Evaluation of preferential flow component of RZWQM in simulating water and atrazine transport to subsurface drains

dc.contributor.author Kumar, Ajay
dc.contributor.author Kanwar, Rameshwar
dc.contributor.author Ahuja, Lajpat
dc.contributor.department Agricultural and Biosystems Engineering
dc.date 2018-02-17T05:47:00.000
dc.date.accessioned 2020-06-29T22:41:39Z
dc.date.available 2020-06-29T22:41:39Z
dc.date.issued 1998
dc.description.abstract <p>The ARS Root Zone Water Quality Model (RZWQM ver. 3.25) was used to simulate the effect of field measured macroporosity on atrazine transport to subsurface drain lines. Field data on atrazine concentrations in subsurface drain flow from corn fields, for modified no-till (mNT) and moldboard plow (MP) systems, were used to evaluate the performance of the RZWQM for the growing seasons of 1990, 1991 and 1992. The model was calibrated using field data from 1990 and data from 1991and 1992 were used to validate the model. Simulated subsurface drain flows and atrazine losses with and without macropore flow were compared with measured values. Although the preferential flow component slightly improved the predictions of peak subsurface drain flows for individual rain storms, it did not affect significantly the total annual flows. Simulated annual subsurface flows were within 11.6% of the observed values. Simulated atrazine concentrations in subsurface drain flows using mean values of macroporosity were in close agreement with the observed concentrations for 1990 (calibration year). Predicted total annual atrazine losses were also close to the observed values for 1990 (percentage difference = 17.6% for mNT and 34.8% for MP system). For 1991 and 1992 (evaluation years), with macropores, the simulated atrazine losses for mNT plots were within –9.9% of observed values and for MP plots were within +12.0% of observed values (combined for two years). The RZWQM predicted only trace amounts of atrazine in subsurface drain flows if macropores were not considered. The model showed sensitivity to lateral flow from macropores, Ksat of surface layer, and macroporosity in decreasing order in simulating atrazine losses to subsurface drain flows. Overall, the RZWQM showed good potential for simulating atrazine losses with subsurface drain water as affected by tillage practices.</p>
dc.description.comments <p>This article was published in Transactions of the ASAE 41(3): 627–637, doi:<a href="http://dx.doi.org/10.13031/2013.17231">10.13031/2013.17231</a>.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/abe_eng_pubs/660/
dc.identifier.articleid 1962
dc.identifier.contextkey 7834540
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath abe_eng_pubs/660
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/1450
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/abe_eng_pubs/660/1998_Kumar_EvaluationPreferential.pdf|||Sat Jan 15 01:25:43 UTC 2022
dc.source.uri 10.13031/2013.17231
dc.subject.disciplines Agriculture
dc.subject.disciplines Bioresource and Agricultural Engineering
dc.subject.disciplines Environmental Indicators and Impact Assessment
dc.subject.disciplines Hydrology
dc.subject.disciplines Water Resource Management
dc.subject.keywords Preferential flow
dc.subject.keywords Groundwater
dc.subject.keywords Chemical transport
dc.subject.keywords Tillage
dc.subject.keywords Hydrology
dc.subject.keywords RZWQM
dc.subject.keywords Atrazine
dc.title Evaluation of preferential flow component of RZWQM in simulating water and atrazine transport to subsurface drains
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication 5210e67e-b8da-4e17-be3f-843a09381196
relation.isOrgUnitOfPublication 8eb24241-0d92-4baf-ae75-08f716d30801
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