Estimating macropore parameters for HYDRUS using a meta-model

Carlos Alberto Faúndez Urbina; Jos van Dam; Darell Tang; Harm Gooren; Coen Ritsema

doi:10.1111/ejss.13103

Estimating macropore parameters for HYDRUS using a meta-model

Carlos Alberto Faúndez Urbina^*, Jos van Dam, Darell Tang, Harm Gooren, Coen Ritsema

^*Corresponding author for this work

Research output: Contribution to journal › Article › Academic › peer-review

3 Citations (Scopus)

Abstract

The vertical change in the number of macropores causes a variation of the relative macroporosity (w_f) and the effective aggregate width (d_ag) over the soil profile. Both parameters are used in HYDRUS to represent this variation, increasing the number of parameters and making automated calibration challenging. The working hypothesis is that we can improve an analytical estimation of w_f and d_ag developed in previous research by inverse estimation with a meta-model for HYDRUS 2D/3D, using disk infiltrometer data of infiltration at zero pressure head. We generate a meta-model that describes the vertical heterogeneity of the macropore number with a general function using four parameters: the relative macroporosity at the soil surface (w_fs), the effective macropore radius (r_m), the maximum depth of macropores (z_max) and the shape parameter of the w_f curve (m). The meta-model computes the variation of w_f and d_ag over depth, thus reducing the parameters for automated calibration with HYDRUS. We theoretically described how to directly obtain the meta-model parameters with disk infiltrometer data, providing an example for field conditions. A complete parametrization of matrix and macropore parameters for HYDRUS 2D/3D was generated from these data and previous studies, which were updated by automated calibration. Only w_fs was calibrated, increasing by about ~3.5 times the initial measurement. We tied several macropore parameters to w_fs during calibration by their physical or mathematical relations. This methodology can be utilized to estimate HYDRUS parameters for risk assessment or detailed plot studies. Highlights: A meta-model to estimate macropore parameters for HYDRUS 2D/3D is presented. The meta-model reduces the number of macropore parameters for HYDRUS 2D/3D. Initial estimations of meta-model parameters are obtained by disk infiltrometer. The parameters were updated through calibration with HYDRUS 2D/3D. Preferential flow is predicted by a two-dimensional model.

Original language	English
Pages (from-to)	2006-2019
Journal	European Journal of Soil Science
Volume	72
Issue number	5
Early online date	6 Mar 2021
DOIs	https://doi.org/10.1111/ejss.13103
Publication status	Published - 2021

Keywords

diffusion path length
disk infiltrometers
effective aggregate width
macropore flow
relative macroporosity

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https://edepot.wur.nl/545760Licence: CC BY

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title = "Estimating macropore parameters for HYDRUS using a meta-model",

abstract = "The vertical change in the number of macropores causes a variation of the relative macroporosity (wf) and the effective aggregate width (dag) over the soil profile. Both parameters are used in HYDRUS to represent this variation, increasing the number of parameters and making automated calibration challenging. The working hypothesis is that we can improve an analytical estimation of wf and dag developed in previous research by inverse estimation with a meta-model for HYDRUS 2D/3D, using disk infiltrometer data of infiltration at zero pressure head. We generate a meta-model that describes the vertical heterogeneity of the macropore number with a general function using four parameters: the relative macroporosity at the soil surface (wfs), the effective macropore radius (rm), the maximum depth of macropores (zmax) and the shape parameter of the wf curve (m). The meta-model computes the variation of wf and dag over depth, thus reducing the parameters for automated calibration with HYDRUS. We theoretically described how to directly obtain the meta-model parameters with disk infiltrometer data, providing an example for field conditions. A complete parametrization of matrix and macropore parameters for HYDRUS 2D/3D was generated from these data and previous studies, which were updated by automated calibration. Only wfs was calibrated, increasing by about ~3.5 times the initial measurement. We tied several macropore parameters to wfs during calibration by their physical or mathematical relations. This methodology can be utilized to estimate HYDRUS parameters for risk assessment or detailed plot studies. Highlights: A meta-model to estimate macropore parameters for HYDRUS 2D/3D is presented. The meta-model reduces the number of macropore parameters for HYDRUS 2D/3D. Initial estimations of meta-model parameters are obtained by disk infiltrometer. The parameters were updated through calibration with HYDRUS 2D/3D. Preferential flow is predicted by a two-dimensional model.",

keywords = "diffusion path length, disk infiltrometers, effective aggregate width, macropore flow, relative macroporosity",

author = "{Fa{\'u}ndez Urbina}, {Carlos Alberto} and {van Dam}, Jos and Darell Tang and Harm Gooren and Coen Ritsema",

year = "2021",

doi = "10.1111/ejss.13103",

language = "English",

volume = "72",

pages = "2006--2019",

journal = "European Journal of Soil Science",

issn = "1351-0754",

publisher = "Wiley",

number = "5",

}

TY - JOUR

T1 - Estimating macropore parameters for HYDRUS using a meta-model

AU - Faúndez Urbina, Carlos Alberto

AU - van Dam, Jos

AU - Tang, Darell

AU - Gooren, Harm

AU - Ritsema, Coen

PY - 2021

Y1 - 2021

N2 - The vertical change in the number of macropores causes a variation of the relative macroporosity (wf) and the effective aggregate width (dag) over the soil profile. Both parameters are used in HYDRUS to represent this variation, increasing the number of parameters and making automated calibration challenging. The working hypothesis is that we can improve an analytical estimation of wf and dag developed in previous research by inverse estimation with a meta-model for HYDRUS 2D/3D, using disk infiltrometer data of infiltration at zero pressure head. We generate a meta-model that describes the vertical heterogeneity of the macropore number with a general function using four parameters: the relative macroporosity at the soil surface (wfs), the effective macropore radius (rm), the maximum depth of macropores (zmax) and the shape parameter of the wf curve (m). The meta-model computes the variation of wf and dag over depth, thus reducing the parameters for automated calibration with HYDRUS. We theoretically described how to directly obtain the meta-model parameters with disk infiltrometer data, providing an example for field conditions. A complete parametrization of matrix and macropore parameters for HYDRUS 2D/3D was generated from these data and previous studies, which were updated by automated calibration. Only wfs was calibrated, increasing by about ~3.5 times the initial measurement. We tied several macropore parameters to wfs during calibration by their physical or mathematical relations. This methodology can be utilized to estimate HYDRUS parameters for risk assessment or detailed plot studies. Highlights: A meta-model to estimate macropore parameters for HYDRUS 2D/3D is presented. The meta-model reduces the number of macropore parameters for HYDRUS 2D/3D. Initial estimations of meta-model parameters are obtained by disk infiltrometer. The parameters were updated through calibration with HYDRUS 2D/3D. Preferential flow is predicted by a two-dimensional model.

AB - The vertical change in the number of macropores causes a variation of the relative macroporosity (wf) and the effective aggregate width (dag) over the soil profile. Both parameters are used in HYDRUS to represent this variation, increasing the number of parameters and making automated calibration challenging. The working hypothesis is that we can improve an analytical estimation of wf and dag developed in previous research by inverse estimation with a meta-model for HYDRUS 2D/3D, using disk infiltrometer data of infiltration at zero pressure head. We generate a meta-model that describes the vertical heterogeneity of the macropore number with a general function using four parameters: the relative macroporosity at the soil surface (wfs), the effective macropore radius (rm), the maximum depth of macropores (zmax) and the shape parameter of the wf curve (m). The meta-model computes the variation of wf and dag over depth, thus reducing the parameters for automated calibration with HYDRUS. We theoretically described how to directly obtain the meta-model parameters with disk infiltrometer data, providing an example for field conditions. A complete parametrization of matrix and macropore parameters for HYDRUS 2D/3D was generated from these data and previous studies, which were updated by automated calibration. Only wfs was calibrated, increasing by about ~3.5 times the initial measurement. We tied several macropore parameters to wfs during calibration by their physical or mathematical relations. This methodology can be utilized to estimate HYDRUS parameters for risk assessment or detailed plot studies. Highlights: A meta-model to estimate macropore parameters for HYDRUS 2D/3D is presented. The meta-model reduces the number of macropore parameters for HYDRUS 2D/3D. Initial estimations of meta-model parameters are obtained by disk infiltrometer. The parameters were updated through calibration with HYDRUS 2D/3D. Preferential flow is predicted by a two-dimensional model.

KW - diffusion path length

KW - disk infiltrometers

KW - effective aggregate width

KW - macropore flow

KW - relative macroporosity

U2 - 10.1111/ejss.13103

DO - 10.1111/ejss.13103

M3 - Article

AN - SCOPUS:85102895265

SN - 1351-0754

VL - 72

SP - 2006

EP - 2019

JO - European Journal of Soil Science

JF - European Journal of Soil Science

IS - 5

ER -

Estimating macropore parameters for HYDRUS using a meta-model

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Keywords

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