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Using Empirical Models To Set EOS Targets For Phase 5. Gary Shenk 1/10/07 Modeling Subcommittee. River Calibration. Rule-Based Optimization. Process Parameter Files. Assume the sensitivity of the simulation to each parameter
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Using Empirical ModelsTo Set EOS Targets For Phase 5 Gary Shenk 1/10/07 Modeling Subcommittee
River Calibration Rule-Based Optimization Process Parameter Files • Assume the sensitivity of the simulation to each parameter • Determine an appropriate adjustment direction for each parameter • Take a small step in that direction
Calibration Information • Consistent with recommendations of STAC review team • Observed and simulated CFDs for paired data
Potomac Calibration Change in transformation vs iteration
How to arrive at appropriate EOS loads? • Assume watershed with one river and a gauge • Start from the outlet • Add stream attenuation • Leaves necessary EOS Segment Transport Factor = EOS / EOF
2 1 3 What about multiple streams? • Each sub-basin has preliminary estimate of EOF • Calculate EOF * product of down stream delivery for each sub-basin • Determine ratio for all preliminary EOF ESTIMATOR = TF * ( EOF1 * DF1 * DF3 + EOF2 * DF2 * DF3 + EOF3 * DF3 )
2 1 3 What about nested streams? • Same as above, but subtract out stations ESTIMATOR(3) = ESTIMATOR(1) * DF3 + TF * ( EOF2 * DF2 * DF3 + EOF3 * DF3 )
Where do we get all of the data? • EOF = targets • Loads at Stations = USGS ESTIMATOR • Stream Attenuation = USGS Sparrow
Estimatorlocations Assign non-gauged areas based on gauged results
In-stream loss:Sparrow formulation Streams are grouped into size categories and each stream group has a particular reduction rate ThetaSc = first-order loss rate for streams of certain size T = Travel time http://pubs.usgs.gov/tm/2006/tm6b3/
Big difference: 2004 included reservoir settling factor at 14.3 meters per year
New Sparrow Formulations Empirical formulation Q = average flow ThetaS[1,2] = empirical coefficients ‘Settling-velocity’ formulation DS = Average Depth ThetaMT = mass settling rate http://pubs.usgs.gov/tm/2006/tm6b3/
River Geomorphology Data Bankfull Height vs Drainage area in the Piedmont
New Sparrow Formulations Reservoir Attenuation: qR = outflow / area ThetaR0 = mass settling rate http://pubs.usgs.gov/tm/2006/tm6b3/
Conclusions • Using mass balance and literature to determining EOS targets results in regional biases • Using ESTIMATOR and Sparrow estimates of river flux and attenuation, we can empirically calculate overall necessary EOS loads. 2 1 3