The study of the non-engineering measures on the coastal protection in Taiwan

Wei Po Huang, Lien-Kwei Chien, Yen Hsuan Tsao

Friday 3 july 2015

13:30 - 13:45h at Africa (level 0)

Themes: (T) Managing deltas, (ST) Adaptive delta management

Parallel session: 16K. Managing deltas - Adaptive delta management

Taiwan is on the major routes of typhoon activities in northwest Pacific. When a typhoon approaches the coast, the strong wave energy combined with surge increase the probability cause coastal hazard. In the past, the authorities were focused on the coastal defenses renovation to protect people’s lives and livelihood due to the limiting budget and easy to execute. However, under the threat of the climate change, the coastal defenses are more or less insufficient for the increasing intensity of the extreme marine climate and the sea level rise. Considering the economic benefit and sustainable use, the defenses cannot be built infinitely. The integrated risk assessment and management of the coast region should be drafted to mitigate and adapt the change. The outdated idea of “Preventing coastal disaster” should be modified as “Allowing risk burden under the assessed standard”. This study is aimed at the assessment principle of coastal protection levels and non-engineering measures. In order to consider the properties of different coastal environmental condition, the coastal risk assessment was adopted to provide the reference of the designated risk levels and the draft of related non-engineering protection guideline. On the other hand, the coastal area of Yunlin County and Kaohsiung City of Taiwan were selected to identification of the suitable of assessment principle of coastal protection levels and proposed guidelines. In this study, the 50-year return period typhoons waves and tide elevation were used to check the safety of the protection facilities. Types and potential risks of coastal hazard, population density, average income and the land urbanization are the factors adopted for the risk assessment. Two coastal areas, Yunlin County and Kaohsiung City were classified as high and medium risk level respectively. The non-engineering measures were drafted including (1) Delimiting the buffer zone; (2) Construction of the hazard maps; (3) Land use modification (4) Buildings renovation and (5) Community-based hazard reduction. The more sustainable set of options are offer several recommendations for consideration in the coast area of Yunlin County and Kaohsiung City.