珠三角地区台风条件下不同时距风速的换算关系

[目的] 为全面了解台风条件下的不同时距风速换算关系，并为珠江三角洲沿海地区各类电力工程的设计风速评价复核提供依据。 [方法] 利用海岛气象站1991—2009年间共计14次登陆热带气旋影响期间的3 s、10 min、1 h平均风速资料，统计了3 s与1 h平均风速，以及10 min平均与1 h平均风速之间的阵风系数，并分析了上述阵风系数随平均风速、风向以及台风路径的变化情况，在此基础上确定了不同时距风速的换算关系。 [结果] 结果表明：阵风系数与平均风速和地表粗糙度关系密切，对台风路径不敏感。阵风系数随平均风速的增大而逐步减小并稳定在一定范围内；离岸风倾向于比向岸风出现更大的阵风系数。 [结论] 研究成果验证了世界气象站组织推荐的阵风系数取值在珠三角沿海地区具备适用性。

Conversion Relationship of Different Time Interval Averaged Wind Speed for Tropical Cyclone in Pearl River Delta Coastal Area

[Introduction] The paper aims to investigate the conversion relationships of different time interval averaged wind speeds in tropical cyclone and evaluate extreme wind speed of electric projects. [Method] Wind speed records from an island meteorological station in Pearl River Delta during 14 samples from 1991 to 2009 were employed to calculate gust factor between 3 s, 10 min, 1 h wind speed and effects of wind speed, terrain roughness, and typhoon track were analyzed. [Result] Results show that gust factor gradually decreases and approaches to a certain range when corresponding mean wind speed increasing while statistical distribution of gust factor is relatively insensitive to typhoon track. Offshore wind appears higher gust factor than onshore wind with different roughness. [Conclusion] This work supports the availability of recommended values from World Meteorological Organization in Pearl River Delta coastal area.