Model Description

CCHE-WQ is a physical and bio-chemical process-based module which simulates the water quality variables and pollutant transport dynamically. It is based on the mass transport equation and can be coupled with CCHE2D and CCHE3D hydrodynamic and sediment transport models.

Main Features of CCHE-WQ

CCHE-WQ can be coupled with CCHE2D and CCHE3D to simulate the conservative substances or non-conservative substances in water flow. The impacts of environmental factors such as temperature, salinity, pH, etc. on the water quality processes are considered. CCHE-WQ can take different kinds of boundary conditions, such as multiple point sources; multiple non-point sources and time-varying flow conditions. It also can be applied to long-term and dynamic simulation.

Using CCHE-WQ, the properties of pollutant transport and mixing can be simulated and their concentration distribution in the horizontal and vertical directions can be obtained. For the water quality simulation, four interacting systems are implemented: phosphorus cycle; nitrogen cycle; phytoplankton kinetics; and dissolved oxygen balance. The concentrations of following state variables can be solved numerically: ammonia nitrogen(NH4), nitrate nitrogen(NO3), ortho-phosphate(PO4), phytoplankton(PHYTO), carbonaceous biochemical oxygen demand(CBOD), dissolved oxygen(DO), organic nitrogen(ON), organic phosphorus(OP), etc.

Application Examples of CCHE-WQ

CCHE-WQ has already been tested using analytical solutions and laboratory data. It is currently being tested using field data. The model is currently used to monitor the water quality in Deep Hollow Lake, which is a very shallow oxbow lake, in Northern Mississippi.

Simulation of pollutant dispersion in open channel flow