Inundation Analysis of a Coastal Urban Area using SWMM Model

초록

Recently, inundation of urban area has occurred frequently by the localized rainfall and flash floods in Korea. This may be due to the climate change and urbanization and so flood damage is also increasing. In particular, the coastal urban area has a drainage system which shows shorter travel time than inland watershed and is influenced by tidal water level. Therefore, this study performed the inundation analysis of a coastal urban area considering tidal level, rainfall, and urban drainage system. The part of Changwon city called Masan city is a typical coastal urban area in Korea and the severe coastal flooding was occurred in this area by a typhoon, Maemi in September 2003. At that time, daily rainfall was 157mm lower than the design rainfall of Changwon sewer system. However, the tidal wave caused by a typhoon was 4.39m to exceed the predicted value and this was due to overlapping the high tide of the coastal area with heavy rainfall and severe flood damage was occurred at that time. Therefore, in this study, flood inundation analysis will be performed by using the XP-SWMM model which is a one-dimensional urban flood analysis model. We will do inundation analysis of a coastal urban area with and without tidal level and compare these two cases. Say we will check flooding of coastal urban area under the conditions of sea level and rainfall.