青海省近50年极端降水事件时空分布特征

Temporal and spatial distribution of extreme precipitation events in Qinghai Province in recent 50 years

基于线性倾向估计、小波分析、Mann-Kendall检验及空间插值等方法,对1962—2013年28个均匀分布在青海省内的气象站点数据近50 a(1962—2013年)极端降水事件的时空特征进行了分析。结果表明,在长期趋势上青海省极端降水事件呈上升趋势,其强度与频数变化分别具有28 a和15 a±的主周期,并且少数站点在20世纪90年代发生突变;青海省内的极端降水事件在空间上存在明显差异,整体呈自西向东逐渐增强的特征,极端降水事件在南部地区发生频率总体高于北部地区,东南部发生极端降水的频率最高;近50 a青海省内大部分地区极端降水事件的强度与频数均呈上升趋势,其中东北部地区极端降水事件的强度上升趋势较为明显,仅有东南端与西北端呈现下降趋势,极端降水事件频数的上升趋势由东南端及西北端分别向中部加强。

Based on linear inclination estimation,wavelet analysis,Mann-Kendall test and spatial interpolation,the temporal and spatial distribution characteristics of extreme precipitation events in the past 50 years（1962—2013） of 28 meteorological stations with uniform distribution in Qinghai Province were analyzed. The results indicated that the extreme precipitation events in Qinghai Province show an increasing trend in the long-term,and their intensity and frequency variation cycles are 28 and 15 years respectively,however,a few sites show sharp changes in the 1990 s. There are obvious variations in the extreme precipitation events over Qinghai Province,which are gradually enhanced from west to east. The frequency of extreme precipitation events in the southern area is higher than that in the northern region,and the extreme precipitation in the southeastern region is the highest. In the past 50 years,the intensity and frequency of extreme precipitation events increased in most areas of Qinghai Province. The increasing trend of extreme precipitation events in the northeastern region is obvious,and only the southeastern end and the northwest end show a decreasing trend,the increasing trend of extreme precipitation e-vents is strengthened from the southeast end and the northwest end to the central part.