Evaluation of Flood Risk in South Korea Through Time Series Analysis of Precipitation Data

The recent increase in extreme and intense rainfall events is a pressing concern, mainly due to the effects of climate change. These heavy downpours contribute significantly to urban damage, triggering floods, landslides and other related disasters. Such natural disasters pose serious risks to human life and infrastructure. Seoul, South Korea, is particularly vulnerable. In 2001, for example, the city recorded a staggering 273 mm of rainfall in a single day. More recently, in 2011 and again in 2022, Seoul suffered extensive urban flooding. These events were largely due to the inability of rivers and stormwater systems to handle the sudden deluge, which exceeded the design frequencies that these infrastructures were originally built to withstand. As climate change accelerates, the frequency of such extreme weather events is expected to increase, requiring advanced research to fully understand their impact on urban infrastructure. This includes vital structures such as dams, embankments and stormwater pipes, all of which require robust designs to cope with such unprecedented environmental stress. This study focuses on collecting and analysing rainfall data from meteorological stations across Korea. By using the Generalised Extreme Value (GEV) distribution along with time series analysis, our research aims to meticulously map flood risk patterns. These statistical methods are crucial for understanding and predicting the behaviour of rare but severe weather phenomena. In addition, our research calculates flood loads based on specific return periods and design frequencies. These calculations are essential for designing infrastructure that can withstand future climatic challenges, thereby ensuring the safety and resilience of urban environments against the increasing threat of flooding. This comprehensive approach not only highlights historically flood-rich or flood-poor periods, but also assists in the strategic planning and upgrading of urban infrastructure to cope with the realities of climate change.AcknowledgementThis research was supported by a (2022-MOIS63-002(RS-2022-ND641012)) of Cooperative Research Method and Safety Management Technology in National Disaster funded by Ministry of Interior and Safety(MOIS, Korea).