Development of RWQM1-based integrated water quality model in OpenMI with application to the River Zenne, Belgium

Descriptions of biochemical conversion processes based on QUAL principles have been used widely. We chose the recently developed IWA RWQM1 principles to model in-stream conversion of water quality components due to its sound physical background. An engine (a simulator) based on the RWQM1 principles was integrated with three other engine components—hydrological (SWAT), hydraulic (SWMM) and stream water temperature—in the OpenMI interface. We applied the integrated model to the River Zenne, Belgium. The results indicate that the integrated model can simulate various water quality components with a wide range of accuracy, from “Unsatisfactory” to “Very Good”. However, we could not validate the model against each of the RWQM1 components as most of the components were not measured in traditional river monitoring programmes.