关键词: 波浪组成;风浪;涌浪;有效波高;太湖;

Abstract: Wave is the key dynamic process that drives the evolution of aquatic ecosystem in large shallow lakes. In this paper, the wave composition and its evolution characteristics were analyzed based on the observation data of wave direction spectrum, wind speed and wind direction in the northern coastal area of Taihu Lake. The results showed that the wave frequency spectrum in the near-shore area of northern Taihu Lake was mainly unimodal or bimodal, belonging to medium and high frequency wave. Wind is the main driving force for wave formation, and the modulation of wind direction or surrounding terrain on the significant wave height can be quantitatively characterized by trigonometric function. The relationship between the significant wave height, spectral peak frequency and its average direction of wind waves, and wind speed or direction confirmed that the wave in the northern coastal area of Taihu Lake were composed of surge and wind waves, and the surge proportion was relatively high. The reflection of the shoreline increased the surge proportion in the northern coastal area. The significant wave height of surge not only increased exponentially with the coupling wind speed (coupling of wind speed and wind direction), but also had the phenomenon of fast and slow differentiation. The research results can help to improve the accuracy of wave composition estimation in the near-shore area of large shallow lakes, and ensure the effect of aquatic ecological restoration.

Key words: wave composition; wind wave; surge; significant wave height; Taihu Lake