台灣近海波譜模式之研究

Abstract

以台灣近岸海域8個測站的長期波浪觀測資料，求出個別的波譜型態，並 利用Pierson-Moskowitz波譜、TMA波譜、WALLOPS波譜及郭所提出之有限 水深波譜來加以描述，並得知在各測站之Pierson-Moskowitz波譜的形狀 參數與波浪條件的關係並不佳，而TMA波譜僅有Phillip常數與波浪尖銳度 存在著特定的關係，且JONSWAP波譜並不適用於淺水波譜。將Pierson- Moskowitz波譜的形狀參數取平均值可得到地域性波譜模式，TMA波譜之 Phillip常數則與波浪尖銳度有關，因此求得其經驗公式，並將其他參數 取平均值代表，而得到TMA波譜模式。引示Pierson-Moskowitz波譜、TMA 波譜與實際海洋波譜做比較，並求變異係數之平均值，發現在模式波譜中 以TMA波譜最為接近實際海洋波譜形狀。此外，亦將Pierson-Moskowitz波 譜所發展出的地域性波譜及利用經驗公式的TMA波譜，與實際海洋波譜做 比較，並求變異係數之平均值，發現在這些理論（經驗）波譜中，以地域 性波譜模式最為接近實際海洋波譜形狀，而地域性波譜、TMA波譜模式皆 優於WALLOPS波譜及郭所提出之有限水深波譜。在地域性波譜模式之變異 係數平均值與模式波譜中的Pierson-Moskowitz波譜之變異係數平均值的 比較上兩者差距不大，而且地域性波譜模式並不需要任何的設計波浪的條 件便能決定，使用上亦極為方便，因此建議採用之。 By using the long-term observational information from the eight wave stations off the nearshore of Taiwan, and find the condition of indivdual wave. Using Person-Moskowitz spectrum, TMA spectrum, and the finite depth spectrum raised by Kuo to describe it. The relationship between the parameter of Person- Moskowitz spectrum in each wave station and the condition of wave is not good. As to the TMA spectrum, only Phillip's constant has special relationship with the wave steepness. And the JONSWAP spectrum does not fit in shallow water wave spectrum. Taking an average from the parameter of Person- Moskowitz spectrum can get the model of local wave spectrum. The Phillip's constant of the TMA spectrum has much to do with the wave steepness. It is found its experience formula, and take an average from the result and other constans and have the model of TMA spectrum. Person-Moskowitz spectrum and TMA spectrum compare with the real ocean wave spectrum and take an average of its covariance. The model's TMA spectrum is closest to the condition of the real ocean wave spectrum. Additionally, compare the local wave spectrum derived from Person-Moskowitz spectrum and TMA spectrum, which uses experience formula with the real ocean wave spectrum, getting the average of covariance. So it is found that among thesetheoretical ( or experience) wave spectrum, the model of the local wave spectrum is closest to the real ocean wvae spectrum; also the local wave spectrum and the model of the TMA spectrum are better than the WALLOPS spectrum and the finite depth spectrum raised by Kuo. There is little deffererce between the average of covarience of the model of the local wave spectrum anr that of the model's Person- Moskowitz spectrum . The model of the local wave spectrum can be decided wtihout any primary consideration of wave, and it is quite convenient to use; therefore it to be adopted.