Abstract
The interaction between ocean and river is very complicated topic since this area contains a lot of different processes. Of which the wave setup at a river entrance or tidal inlet due to an extreme event such as low pressure system and typhoon is a big concerning issue nowadays in terms of river mouth morphology change, saline intrusion, and navigation transportation. The main purposes of this study are to in-depth investigating the wave set-up at different morphological river entrances or tidal inlets based on collected data sets from 8 river entrances. Wave setup height is inversely proportional to water depth at river entrance. The more water depthis, the less wave setup will be obtained. Wave setup height was attained to from 10 to 15 percent of offshore wave height for the cases of narrow and shallow river or inlet mouth, and from 2 to 4 percent of offshore wave height for a deep and wide river.
