Potential Performance Assessment of Coastal Urban Sewer Network according to Sea Level Rise

The rise in sea levels due to climate change causes a decrease in the discharge capacity of sewer pipes and an increase in the risk of urban inundation due to the encroaching of outfall to the coast. Therefore, it is crucial to quantitatively evaluate and predict the increasing degree of risk to properly respond to the risk of inundation that is aggravated by the effects of rising sea levels. In this study, two research areas were selected in consideration of the regional characteristics of the coastal area and the sea level rise scenarios. In the selected research areas, the performance of the sewer network was quantified through a reliability technique. Accordingly, the change in the Disaster Prevention Performance Target Rainfall according to the sea level rise was analyzed and reevaluated. The results showed that the target rainfall for disaster prevention performance by rainfall duration in Wando was 35.6% to 41.7% and in Sacheon, it was 36.7% to 67.5% under the influence of the approximate highest high water. This study presented a plan to adjust the target rainfall for disaster prevention performance, which should be raised in consideration of the sea level rise to meet the current target rainfall for disaster prevention performance. In response to the flood risk of coastal cities increasing due to rising sea levels, the results of this study are expected to serve as basic data to establish disaster reduction strategies for coastal cities.