太湖北岸风浪谱的特征分析

利用１９９２年在太湖北岸马迹山地区测得的浅水风风浪资料，采用ＦＦＴ方法求算风浪频谱，对谱结构特征的分析表明，观测到的风浪谱在平衡范围谱值按－４．０幂指数衰减，风浪谱形状与文圣常给出的理论结果比较接近。另外，分析以风要素为参量得到的无因次化频谱可以看出，观测谱基本满足谱的相似律。

ANALYSIS OF THE WIND WAVE SPECTRUM CHARACTER IN THE NORTH BANK OF TAIHU LAKE

A wave height instrument for obtaining wind wave data was plaeed about1.5m below water surfaee and 50m from the bank of Taihu Lak in Majishan district,Wnd in 1992. The sampling time was 0.1s and the observed mean wave height wasabout 30cm, the mean cycle time was about 2.0s. During the wave observation, wind direction and speed were also observed With an electrolytic wind instanent plaeedlom above the ground' The wind data computed and analysed in thig study werebasically short-distanee wind range and long-time constant Wnd direction data, Analysis of wind wave spectra comPuted with FFT method show that: 1) the spectrum curves are more narrow and steeper than that of P-M spectra observed in the oceanarea; 2) the spectrum value in the balanee rang decreases according to a -4.0 powerexponential funtion; 3) the spectnnn outline is sindlar to tha in the theory proposedby Wen Shengchang; and 4) the observed spectra obey the analogous law of windwave spectra.