WAQUA/TRIWAQ is a software system for the simulation of coastal waters. It is used by the Dutch ministery of public works and transport for the management of the waters in and around the Netherlands.
WAQUA/TRIWAQ used to have a built-in RRSQRT filter but the high complexity of the mixed simulation/data-assimilation code made it difficult to manage. The built-in filter has been replaced by a coupling to OpenDA. This eases the maintenance significantly and also allows the use of different data-assimilation methods. The performance of the new configuration is only marginally lower than that of the original implementation. The Domain decomposition and parallel computing facilities of WAQUA/TRIWAQ can be accomodated by OpenDA.
OpenDA was also used for calibrating the WAQUA model for the north west European shelf area. In order to obtain better predictions for the water levels at the coast, a correction was placed on the bathymetry in the model. The best value for this correction was found using the DUD method that is available in OpenDA. More about this calibration effort can be found in the flyer.