In this study, simulation technique with multi-dimensional model(EFDC), coupled with COSFIM and FLDWAV, has been
applied to the upstream and downstream of weirs for hydraulic characteristics analysis through development of system and
was performed for 8 multi-function weirs on Nakdong river using developed system. COSFIM, FLDWAV and EFDC can
utilize suitable model in situation because they have pros and cons according to practical use purpose. Developed technique
can offers spatial and grid unit information as well as line and section unit information from 1-D modeling. It is considered
that the coupling simulation technique can provide useful hydraulic information for river management and treatment.