• WRF-Hydro is a hydrological model developed by US NCAR (National Center for Atmospheric Research)

• WRF-HydroQual is a physically-based, spatially-distributed water quality model built to extend WRF-Hydro’s capabilities to simulate water flows and solute transformation and transport at various spatial scales

• WRF-HydroQual model is coupled with the WRF-Hydro model in two ways:

• Tight coupling (by embedded coding)

- Paddy field module

- Point source module

- Water abstraction and discharge module

• Loose coupling (by file sharing)

- Soil erosion and transport model

- Carbon cycling model

- Nitrogen cycling model

- Phosphorus cycling model

- Plankton model 

• Since 2022, the WRF-HydroQual model has been implemented for the Geumho River watershed and the Nakdong River watershed in South Korea

• Calibration and validation of the WRF-HydroQual model have been conducted, yielding results that demonstrate the model’s strong performance and capabilities

• Sediment transport (overland and channel)

  • 4 particle size classes: clay, silt, fine-sand, and coarse-sand

• Organic matter transformations and transport

  •  Carbon, nitrogen, and phosphorus in soil layers and water bodies

  •  Transformation equations solved by using the fourth-order Runge-Kutta methods

  •  Conceptual transfer functions used for transport processes

• Seasonal dynamics of plankton

  •  Zooplankton and phytoplankton dynamics in water bodies

• Anthropogenic effects

  • Inputs from fertilizers, manure, and point sources

  • Forced water distribution: abstractions and discharges