Development, Verification, and Evaluation of a Solute Transport Model in Surface Irrigation

Persistent Link:
http://hdl.handle.net/10150/194316
Title:
Development, Verification, and Evaluation of a Solute Transport Model in Surface Irrigation
Author:
Perea-Estrada, Hugo
Issue Date:
2005
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A cross-section averaged Advection-Dispersion equation (ADE) model was developed to simulate the transport of fertilizer in furrow irrigation. The advection and dispersion processes were solved separately by implementing the method of the characteristics with cubic spline interpolation (and natural boundary condition) and weighted finite difference scheme respectively. A zero-flux boundary condition during advance and an advective gradient at the downstream end of an open furrow were established. Local pseudo-steady state was assumed in order to apply Fischer's longitudinal dispersion equation under non-uniform and unsteady furrow flow conditions. Also, several parameters were used to evaluate the ADE model and fertigation performance.A field tracer experiment in two types of downstream-end furrow and two treatments was conducted and described. Infiltration and roughness parameters were calibrated by implementing a volume balance approach. The calibrated parameters were used as input data to run the surface irrigation model (SRFR). The roughness coefficient was 0.045 for wheel and 0.055 for non-wheel furrow treatment for bare soil. The root mean square error (RMSE) comparing the computed and observed infiltrated volume was in the range of 0.09-0.38 m3. The close match between simulated and observed data indicates an acceptable calibration. Pulses of fertilizer injected at the head end of four furrows each having unique management characteristics were simulated satisfactorily during the entire duration of the irrigation event. The constant value of the longitudinal dispersion coefficient was 1 m2 min-1 and yielded an acceptable space-time evolution of the pulses of tracer injected. Similar results for the dispersion coefficient were obtained with Fischer's equation in non-uniform and unsteady stream flow conditions in the furrow. An evaluation of several fertigation strategies for furrow systems indicated that fertigation by pulses could help reduce leaching and runoff losses in surface irrigation systems.
Type:
text; Electronic Dissertation
Keywords:
fertigation; advection-dispersion equation; split operator; method of characteristics; longitudinal dispersion; furrow irrigation
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Agricultural & Biosystems Engineering; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Waller, Peter
Committee Chair:
Waller, Peter

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleDevelopment, Verification, and Evaluation of a Solute Transport Model in Surface Irrigationen_US
dc.creatorPerea-Estrada, Hugoen_US
dc.contributor.authorPerea-Estrada, Hugoen_US
dc.date.issued2005en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA cross-section averaged Advection-Dispersion equation (ADE) model was developed to simulate the transport of fertilizer in furrow irrigation. The advection and dispersion processes were solved separately by implementing the method of the characteristics with cubic spline interpolation (and natural boundary condition) and weighted finite difference scheme respectively. A zero-flux boundary condition during advance and an advective gradient at the downstream end of an open furrow were established. Local pseudo-steady state was assumed in order to apply Fischer's longitudinal dispersion equation under non-uniform and unsteady furrow flow conditions. Also, several parameters were used to evaluate the ADE model and fertigation performance.A field tracer experiment in two types of downstream-end furrow and two treatments was conducted and described. Infiltration and roughness parameters were calibrated by implementing a volume balance approach. The calibrated parameters were used as input data to run the surface irrigation model (SRFR). The roughness coefficient was 0.045 for wheel and 0.055 for non-wheel furrow treatment for bare soil. The root mean square error (RMSE) comparing the computed and observed infiltrated volume was in the range of 0.09-0.38 m3. The close match between simulated and observed data indicates an acceptable calibration. Pulses of fertilizer injected at the head end of four furrows each having unique management characteristics were simulated satisfactorily during the entire duration of the irrigation event. The constant value of the longitudinal dispersion coefficient was 1 m2 min-1 and yielded an acceptable space-time evolution of the pulses of tracer injected. Similar results for the dispersion coefficient were obtained with Fischer's equation in non-uniform and unsteady stream flow conditions in the furrow. An evaluation of several fertigation strategies for furrow systems indicated that fertigation by pulses could help reduce leaching and runoff losses in surface irrigation systems.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectfertigationen_US
dc.subjectadvection-dispersion equationen_US
dc.subjectsplit operatoren_US
dc.subjectmethod of characteristicsen_US
dc.subjectlongitudinal dispersionen_US
dc.subjectfurrow irrigationen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAgricultural & Biosystems Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorWaller, Peteren_US
dc.contributor.chairWaller, Peteren_US
dc.contributor.committeememberWaller, Peteren_US
dc.contributor.committeememberStrelkoff, Theodore S.en_US
dc.contributor.committeememberAdamsen, Floyd J.en_US
dc.contributor.committeememberHunsaker, Douglas J.en_US
dc.contributor.committeememberWarrick, Arthur W.en_US
dc.contributor.committeememberChoi, Christopher Y.en_US
dc.identifier.proquest1322en_US
dc.identifier.oclc137355020en_US
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