1961-2009年新疆伊犁地区暴雨日数时空变化特征

根据1961-2009年伊犁地区10个自动站逐日降水资料，采用线性趋势、累积距平、M-K 突变检验、以及周期分析等方法，分析近 49 a暴雨日数的年代际、年际、月、旬、空间的变化规律及其周期变化，并对该地区近 49 a暴雨日数进行突变检验。结果表明：近49 a来伊犁地区的暴雨日数呈上升趋势，其线性倾向率为0.107 d/10 a；暴雨主要发生在5-7月，约占总数的73.2 %，其中6月最多，7月次之；暴雨异常偏少年为1995年，暴雨异常偏多年为1996、1999、2002、2003和2007年；暴雨日数由西向东、由北向南均呈逐渐增加趋势；暴雨日数发生频次存在显著2.8 a左右年际变化周期。

Temporal and spatial distribution of rainstorm days from 1961 to 2009 in Yili area

Based on the daily precipitation data from 10 automatic weather stations from 1961 to 2009 in Yili area,the temporal and spatial distribution of the inter-decadal,annual,monthly rainstorm days and variation of their cycles were analyzed using methods of a linear trend,a cumulative anomaly,an M-K test,and a cycle analysis.The results showed that the rainstorm days are in an increasing trend in the recent 49 years in Yili area,and its linear trend increases 0.107 days every decade.Rainstorm occurs mainly during May to July which accounts for 73.2％ of the total,especially in June,then in July.The year with the abnormal fewer rainstorm day is 1995,while the years with the abnormal more rainstorm days include 1996,1999,2002,2003 and 2007.The rainstorm days gradually increase from west to east and from north to south.There is a 2.8 years cycle for the annual rainstorm days.