In this study, focusing on buildings as the smallest unit of urban space, the distribution characteristics of risk factors were examined by building use as an adaptable measure for urban flooding disasters. Flood risk is calculated as a function of hazard, exposure, and vulnerability. The flood risk for a building was classified into five classes, and the distribution characteristics of buildings were examined according to England’s flood risk vulnerability classification system, known as Planning Policy Statement 25 (PPS25). After analyzing the risk of flooding in Ulsan Metropolitan City, one of Korea’s representative urban areas, it was found that while Dong-gu District can be considered relatively safe, districts of Jung-gu and Nam-gu, as well as Ulju-gun, have highly vulnerable buildings with red and orange ratings, which include motor vehicles-related facilities, education and welfare facilities, and residential facilities. There has been evidence to prove that urban flood disaster affects topography and the environment, in addition to having a significant effect on adaptability depending on the facility groups that resulted from urbanization. This study is expected to serve as a scientific database for disaster risk reduction and climate change adaptation to floods during land-use planning, which would eventually allow for systematic management of high-risk buildings through verification of location suitability of buildings by facility group.

Climate change caused by global warming has resulted in an increase in average temperature and changes in precipitation pattern and intensity. Consequently, this has led to an increase in localized heavy rain which intensifies the uncertainty of the development of urban areas. To minimize flood damage in an urban area, this study aims to analyze the flood risk effect on buildings by ranking the risk of flood damage for each building type and sorting the long-term land use plan and the building type that requires particular consideration. To evaluate the flood risk of each building type, vulnerability analysis and exposure analysis were conducted in five regions of the Ulsan City. The vulnerability analysis includes determination of each building type by using the building elements which are sensitive to flood damage. In terms of the exposure analysis, environmental factors were applied to analyze the flood depth. The mapping based on the results from two analyses provided the basis for classifying the flood risk into five classes (green, yellowish green, yellow, orange, red). The results were provided in the urban spatial form for each building type. This analysis shows that the district near the Taehwa river is the area with the highest risk class buildings (red and orange class buildings). Notably, this area plays a pivotal functional role in administrating the Ulsan City and has a high density of buildings. This phenomenon is explained by city development which is centered around the lowland; however, given the high value of property, the potential risk is proven to be high.

This study assessed the flood risk in the Republic of Korea, considering representative concentration pathway (RCP) climate change scenarios, after applying the concept of “risk” as proposed by the Intergovernmental Panel on Climate Change. For the hazard assessment, hazard indicators were constructed utilizing design rainfall standards, which represented the local flood protection capability, as a flood threshold. We constructed high-resolution spatial images from data of buildings, roads, agriculture areas, and the population that have suffered significant flood damage in the Republic of Korea. We also calculated flood exposure levels by analyzing the scales of the targets in low-lying areas. Environmental and anthropogenic conditions that can directly increase or decrease river flooding and urban flooding were set as indicators and utilized as proxy variables. As a result of the risk assessment, we found 43 risk areas in the historical period, accounting for 19% of the total administrative districts, 42 in the projected period under RCP 4.5 (18%), and 51 in the projected period under RCP 8.5 (22%). This study’s results can be utilized by the central government to determine flood risk priority areas in various administrative districts and by the local government to select priority areas to install flood reduction facilities.

This study applies the concept of risk defined by IPCC's fifth assessment report to Daegu City, Ulsan City, Gyeongsangbuk Province, and Gangwon Province to assess and analyze snow disaster risks. Sub-indicators of three hazards, six exposures, four vulnerabilities, and five adaptive capacities were selected, and spatial information based on grids or administrative districts was constructed. The weight of each indicator was calculated with the Analytic Hierarchy Process (AHP), and the maximum inconsistency of the expert survey result was 9.86%, indicating high consistency. The results show that administrative districts with an space average risk of "very high" are Ulleung, Gangneung, Sokcho, Yangyang, Pyeongchang, Goseong, Donghae, Samcheok, and Jeongseon, accounting for 16.7% of the entire administrative district. One region has a "high" risk, Taebaek (1.9%), and those with a "moderately high" risk were Uljin and Inje (3.8%). These regions have very high levels of hazards, very low exposure, very high vulnerability, and low adaptive capacity; hence, hazard, vulnerability, and adaptive capacity had a significant effect on the increased risk. Pyeongchang had the highest standard deviation of gridded risk among the 12 regions with a risk above moderately high. The standard deviation of gridded risk for Pyeongchang was estimated to be 1.0 with the highest value, followed by Inje, with 0.69, and Jeongseon, with 0.55; therefore, differentiated climate change adaptation measures should be established according to gridded risks.