Prediction of Water Quality of Huangpu River Using a Tidal River Network Model

The Huangpu River is the largest river in Shanghai. It exerts great influence on this metropolitan due to the role of the metropolitan's largest drinking water source and the direct scenery waters bordering the venues of World Exposition Shanghai China 2010 (World EXPO 2010), so a series of water environment rehabilitation projects will be carried out during the eleventh five-year plan (2006–2010). The one-dimensional and two-dimensional coupling hydrodynamic and water quality model—RMA2 and RMA4—developed by the United States Army Corps of Engineers, was modified and applied to develop a Shanghai tidal river network model in order to assess the Huangpu River's water quality by 2010; in which the COD decaying rate, nitrification rate, BOD₅ decaying rate, sediment oxygen demand, and re-aeration rate were calibrated. The calibrated results of these coefficients were 0.10–0.25 d⁻¹, 0.03–0.07 d ⁻¹, 0.10–0.15 d ⁻¹, 1.0–10.0 g m ⁻² d ⁻¹, and 0.15–0.20 d ⁻¹, respectively. According to China's National Surface Water Quality Standard with class II–V, it is predicted that water quality of four main constituents—COD, BOD₅, NH₃-N, and DO—will be improved from class III–V in 2005 to class I–III by 2010, and the DO concentration between 5–7 mg L ⁻¹.