"VFS Effectiveness to Mitigate Pesticides: Mechanistic Analysis with VFSMOD - Identifying important drivers in quantitative pesticide mitigation exposure assessments"
Speaker: Dr. Rafael Muñoz-Carpena
Abstract: Pesticides high-tier, long-term environmental risk assessments (ERA) are based on the combination of complicated mechanistic models to evaluate regulatory compliance. The modeling framework often involves large sets of input factors (model parameters, initial and boundary conditions, and other model structure options). How can we identify the relative importance of human, chemical, physical and biological drivers on the assessment results? Is there a case for “the right answers for the right reasons”? For the case of pesticide mitigation practices like vegetative filter strips (VFS) for runoff mitigation, what are the important factors controlling or limiting their efficiency under different field settings? We evaluate the combination of the current ERA frameworks (US EPA PWC and EU FOCUS SWAN) in combination with VFSMOD, an established and commonly used numerical model for the analysis of runoff, sediment, and pesticide transport in VFS. We present a systematic study of the importance of different field conditions that have been proposed in the past as limiting the efficiency of VFS in realistic settings: flow concentration (channelization) through the filter, timing of pesticide application compared to other drivers, assumptions about the degradation and remobilization of pesticide trapped in the filter between runoff events, seasonal presence of a shallow water table near the receiving water body. We identify instances in which the importance commonly assigned to these factors is not supported by the mechanistic analysis, where other factors different than those proposed largely control the results of the assessments.
Bio: Dr. Rafael Muñoz-Carpena is a Full Professor of Hydrology and Environmental Modeling at the University of Florida,Gainesville, USA. He is an Agricultural en Biological Engineer (ETSIA Madrid, Spain; Ph.D. North Carolina State University) specializing in water resources and modeling. His work focuses on modelling integrated environmental systems, including the interactions between hydrological, ecological and human components. He developed the VFSMOD model to study the effect of plant filters as a mitigation measure to reduce pollution from agro-chemical products in runoff.
He is passionate about graduate advising and has supervised 20 PhD dissertations, 8 M.Sc. thesis, and 8 postdoctoral researchers who are currently in prestigious academic, government and industry positions around the world. He is the author of over 150 publications in peer-reviewed international journals, 2 books, 11 book chapters and 350 other technical publications. He is an elected Fellow of AAAS, Fellow of ASABE, and Corresponding Member of the Spanish Royal Academy of Engineering (RAIng). He currently serves as Editor-in-Chief of Elsevier’s Journal of Hydrology: Regional Studies
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