Flood Damage Estimation of Coastal Area Considering Climate Change

Abstract:

There are various researches to respond to the natural disasters efficiently such as floods caused by climate change. Most of the studies have assessed the impact of climate change on floods by the increase of future rainfall and the sea level rise separately. However, we have to consider the effects of the combined floods by future heavy rainfall and sea level rise. This means the urban floods in coastal area can be occurred due to the combined inundation by overflow of urban drainage system and by sea level rise. Then we can estimate the flood damage from the combined floods due to the climate change.

Hence, this study selected Taehwa River basin, Korea which flows from the west to the east and extends to Ulsan bay. This study analysed on the influence of hydrologic alteration in the coastal area by considering the sea level rise as well as the future precipitation according to climate change. It is prepared the flood inundation map which is related to the increase of precipitation and sea level for assuring how the sea level rise effects on the coastal area caused by the climate change, and the flood damage assessment is estimated to compare the hydrologic alteration quantitatively.

The study result showed that flood level in the channel flows to the mouth rose as the water surface elevation rose due to the rise in sea level. In addition, the extent of increase in flood level caused by sea level rise was greater at a location nearer the outlet and it was smaller at a place farther from the outlet. It could be verified that the change of the inundation depth and damage area caused by the rise in sea level can have an effect on the flood damage assessment. It is important factor to analyse not only the increase of precipitation cuased of climate change in coastal rivers but also the change of rise in sea level, the flood water level, the flood inundation and the flood damage assessment. The result of this study could be used as basic data for creating technology that would assess the flood vulnerability of coastal urban regions and evaluate preventive measures for coastal disaster risk.

Acknowledgements

This work was supported by the National Research Foundation of Korea (NRF)grant funded by the Korea government (MEST) (No.2011-0028564).