2nd UF Water Institute Symposium Abstract

Submitter's Name Oscar Perez-Ovilla
Session Name Poster Session: Hydrologic, Biogeochemical and Ecological Processes 1
Category Hydrologic, biogeochemical and ecological processes
Poster Number 235
Author(s) Oscar Perez-Ovilla,  Graduate Student/Assistant
  Rafael Muñoz-Carpena,  UF Associate Professor
  Congrong Yu, Graduate Student
  Bin Gao, UF Assistant Professor
  Flexible simulation of surface runoff pollutants through dense vegetation
  Vegetative Filter Strips (VFS) are one of the most widely recommended best management practices (BMP) by many state and federal agencies to control non point-source pollution from disturbed land areas. Our goal is to understand the dynamics of runoff pollutants through dense vegetation areas like VFS, that allow us to better predict the efficiency of pollutant removal in different scenarios (climatic, scale, length, slope, vegetation in VFS, soil, etc). VFSMOD (Carpena et. al. 1999) is one of the programs recommended by the Environmental Protection Agency and other federal and state agencies to design VFS. In order to provide the capability to simulated an unlimited number of pollutants in VFSMOD, a module to handle solute transport (FEMADR) was developed based on the solution of the 1-D Advective-Dispersive equation using a standard Bubnov-Galerkin cubic/quadratic finite elements method, and then coupled with a flexible biogeochemical multi-species reaction module (RSE) (James et. al., 2009). The advantage of the coupled component (FEMADR-RSE) is that pollutants of very different types can be simulated with the same program through conceptual models defined through the XML user interface. The coupled component (FEMADR-RSE) is first tested by comparing with analytical solutions of 1D reactive transport, and then used to predict experimental bench-scale surface transport of a tracer. Yu (unpublished, 2009) designed a laboratory experiment to trace a plug of bromide runoff at constant flow in a 1.5 x 0.5m sand bed under simulated rainfall. The experimental bromide runoff data was used to create and test a conceptual model to be used in the flexible FEMADR-RSE module for predicting bromide dynamics in surface runoff. The positive implications of this novel approach are that transport and fate dynamics of specific pollutants (either physical, chemical or microbiological) in VFS and natural areas of dense vegetation can be readily modeled. It is expected that the approach will serve as an exploratory tool for researchers and to develop simplified models to support environmental decision-making.