甘肃省近50年降水量及气候变化趋势研究

Variation Trend of Precipitation and Climate Factors in Gansu Province for the Last 50 years

应用线性倾向估算法、累积距平以及Mann-Kendall法对甘肃省1957-2006年以来的降水量、温度、风速、日照百分率的变化趋势和突变进行了分析。结果表明:总体而言甘肃省近50年来的平均降水量存在减少趋势,但河西中部、西部地区的降水量表现出增加的趋势;从四季降水量变化来看,除冬季降水量增加外,其余季节降水量均出现不同程度的减小,秋季减小趋势更为明显;降水量趋势突变发生在20世纪90年代。甘肃省近50年来的平均气温表现出增加趋势,其倾向率为0.21℃/10a,在1996年发生突变;风速为减小趋势,突变发生时间为1985年;日照百分率也表现出增加趋势,其倾向率为0.17%/10a。

Based on the observational data of 31 meteorological stations in Gansu Province from 1957 to 2006, the spatial and temporal distributions and their trends of precipitation and climate factors were investigated by using linear regression methodology method and Mann - Kendall method. The result showed that the annual total precipitation displayed steadily decrease in the last 50 years, but in some part of Gansu Province the annual rainfall had an increasing tendency. The seasonal analyses indicated that the decrease of precipitation occurred mainly in spring, summer and autumn. The annual average temperature from 1957 to 2006 displayed increasing, the tendency rate was 0. 21℃/10a, and the annual sunshine percentage had the same tendency. The wind speed showed decreased tendency form 1957 to 2006, the tendency rate was -0.08m ·s^-1/10a, sudden change took place in 1985.