Numerous random wave trains are simulated based on the JONSWAP spectrum using the Longuet-Higgins wave model, and then extreme waves are investigated based on the wave trains with stable probabilities of freak waves. The probabilities of freak waves are smaller than those of based on Rayleigh distributions. With the spectra narrower, the probability of freak waves increases. During the fixed times, the frequency of freak waves obeys the Poisson distribution and time intervals satisfy exponential distribution. The most probable occurrence frequency of freak waves decrease and intervals of freak waves are longer with the spectra wider. Wave groups are discriminated based on wavelet spectra and their characteristics are analyzed. There are no more than four freak waves in wave groups. The probability of wave groups containing merely one freak wave is the largest. Numbers of freak waves in wave groups are increasing with the spectral narrower. Furthermore, time lengths of wave groups containing freak waves satisfy Generalized extreme value distribution (GEV distribution), and with spectra narrower, the most probable lengths of the wave groups increase.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |