강변저류지 월류부에서 월류제 또는 수문 형식에 따른 홍수저감효과에 관한 개략적 연구

Abstract

Abstract Construction of large-scale structures such as dams would be suggested actively to cope with change of flood characteristics caused by climate change. However, due to environmental, economic and political issues, dams are not ideally constructed. Thus flood damage reduction planning projects would get started including washland or detention pond for sharing the flood in basin. The washland made artificially by human being is an area of floodplain surrounded by bank to be intentionally inundated by overflowing through overflow structure adjacent to main channel during flood season. Flood reduction capacity at just downstream of each washland could be affected by type, length, and crest elevation of overflow structure in addition to shape of design hydrograph, storage volume of washland, etc.. In this study flood reduction effects of washland are estimated for overflow weir type and gate type to compare the results of flood reduction respectively subjected to given hydrograph in sample site, the Cheongmicheon stream. It has been shown that even if gate type at overflow structure could yield more flood reduction than overflow weir type, economic aspect such as initial cost, operation cost and maintenance cost should be considered to select the type of overflow structure because flood reduction rate by gate type could not be significant value from engineering point of view.