*Kanchana Kumari Mallika Achchillage¹、Tsuyoshi Wakatsuki²、Chiaki Oguchi³ (1.PhD student, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan、2.Chief Researcher, Storm, Flood, and Landslide Research Division, National Research Institute for Earth Science and Disaster Resilience, 3-1 Tennodai, Tsukuba, Ibaraki, 305-0006, Japan、3.Associate Professor, Department of Civil and Environmental Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan)