1. International Research Institute of Disaster Science, Tohoku University , 468-1-E304 Aoba, Aramakiaza, Aoba-ku, Sendai 980-0845, Japan
2. Hydrologic Engineering Center, US Army Corps of Engineers , 609 Second St., Davis, CA 95616-4678, USA
3. Department of International Development Engineering, Tokyo Institute of Technology , 2-12-1-S6–3 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
4. International Research Institute of Disaster Science, Tohoku University , 468–1 Aoba, Aramakiaza, Aoba-ku, Sendai 980-0845, Japan