近53a宁夏暴雨时空分布特征

Temporal and Spatial Distribution Characteristics of Rainstorms in Ningxia During 1961- 2013

利用1961~2013年宁夏25个常规观测站资料和2007~2013年220个区域自动站暴雨观测资料，对宁夏暴雨的气候特征进行分析，发现宁夏暴雨呈“南多北少”的整体分布特征，暴雨易发区为中卫市以南和贺兰山东麓。近53 a来，宁夏暴雨有3个集中期，尤其是21世纪后暴雨剧增，其中宁夏南部山区和银川平原暴雨频数增加明显。宁夏暴雨存在明显的月、日变化特征，暴雨主要发生在7月上旬到9月上旬，短时暴雨主要集中在午后到夜间（即下午16时至次日02时），这一特征与气温（热量）及对流发展的日变化比较一致。宁夏暴雨发生频数存在明显的准16 a、20 a年代际、2~3 a年际变化特征和准10 d的低频振荡特征。

Based on the daily precipitation data of 25 conventional weather stations from 1961 to 2013 and 220 automatic weather sta-tions from 2007 to 2013 in Ningxia,the temporal and spatial distribution characteristics of rainstorms in Ningxia were analyzed. The re-sults showed that the rainstorms in Ningxia had been more in the southern part and less in the northern part as a whole,and concentrat-ed in the south of Zhongwei and east of the Helan Mountain. In the past 53 years,there were three concentration periods of rainstorm including 1961-1979,1995-2002 and 2006-2013,especially the rainstorms increased sharply after 2000,which mainly appeared in southern mountains of Ningxia and Yinchuan plain. The daily and monthly changes of rainstorm in Ningxia were obvious. The rain-storms concentrated from July to September,and the short-time rainstorms mainly occurred from 16：00 to 02：00,which was more consistent with the daily variation of temperature. The rainstorms in Ningxia had obvious 16 a and 20 a interdecadal,2-3 a interannu-al period oscillation and 10 d low frequency oscillation characteristics analyzed by using Mexico-hat wavelet.