應用衛星測高資料探討台灣外海波浪特性

Abstract

本文利用TOPEX、JASON-1、ERS-2、GFO-1、ENVISAT-1五顆衛星所提供1992-2006年之海象資料，分析示性波高和風速資料間的關係；並依據氣象局近海波浪預報區域之分區形式，將台灣週遭海域分為東北、東南、南部、西南、西北、北部六個區域，分析個別衛星在不同分區中之月平均逐年趨勢以及資料分佈與統計特性，進而比較不同區域中氣候發生異常的次數與示性波高間之特性與趨勢。 本研究有別於一般使用浮標資料來瞭解台灣海域的示性波高和風速的統計特性；近海浮標之波浪特性由於距海岸較近，無法代表外海波浪變化的情形。因此本文利用衛星資料以計算台灣外海之波浪特性，可發現台灣海域每年的示性波高平均變化有上升的趨勢，且其分佈近似於Gamma分佈，本文亦提出波高與風速之最佳二次迴歸式，以利後續工程上之應用。因此在往後在海岸工程的應用上除了可從波浪理論的推演來瞭解其特性外，亦可從利用衛星長期的觀測資料以歸納分析風浪的性質與趨勢。

The wave data in real sea are generally and traditionally collected by data buoys in the coastal zones to indicate the significant wave heights and wind in Taiwan for engineering practice and scientific researches. These data are applicable for coastal zones rather than offshore zones. In this investigation significant wave height and wind data around Taiwan waters for 1992 to 2006 from five satellites, that are TOPEX, JASON-1, ERS-2, GFO-1, ENVISAT-1, are collected to establish the relationship between both kinds of data. The monthly variations of significant wave heights and winds are statistically analyzed in six fishery zones around Taiwan based on the classification of central weather bureau. Furthermore, the yearly times and significant wave heights of abnormal climate are statistically analyzed. The mean monthly variations of both monthly wave heights and winds increase with time. The distribution of significant wave heights in each zone is Gamma function. The best fitting for the relationship between significant wave heights and wind is quadratic polynomial. The proposed results of collecting and analyzing significant wave heights and winds can be applicable for engineering use and examined for scientific researches.