Author(s): Hyung-Jun Kim; Kwang Seok Yoon; Jin Woo Lee; Yong-Sik Cho
Keywords: Dam-break; Flood intensity; Urbanized area; Finite volume method
Abstract: Flood inundation due to dam or levee-break may cause serious damage to human lives and properties. To mitigate flood hazard, an accurate flood risk assessment is necessary. In many countries, flood risk maps are produced to show information about flood risk and vulnerabilities in a particular area. In many countries, they produce the flood risk maps using calculated inundation depth by numerical models which are discritized the one-or twodimensional depth averaged governing equations. However, water depth is not only important factor of flood risk. At near area of dam or levee, the velocity is an important factor of flood inundation. Therefore, the flood intensity, the product of water depth and velocity, is adopted to assess flood risk at the near inundation area of dam and levee-break point. Flood waves through urbanized area are affected by structures. For instance the structural obstruction in an inundation area to the flows induces a back propagation effect that will increase water depth over a long distance upstream. In this study, the changes of water depth, velocity and flood with various arrangements of structures are estimated using twodimensional numerical model. In numerical simulation, the finite volume model is employed to generate dam-break flows. The numerical model is verified by application some problems which have exact solutions and experimental measurements. To analyze the influence of structures, simple structures are built in the experimental channel. By changing the distance from reservoir to structures and gap between structures, the variation of flood characteristics are measured.