Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 8, 2009
Publication Date: October 14, 2009
Citation: Pachepsky, Y.A., Gish, T.J. 2009. Beltsville OPE3 Site Studies to Support Model Abstraction and Uncertainty Analyses. Interagency Environmental Modeling Workshop and Public Meeting. Rockville, MD, October 13-15, 2009. Meeting Abstract., p. 14 Technical Abstract: Studies were designed and performed to demonstrate the applicability of model abstraction techniques to subsurface flow and contaminant transport problems. Our main objective was to use modeling along with field and laboratory observations to improve the characterization of flow and transport processes in the subsurface. A systematic model abstraction methodology was developed and tested in previous work on flow in soils. With additional studies, we aimed to test and confirm the application of model abstraction to pollutant transport processes in soils and shallow groundwater systems. The OPE3 experimental field site near Beltsville, MD, has been extensively studied for more than 10 years using geophysical, biophysical, remote sensing, and soil and groundwater monitoring methods Available data were analyzed using a systematic procedure based on a broad vadose zone modeling context developed in this study. A major focus was on the existence of subsurface structural units and features that may drastically change the fate and transport of contaminants in the vadose zone. Two test cases were developed that included field tracer experiments and subsequent modeling with a series of sequentially simplified models. Overall, this study demonstrated the usefulness of model abstraction in simulations of flow and transport in a variably-saturated subsurface. Whereas multidimensional and multi-process representations leaves room for several competing conceptual models for flow and transport, simpler models that retain the most essential features of those representations could provide meaningful alternatives.