도심지 침수해석을 위한 건축물 밀집 지역 영향 분석

Analysis of the Impact of Building Congested Area for Urban Flood Analysis

최근 기후변화 및 도시화로 도심지에서 발생하는 홍수피해의 규모가 증가하고 있어 다양한 침수해석 기법이 필요한 실정이다. 2010년부터 연속적인 침수피해가 발생하고 있는 사당천 유역은 XP-SWMM을 활용하여 배수 개선 기본계획을 수립하고 침수방지 대책을 제시한바 있다. 하지만 침수해석 과정에서 도시의 건축물을 고려한 분석이 이루어지지 않아 침수피해 정도가 과대 산출되는 경향이 나타나는 문제가 발생하였다. 따라서 본 연구에서는 XP-SWMM을 활용하여 건축물을 고려하지 않았을 경우와 비활성 영역으로 지정하였을 경우를 비교·분석하였다. 연구 결과 건축물을 고려하지 않았을 경우 침수피해 면적은 271,000 m², 평균 침수심 0.15 m였으며 건축물을 비활성 영역으로 고려할 경우 172,900 m², 평균 침수심 0.32 m로 약 36% 정도 과소 추정되고, 건축물 주변의 유속은 1.62 m/s에서 1.83 m/s로 약 1.12배 증가한 것으로 분석되었다.

Recently, the scale of flood damage occurring in urban areas is increasing due to climate change and urbanization, so various flooding analysis techniques are needed. In the Sadangcheon Stream basin, which has been continuously flooded since 2010, a basic plan for improving drainage was established using XP-SWMM and measures to prevent flooding were proposed. However, in the process of inundation analysis, the analysis considering the city's buildings was not conducted, resulting in a problem that the degree of flooding damage tends to be overestimated. Therefore, in this study, XP-SWMM was used to compare and analyze cases where buildings were not considered and designated as inactive areas. As a result of the study, it was analyzed if the building was not considered, the flood damaged area was 271,100 m² and the depth of submersion was 0.15 m, and if the building was considered inactive area, the flood damaged area was 172,900 m² and the depth of submersion was 0.32 m that it is under-estimated about 36% and an flow velocity around the building increased from 1.62 m/s to 1.83 m/s about 1.12 times.