Main content area

A comprehensive disaster impact assessment of extreme rainfall events under climate change: a case study in Zheng-wen river basin, Taiwan

Wu, Tingyeh, Li, Hsin-Chi, Wei, Shaio-Pin, Chen, Wei-Bo, Chen, Yung-Ming, Su, Yuan-Fong, Liu, Jen-Jih, Shih, Hung-Ju
Environmental earth sciences 2016 v.75 no.7 pp. 597
atmospheric pressure, case studies, climate change, coasts, disaster preparedness, disasters, landslides, mathematical models, meteorological data, rain, risk, rivers, sea level, sediments, typhoons, watersheds, Taiwan
This study ascertains the disaster impacts of extreme rainfall events at the river basin scale. Several numerical models were employed, including TRIGRS for shallow landslide, Flo-2D for debris flow, SOBEK for flooding, and FVCOM for coastline disasters. The connection between numerical models was determined by the input and output data of the scenario. The worst case was selected as the extreme event, i.e. the typhoon event with the most rainfall at the end of the century (2074–2099). Climate change data, including rainfall data, the return period of rainfall events, air pressure, tide data, and sea level were generated after bias correction for the disaster assessment. A river basin with a reservoir was selected as the study area and disaster potential was separately shown for upstream and downstream areas. All disaster impacts are represented on a river basin scale. The result shows that more sediment will affect mountain ways and a large volume of sediment will enter the reservoir. The reservoir is not affected because it has sufficient capacity. The most severe flooding will occur at parts where the main river curves, which are also key areas of mitigation. Finally, the coastline area is at low risk due to the far typhoon track. This result highlights key areas where disaster prevention measures should be implemented during a severe rainfall event.