Neuse River Estuary Modeling and Monitoring Project Stage 1: Predictions andUncertainty Analysis of Response to Nutrient Loading Using a Mechanistic Eutrophication Model

摘要

Eutrophication modeling of the Neuse River Estuary was conducted using a modifiedversion of an existing two-dimensional, laterally averaged model (CE-QUAL-W2). The calibrated model was used to predict the water quality improvement in the estuary associated with a 30% reduction in riverine loading of inorganic nutrients. Three cases were examined: (1) reduced inorganic nitrogen, (2) reduced inorganic phosphorus, and (3) reduced inorganic nitrogen and phosphorus. Water quality improvement was quantified by comparing the predicted chlorophyll-a and dissolved oxygen concentrations for the nutrient reduction scenarios to a case without nutrient reduction. An uncertainty analysis was also performed to investigate the feasibility of the method and to quantify the uncertainty of model predictions. The uncertainty analysis examined only model specification error, using a regional sensitivity method, for a small subset of the model parameters that were considered to be important to quantifying phytoplankton growth.