Abstract: Based on the monthly average wind speed, maximum wind speed, average temperature data of three meteorological stations (Huanxian, Kongtong, Xifeng) in Longdong of Gansu from 1960 to 2014, the temporal and spatial variation characteristics of the wind speed and its influencing factors in Longdong was analyzed by using correlation analysis, Mann-Kendall mutation test and wavelet analysis methods. The results showed that the annual average wind speed had decreased by -0.09 m·s^-1·10a^-1 from 1960 to 2014, and had rapidly decreased during the period of 1973 to 1984, while entered a stable period of volatility after 1995 in Longdong. The average wind speed was the maximum in the 1960s, and it was the minimum in the 1980s. The rapid decreases of the daily maximum wind speed and the frequency of wind speed over grade 4 made great contributions to the decreased annual average wind speed. The seasonal average wind speed decreased at all three stations, and such trend was the most significant in spring and winter. The fluctuation of wind speed in spring played a predictable role in the fluctuation of wind speed in the other three seasons. The seasonal wind speed in spring (maximum) and autumn (minimum) played a most significant role in annual average wind speed. The average wind speed all decreased at all three stations, and the decreasing speed was gradually decreased from Huanxian, to Xifeng, and to Kongdong. The annual average wind speed had a first main cycle of 26 years, and it began to mutate in 1973. Huanxian and Kongtong were the earliest and the latest station of mutation respectively. The annual average wind speed was negatively correlated with the annual average temperature. The fastest warming occurred in spring and winter, and the reduction of wind speed in these two seasons was also the maximal among the four seasons.

Key words: fluoride, remediation technology., soil, speciation