基于小波变换的陕西夏季降水量变化特征研究

 利用陕西省18个站1959—2004年的逐月降水量资料和小波变换方法，对陕西46 a来的降水量的气候特征及夏季降水量变化特征进行了研究，并对未来夏季降水量变化趋势进行了估计。结果表明：①陕西三个不同气候带的夏季降水量主要集中在7—9月，陕北、关中和陕南7—9月的降水量值分别占全年总量的60.9％、51.2％和51.5％。②三个气候带中，关中和陕南的夏季降水量变化特征较为接近，都有12 a、6 a和2 a左右的主要时间尺度；陕北高原则明显的不同，主要是21.1 a和2.3 a的时间尺度。③根据三个地区夏季降水量变化的主要时间尺度，估计关中地区近期的夏季降水量可能偏多，陕南大致处于正常时期，陕北则是总体偏少的趋势。

Summer Rainfall Variation Characteristics over Shaanxi Province based on Wavelet Transform

Based on the monthly rainfall data of the 19 stations in Shaanxi province from 1959 to 2004 and by the wavelet transform method, the climate characteristics and the variations of summer rainfall during the previous 46 years in Shaanxi province has been investigated, and meanwhile, the change trend is estimated. The results show that: ①the summer rainfall of the three different climate belts is all concentrated in July, August and September, and the total precipitation is 60.9%, 51.2% and 51.5% of the annual precipitation in the northern Shaanxi, Guanzhong and southern Shaanxi province, respectively. ② In the three different climate belts, the characteristics of summer rainfall variation are similar in Guanzhong and in the southern Shaanxi, both have the significant time-scale change of the 12-year, 6-year and 2-year. But it is different in the northern Shaanxi plateau, in which the significant time-scale is 21.1-year and 2.3-year. ③ According to the significant time-scale of the summer rainfall, it can be estimated that the summer precipitation in the near future will be more in Guangzhong, normal in southern Shaanxi and less in northern Shaanxi.