臺灣東海岸颱風波浪推算模式

Abstract

本文主要研究目的是利用統計迴歸的方法，來建立一個能即時 推算臺灣東海 岸颱風波浪的推算模式。 由蒐集到的颱風天氣與波 浪資料整理分析，以示性波法建立比 風波浪與颱風之經驗公式，此推算模式能免除 如 CERC所提僅能計 算颱風最大波浪特性及 Bretschneider(1976)之繁瑣計算，而 提供簡 便即時之推算。此迴歸之推算比風波浪的公式，與颱風特性之關係 為 Hs=1.3+a(dp/ 100)(1/(1+b*D/R7))(1-As) Ts=6.0+a(dp/100g)**0.5*(1/(1+b*D/R7)) 本文再利用極值統計分 析迴歸出各種重現期之波浪特性。以花 蓮港為例，求出重現期 50年的波高值約為 10.2~12.8公尺，偏差量 為0.8~1.6公尺之間。 ， 本文所推算出之波浪公式，因颱風波浪資料缺漏與不足，且局 部 於花蓮港之單點數據，可靠性稍嫌不足，且極值分析所選擇之樣 本僅28年，樣本數 尚少，應再做更深入且樣本數多之分析。 最後利用 VisualBasic 語言 ，設計一套簡單的波浪推算系統， 冀使工程應用上颱風波浪推算更為實用與方便。 Taiwan was infested with typhoons for 3.75 times per year by averaging the typ hoon data of Central Weather Bureau (CWB) from 1897 to 1992. Mosttyphoons land ed on or passedby the eastern taiwan. The induced large waves by typhoons shou ld do a severe impact on the coastal construction in the eastern Taiwan. It is important to establish a typhoon wave calculationmodel to estimate the typhoo n waves for the east coast of Taiwan. After relating typhoon waves to typhoon strength and distance between insterested point and typhoon, we proposed an i mperial formula for wave height and period in terms of information posted by CWB. Furthermore, the wave height of a return period will be available by usi ngthe extreme statistics proposed by Goda (1989). We chose Hualien harbor as a n example and found its wave height of different return period. The wave heigh t of 50-year return period is 10.2-12.8m with a deviation of 0.8-1.6mfor Huali en harbor. The wave calculation model was programmed in the Visual Basic Lang uage to facilitate to predict waves for convenient and obvious practice. A su ggestion that we should collect more typhoon waves and know more information o f Typhoon is given to future promotion for wave calculation model.