中文摘要：

利用河西地区15个气象站点1961～2010年月平均风速和最大风速日值资料，采用M-K突变检验、ArcGIS中的IDW插值和小波分析等方法分析河西地区平均风速的时空变化趋势。结果表明：近50a来，河西地区年平均风速呈明显下降趋势，其递减速率为0．14m／（s·10a）（a=0．001）：该地区四季平均风速均呈减少趋势且减少趋势相同；平均风速的变化在空间分布上存在差异，具体表现为年平均风速的递减趋势是自西向东逐渐减小，瓜州和玉门是该地区减幅最大的区域，而乌鞘岭却呈现出微增的趋势；风速的长期变化具有一定的突变性，其年平均风速在1985年发生突变；该地区平均风速存在存在多尺度的周期结构特性，其变化周期为6、19和25a。

英文摘要：

Hexi area is characterized with a vulnerable ecological system and severe soil erosion in the north- west of China. Analyzing the trend of the average wind speed is critical for wind resources management and soil erosion control in this region. Based on the monthly average wind speed of the 15 weather stations in Hexi area from 1961 to 2010 and using the methods of climate trending rate, 5 years running mean tread, Inverse Distance Weighted interpolation, Mann-Kendall abrupt change test and wavelet analysis method, the spatial and temporal trends of the average wind speed as well as the possible influential factors were analyzed in Hexi area of Gansu Province from 1961 to 2010. The main results are as follows： 1） The annual average wind speed was 2.9 m/s in Hexi area. The annual average wind speed obviously decreased at the rate of approximately 0.14m/（s · 10 a） （a=0.001） in Hexi area during the period of 1961-2010. Furthermore, on the seasonal scale, the decreased rate of four seasons was similar. The mainly reason why the annual average wind speed decreased significantly was that the frequency of 5 or more than 5 levels of wind have decreased over recent years. 2） This trend has different spatial distribution in Hexi area. The average wind speed decreased significantly in the whole region and different subregions in recent 50 years, the decreasing rate in Guangzhou County and Yumen City were the biggest and the smallest one was in Wushaoling area. 3） Abrupt change was found in the long-term climate variation. The Mann-Kendall abrupt change test showed that the year of 1985 can be viewed as turning point of the abrupt change on an annual wind speed basis. While from the perspective of seasonal wind speed, the abrupt change points in summer and autumn appeared slightly earlier than those in spring and winter. The abrupt change of the average wind speed happened in 1985 in summer and autumn while that of spring appeared in 1987. The abrupt change of winter happened in 1986. 4） Morlet wavelet ana