Abstract:

Using daily wind speed data of 61 stations with satellite-based station classification in Anhui province during 1981-2010, urbanization effects and contributions to the trends of annual and seasonal mean wind speed (Wa), maximum wind speed (Wm) and low wind speed (<2 m/s) days (Lwd) were analyzed. Both the annual and seasonal Wa and Wm presented significant decreasing trends, and Lwd showed significant increasing trends in Anhui province during recent 30 years. Especially, all the trends of Wa,Wm and Lwd at urban stations were obviously larger than those at suburban and rural stations, meanwhile, the trends at suburban stations were generally larger than those at rural stations. Due to the acceleration of urbanization in Anhui province after 2000, the differences in both Wa and Lwd between urban stations and rural stations were becoming bigger and bigger. The difference in trend coefficients of Wa between urban stations and rural stations was about -0.10 m/s per decade, and the corresponding urbanization contribution was about 40.0% to the total decreasing trends of annual Wa. For seasonal Wa, the largest contribution appeared in spring. The difference in trend coefficients of Lwd between urban stations and rural stations was about 15.58 d per decade, and the corresponding urbanization contribution was about 46.9% to the total increasing trends of annual Lwd. For seasonal Lwd, the larger contributions mainly appeared in autumn and winter. The effects of urbanization on Wm were generally insignificant.

Key words: urbanization effect, wind speed, contribution rate, Anhui province