2003 Fiscal Year Final Research Report Summary
Estimating the Parent Distribution of Storm Type-Separated Annual Maximum Wave Height on the Northwestern Pacific Ocean
| Project/Area Number |
14580506
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Natural disaster science
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| Research Institution | Ehime University |
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Principal Investigator |
YAMAGUCHI Masataka Ehime Univ., Faculty of Eng., Prof., 工学部, 教授 (60027266)
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| Project Period (FY) |
2002 – 2003
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| Keywords | wave extremes / parent distribution / typhoon-generated waves / low-generated waves / Monte-Carlo simulation / wave estimation / measurement data / the Northwestern Pacific Ocean |
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| Research Abstract |
This study produces a large size sample of storm type-separated annual maximum(AM) wave height data through a Monte-Carlo simulation of typhoon-generated waves over 20,000 years or low pressure system(low)-generated waves over 10,000 years on the Northwestern Pacific Ocean including the Japan Sea and the East China Sea, and estimates a parent distribution based on the extreme value analysis for each of the AM wave height data sets. Also, the availability is investigated through the comparison with the return wave heights and their ratios similarly evaluated for historical typhoons in the past 50 years and for historical lows in the past 20 years. Main results are summarized as follows.
1.The distribution of 50-year return wave height is in qualitative and quantitative agreement with that estimated for each type of the historical storms.
2.The parent distribution of typhoon-generated AM data is approximated with the Weibull distribution, in which the shape parameter tends to decrease from around 4 on the southwestern area toward around 1.4 on the northwestern area and on the northeastern area. On the Japan Sea, the shape parameter decreases from Japan side toward the continent. For the case of low-generated AM data, the shape parameter decreases semi-circularly from a value of 2 on the eastern area, and the Gumbel distribution is selected on the wide area around Japan.
3.The parent distribution of storm type-free AM data is strongly affected by predominant storm-separated AM data.
4.A sample of R-year return wave height is highly approximated with the Weibull distribution, and the greater the ratio of return period to sample size is, the smaller the value of shape parameter becomes. This means a longer tailing of the sample distribution with increase of the ratio.
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Research Products
(4 results)
