博士 國立成功大學 水利及海洋工程學系碩博士班 101 Regarding the effects of rivers and seas to river drainage, the flood modeling usually assumes that the water of the rivers and seas does not invade to the internal water, or calculate the river/sea effect separately. However, the assumption is against the truth, and therefore cannot reflect the hydrodynamic phenomena of the coastal low-lying areas when experiencing drainage difficulty resulted from water surging at the sea estuary during the typhoons or storms. Consequently, it is necessary to simulate the river hydrodynamic with storm surge level derived from external and internal water coupling. In recently years, the severe Climate Change has caused extreme rainfall and frequent floods that seriously threaten coastal low-lying areas. It is not enough for old riverbank safety protection and river management to only focusing on embankment structure or river management itself. It is necessary to consider the interaction of river adjustment and external water from the seas through