Model Development for Drinking Water Security in Tidal River, Case Study: Minjiang River, Southeast of Fujian, China

This paper presents a hydrodynamic and water quality modeling system for Fuzhou Section of the Minjiang River. Historical water quality monitoring and pollution surveys show that lots of water pollution sources were located close to the protection zone of drinking water sources of Fuzhou City. To obtain quantitative knowledge about the water environment in Fuzhou section of the Minjiang River and protect the drinking water source, an integrated modeling system was developed based on environmental fluid dynamics code (EFDC) and water quality analysis simulation program (WASP) modeling framework. The EFDC was used to simulate hydrodynamic in the river, and the resulting flow information was incorporated into the WASP to simulate the balance of dissolved oxygen. Using data in different hydrological conditions, model calibration and model validation were conducted in this paper. Three scenarios of water environmental management were designed in this paper. Scenario analyses were conducted using the developed model system to evaluate the water quality variations influenced by pollution sources. The results indicate that the tide downstream has a distinct influence on the hydrodynamics, there is a weak diffusion condition during the process of pollutants on migration in the tidal reach, and the model will provide an effective tool to ensure drinking water security.