The Climate Change of Flood and Debris mitigation after Typhoon Morakot 2009 in Taiwan
Professor TAN Yih-chi, Harold 譚義績 (NTU, Taiwan)
Abstract
The typhoon Morakot struck Taiwan during August 8-10, 2009, and the government statistics analyzed that typhoon brought a maximum of 3,004 mm rainfall in three days, and records of 21 rain stations were over 2,000 mm. The disaster claimed 673 casualties and 26 missing persons. Around 24,950 evacuees were evacuated by the Disaster Prevention and Response Act. The heavy and long period of rain storm also triggered multi-hazards, such as, flooding, debris flow and destructive landslides. The economic loss was USD 6.2 billion. This kind of damage was caused by extreme weather condition. We consider that future climate change will keep bringing huge impacts to everywhere all over the world. Those impacts are listed in the followings: change in biosphere, long-duration drought, severe floods triggered by extreme torrential rain, spatial change in homelands and food scarcity.
The extreme weather condition induced by climate change is the most direct factor influencing the occurrence of floods, e.g. the extreme rainfall increases discharge and inundation area, sea level and estuary water level raising induce overbank floods, and land-use abuse and land-slides trigger high concentration of sediment discharge and river bed aggradations.
This study aims at the settings of hydrological scenarios due to climate change, evaluation of hydraulic structures (e.g. levees), vulnerability and risk analysis, and adaption strategy and practices. The study focused on Kaoping River basin watershed. First, the hydrological scenarios due to climate change are set. Secondly, based on those scenarios, the hydraulic structures are evaluated. Thirdly, the vulnerability and risk analysis are performed. Last, adaption strategy and action plans are proposed by referencing to actions taken by the Netherlands, Japan and USA for improving the capacity of the hydraulic structures of this basin watershed.
About the Speaker
Professor Harold Yih-Chi TAN has completed his Ph.D from Cornell University in 1993. He is a Professor of the Department of Bioenvironmental Systems Engineering, NTU(Taiwan) and has over 30 years experience in the field. He is also the Director of Center for Weather Climate and Disaster Research (WCDR) in the same university.
Prof TAN's main research areas are groundwater, porous media flow, irrigation and drainage, disaster prevention and flood control. He has published more than 40 papers in reputed journals and serving in various editorial boards of numerous journals.
