河北省地区50年来降水变化特征分析

利用河北省地区石家庄、张家口、承德、保定以及北京和天津6个典型气象站点1960年-2009年共50年的降水资料,运用Mann-Kendall秩相关检验法和Morlet小波变换等方法,分析了该地区近50年来降水变化特征。研究结果表明:①整体上河北省多年平均年降水在500mm以上(张家口站除外),降水集中在夏季,约占全年68%;②降水量的年际变化呈一定的减少趋势,但趋势性不明显,其中平原地区年降水量变化率相对较大;③从较大尺度来看,河北省平原区降水量存在约10年左右的周期,而山区存在15年左右的周期,且在未来的一段时间内,降水仍旧偏少;④河北省北部地区年降水量在20世纪70年代中后期和90年代中后期各发生过一次突变。

Variations of Precipitation in Recent 50 Years in Hebei Province

Based on the precipitation data of six typical meteorological stations in Hebei Province including the Shijiazhuang,Zhangjiakou,Chengde,Baoding,Beijing,and Tianjin stations from1960 to 2009,the variations of precipitation in recent 50 years in Hebei province are analyzed using the methods of Mann-kendall test and Morlet wavelet transform.The results show that(1) The average annual precipitation is above 500 mm except that in the Zhangjiakou station.Precipitation occurs mainly in summer,which accounts for about 68% of the annual precipitation;(2) The inter-annual variation of the precipitation shows a slight decreasing trend.The trend is relatively more obvious in the plain areas;(3) From the aspect of a large scale,the precipitation in the Hebei plain areas has a 10-year cycle whereas the precipitation in the mountain areas has a 15-year cycle.The precipitation is still low in the near future;and(4) There are two abrupt changes of the annual precipitation in the late 1970s and late 1990s in Hebei Province.