碩士 / 國立臺灣海洋大學 / 河海工程學系 / 102 / The purpose of this paper is to explore the safety of the seawall,which are located in Yunlin and Kaohsiung coast, under Climate Change. To assess the safety of these seawall, it need to calculate the overtopping of each seawall, and analysis the value of overtopping if that will exceeds the permissible value or not. In order to get the wave high of each seawall, numerical methods was used in this study. The used numerical methods in this study was mike 21 which was introduced from Danish Hydraulic Institute (DHI) in Denmark. Mike 21 has many different type of simulation modules, in this study it just used the Spectral Waves and Hydrodynamic modules which are calculating the wave and the storm surge.
As the moving speed of the typhoon would make Taiwan typhoon persistence over time to increase or decrease, thus increasing the typhoon wave height and wave action time, the impact on the coast have increased, typhoons forward speed used in this study were under the course of an average return period of typhoon moving speed of 50 years, as well as climate change scenarios Typhoon pressure on average moving speed of analysis to reproduce the corresponding.
In this study, typhoon intensity is using the 50-year return period of pressure and wind speed, analyzing from typhoon data. Typhoon intensity under climate change is based on the results of previous studies, and get together the intensity of 50-years return period typhoon and the fittest enhancement values of wind speed and pressure. The typhoon data of this study are using from Central Weather Bureau(CWB) and National Institute of Informatics (NII) in Japan. The return period analysis was using normal distribution, log-normal distribution, extreme value type III distribution, Pearson and log-Pearson type III distribution to produce the distribution of five kinds of regression analysis, and calculated the standard error(SE) and error sum of squares(SSE) by Hazen and Wilbur method. And using the smallest error as the final results of the analysis .
In the part of water level, for the use of wave file simulation and overtopping calculation, is integrated the mean high tide, storm surge and the sea level rise.
In the simulation of waves, in order to get the more accurate simulation results, the wave field simulation is divided into two sizes for large-domain and near-shore simulation. Dynamic boundary condition in large domain simulation used by the typhoon intensity of 50-year return period under climate change .
Using the overtopping method of Van der Meer, it can calculate the overtopping value with the result for wave field simulation. Comparing the permissible value with the overtopping value, it can assess whether the seawall safety or not. If the result of analysis is safe, that will do nothing for the seawall. If the seawall is in danger, then discuss the defence and strategy of the seawall and the coastal zone.
After the analysis of safety, all seawall in Yunlin and Kaohsiung coast are safety under the intensity of 50-year return period typhoon. In the extreme case of climate change, in addition to the shia-lun, shin-kang, yang-chou-tsuo, ching-han and tai-tzu-tsui seawall in Yunlin and tien-bau seawall in Kaohsiung are dangerous, the rest are safety. In terms of engineering and non-engineering protection shia-lun, shin-kang, tai-tzu-tsui seawall are suitable of riprap to enhance the seawall safety. For the seawall of ching-han and yang-chou-tsuo, as the result of relationship between position and back using, it should be protect with managed strategy or maintain the status quo.
For the tien-bau seawall in Kaohsiung, due to that without any building and development behind the seawall, so it doesn't require too much protection, only need to limit the possible development pattern to reduce the risk of disasters.
| Identifer | oai:union.ndltd.org:TW/102NTOU5192027 |
| Date | January 2014 |
| Creators | Huang, Shan-Hua, 黃少華 |
| Contributors | Huang, Wei-Po, 黃偉柏 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 120 |
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