential of nano-biosolid, leading to increased surface reactivity and greater stability. Total amount eluted of Pb was increased in the presence of macro- and nano-biosolid by 21.3% and 45.6%, respectively. Our findings suggest that the application of the >1000 µm biosolid fractions can help to minimize adverse effects of biosolid applied in areas susceptible to potential environmental risk of contamination by heavy metals. Further assessment of potential mobility of nano-biosolid at the field scale is needed before the recommendation of including such approach during land application of biosolid.

A Study of Compaction and Crop Yields in Loamy Sand Soil After Seven Years of Reduced Tillage

1986 ◽  
Vol 29 (2) ◽  
pp. 0389-0392 ◽  
Author(s):  
Jonathan Chaplin ◽  
Mike Lueders ◽  
David Rugg
Keyword(s):  
Crop Yields ◽  
Loamy Sand ◽  
Reduced Tillage ◽  
Sand Soil ◽  
Loamy Sand Soil
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