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RECORD NUMBER: 200 OF 781

OLS Field Name OLS Field Data
Main Title DO Model Uncertainty with Correlated Inputs.
Author Song, Q. ; Brown, L. C. ;
CORP Author Nanjing Univ. (China). ;Tufts Univ., Medford, MA. Dept. of Civil Engineering.;Environmental Research Lab., Athens, GA.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/457;
Stock Number PB91-183335
Additional Subjects Water quality ; Computerized simulation ; Mathematical models ; Nitrification ; Biochemical oxygen demand ; Monte Carlo method ; Algae ; Sediments ; Oxygenation ; Stream flow ; Reprints ; Streeter-Phelps water quality model
Holdings
Library Call Number Additional Info Location Last
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Status
NTIS  PB91-183335 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 09/04/1991
Collation 19p
Abstract
The effect of correlation among the input parameters and variables on the output uncertainty of the Streeter-Phelps water quality model is examined. Three uncertainty analysis techniques are used: sensitivity analysis, first-order error analysis, and Monte Carlo simulation. A modified version of the Streeter-Phelps model that includes nitrification, net algal oxygen production, and sediment oxygen demand is used. Analyses are performed for a wide variety of simulated stream flow conditions. Results show that the standard deviation of the predicted dissolved oxygen deficit (DOD) with correlated inputs potentially can be 20-40% larger than with independent inputs. Under conditions of moderate to high velocity, the reaeration and bio-oxidation coefficients are the dominant contributors to DOD uncertainty, while net oxygen production from algal activity and sediment oxygen demand are the major factors at low velocity. The largest effect of input correlation on DOD occurs in the vicinity of the sag point. Uncertainty results from first-order analysis differ by at most 10% from those of a Monte Carlo simulation for both correlated and independent inputs. (Copyright (c) 1990, ASCE.)