Identifier

etd-06022017-154919

Degree

Doctor of Philosophy (PhD)

Department

Environmental Sciences

Document Type

Dissertation

Abstract

The Environmental Protection Agency (EPA) model Pesticide Root Zone Model, version 5.0 (PRZM5.0) is used to estimate off-field loadings of pesticide concentrations in runoff and eroded sediment. Climate change has resulted in an increase in rainfall intensity patterns for much of the United States. This change impacts off-field runoff and eroded sediment as well as off-field pesticide loads from agricultural fields. Thus, the PRZM5.0 EPA “lookup” table for runoff curve numbers and the internal algorithm for eroded sediment estimation have become outdated since both temporal and geographical conditions have changed. This research presents (1) a revised method for estimating runoff curve numbers that better represent current rainfall intensity patterns as well as more geographically representative based on the Natural Resources Conservation Service (NRCS) single event method for estimating runoff curve numbers; (2) a revised PRZM5.0 version with a modified erosion algorithm that includes empirical coefficients from an 2014 NRCS updated storm intensity system and (3) examination of the effect of these PRZM5.0 revisions for six EPA standard environmental crop modelling scenarios and three example pesticides compared to the established EPA practices.

Date

2017

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Armbrust, Kevin L.

Available for download on Saturday, February 23, 2019

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