Abstract: Taking the year of 2000 as an example, the ocean waves in the sea adjacent to Zhejiang were simulated using SWAN model, and the wave power was calculated. Firstly, average annual and monthly wave power distributions were analyzed. The results show that the wave power is about 2~6 kW·m^-1 in the sea adjacent to Zhejiang,and increases seaward. Due to the effect of monsoon its seasonal variation is obvious far from the coast while it is not so obvious near the coast. Secondly, through analysis of wave joint distribution of wave height and period which corresponds respectively to wave occurrence frequency and wave power, we compare the wave power joint distribution of wave height and period in the sea area of northern,middle and southern Zhejiang. A parameter of ‘wave power ratio’ was introduced, which represents the proportion of cumulated wave power during one year within a range of wave height and period. Generally, the wave height and period range of big‘ wave power ratio’ and high wave occurrence frequency is very close but not completely the same. The range of big ‘wave power ratio’ and high wave occurrence frequency are relatively close in the sea area of northern Zhejiang,but the corresponding mean wave power is comparatively low, while the corresponding mean wave power of the rang of big ‘wave power ratio’ in the sea area of southern Zhejiang is high, but a little bit different from the range of high wave occurrence frequency. The situation in the sea area of middle Zhejiang is in between that off northern and southern Zhejiang. In general,there are abundant wave energy resources off Zhejiang, and the yearly wave occurrence frequency of exploitable wave energy is quite high.

Key words: SWAN, wave energy, wave power, joint distribution, Zhejiang offshore