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Identifying Model Structure and Scale Dependencies in Complex Sytems. Donna M. Rizzo College of Engineering & Mathematical Sciences University of Vermont, Burlington, VT. Conclusions. There’s no such thing as “correct scale”… (it’s problem dependent)
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Identifying Model Structure and Scale Dependencies in Complex Sytems Donna M. Rizzo College of Engineering & Mathematical Sciences University of Vermont, Burlington, VT
Conclusions • There’s no such thing as “correct scale”… (it’s problem dependent) • Keys: - recognizing when a change in scale has occurred - determining what information (and what scale) data must be collected
High High ForecastingQuality IncrementalImpact ofData Low Low Many Few Amount of Data and Information Modeling & Maturity of Site Understanding
High High Incremental Impact ofData ForecastingQuality Low Low Amount of Data and Information Many Few Rule-Based Systems Decision Trees KBES Screening Tools Agent Based Models Statistical Geostatistics Parametric Nonparametric Physics-Based Analytical 2-D Numerical 3-D Numerical Physical-Statistical Kalman Filter based
& Parameter Estimation “What we call scientific knowledge today is a body of statements of varying degrees of certainty.Some of them are most unsure; some of them are nearly sure; but none is absolutely certain.” R. P. Feynmann,The Uncertainty of Science, John Danz Lecture, April 23, 1963 3-D Physics-based Modeling
Berea Sandstone Data Data collected by New England Research, Inc. (see Boinott, G. N., G. Y. Bussod, et al., 2004. "Physically Based Upscaling of Heterogeneous Porous Media: An Illustrated Example Using Berea Sandstone." The Leading Edge.
Sandstone Air Permeability Air Permeability Omnidirectional Variogram 15000 Semi-Variogram Bin Averages 95% Confidence Limit 10000 (permeability) 5000 g 0 0 50 100 150 200 250 300 350 Distance (mm) Ordinary Cokriging Permeability Estimates ANN Estimates of Permeability Geostatistics (Kriging Methods)
“Observation is the judge of whether something is so or not.” R. P. Feynmann,The Uncertainty of Science, John Danz Lecture, April 23, 1963 3-D Physics-based Modeling & Kalman Filter-Based Calibration
HGL Model, July, 1999 Initial C (ppb), Jan., 1998 Bayesian, July, 1999 Kriged, July, 1999 Combining Geostatistics with Process Modeling
“The extrapolations are the only things that have any real value. … Knowledge is of no real value if all you can tell me is what happened yesterday….you must be willing to stick your neck out.” R. P. Feynmann,The Uncertainty of Science, John Danz Lecture, April 23, 1963 Forecast Modeling & Optimization
Unconstrained Optimization Approach N N p w å å = + + ) q F N F f ( l C , C , W,T i treat w cap MCL = = 1 1 k i (1) Minimize Real $$$+l * (Performance & Resource Targets)
Mass Remaining and Cost Yielded asymptotic value of mass that cannot be further reduced without applying different remediation Cost ($ 10M) Mass (Mg) Performance-Cost “Ratio” Time (years) Time (years) l = 1 Rizzo and Dougherty [1996] l = 5 l = 10 Motivation Which scheme is “optimal” ? - How long do we really have to operate? - How long do we really have to monitor? - How much residual risk are we willing to accept? - Will a new technology or public policy shift become available?
Improving site characterization & monitoring environmental change using microbial profiles and geochemistry in landfill-leachate contaminated groundwater Paula J. Mouser1 Donna M. Rizzo1 Patrick O’Grady2 Lori Stevens2 Greg Druschel3 1Department of Civil & Environmental Engineering2Department of Biology, Ecology & Evolutionary Systematics 3Department of Geology
Microbial Analysis Techniques Take Groundwater Samples
Microbial Analysis Techniques Take Groundwater Samples Isolate DNA
Microbial Analysis Techniques Take Groundwater Samples Isolate DNA Polymerase Chain Reaction (PCR)
Microbial Analysis Techniques Take Groundwater Samples Isolate DNA Polymerase Chain Reaction (PCR) Terminal Restriction Fragment Length Polymorphism (T-RFLP)
Identifying contamination at landfill sites without prior knowledge
Contaminated Fringe Delineation of the Extent of Contamination
Acknowledgements • Vermont EPSCoR • New England Research, Inc. • Clinton County, NY • Casella & New England Waste Services • Bernie Nadeau, Craig Squires