For general information, see the ADCIRC site, ADCIRC FAQ, or the ADCIRC Wikipedia page. For model documentation not yet available on the wiki, see the ADCIRC site. New content is being continuously added to the ADCIRCWiki, and material from the main ADCIRC site will be gradually transitioned over to the wiki.
IM is an important parameter in the fort.15 file that defines numerical model formulation and dimension. Among other things, IM specifies whether ADCIRC is 2D or 3D, solution of the governing equations is implicit or explicit in space, and whether the model formulation is barotropic or baroclinic.