祁连山区风速和风向时空变化特征

Temporal and Spatial Variation Characteristics of Average Wind Speed and Direction in the Qilian Mountains,China

分析山地的风速和风向,对认识山地地区的气候变化和合理利用风力资源具有重要的意义。本文基于祁连山区11个气象站点的平均风速、最大风速和最大风速的风向数据,利用多种数学方法和ArcGIS空间分析法对风速和风向的时空变化分布规律作了探讨。结果表明:(1)祁连山区春季的平均风速和最大风速是年内风速变化的峰值区,其中中段和东段的最大风速出现在冬季。(2)全区的平均风速和最大风速年变化整体均呈下降趋势,下降率分别为-0.07和-1.56 m·s^-1·(10a)^-1。(3)1970—1979年风力资源最丰富;年际和季节(冬季除外)平均风速的突变均发生在1993年,东段和中段的平均风速均在1990—1999年发生突变,全区和各个区段平均风速的周期均为22a。(4)祁连山区平均风速自西向东呈递减趋势。(5)最大风速的风向以西南风为主,而东段则以偏东南风为主。

Research on wind speed and direction in mountainous areas play an important role in understanding climate change and utilizing wind resources rationally.Based on the records of average wind speed,maximum wind speed and direction collected at 11 meteorological stations in the Qilian Mountains,spatial and temporal distribution of wind speed and direction was analyzed by using multiple mathematical and ArcGIS spatial analysis methods.Main conclusions were as follows.First,average and maximum wind speed in spring were the highest in a year,and the wind speed in the middle and east segments reached maximum in winter.Second,inter-annual variability of average and maximum wind speed presented a downward trend with a variation rate of-0.07 and-1.56 m·s^-1·(10a)^-1.Third,wind resources were the most abundant from 1970 to 1979;The annual and seasonal(excepted winter)average wind speed changed abruptly in 1993,abrupt changes in the average wind speed was most pronounced in the eastern and middle sections from 1990 to 1999;The circle of the average wind speed was 22a in the entire study area and its sections.forth,average wind speed showed a decreasing trend from west to east in the research area.Lastly,wind direction of maximum wind speed was dominated by southwest wind and it was dominated by southeast wind at the eastern segment.