1961—2009年新疆极端降水事件时空差异特征

 选用1961—2009年新疆61个测站的逐日降水资料，根据百分位值方法定义不同台站的极端降水阈值，用一元线性回归、M-K突变检验及EOF分析等方法分析各区域50年来极端降水的时空分布特征及变化趋势。结果表明：（1） 过去50年新疆极端降水事件总体表现出了波动上升的趋势，但各区域的极端降水量相差悬殊，极端降水量受地形因素影响大；（2） 阿尔泰山区、准噶尔盆地和天山山区的极端降水量分别在1986年、1983年和1989年发生显著的上升突变；（3） 极端降水阈值、年均降水量、年均极端降水量、年均极端降水频率和极端降水强度呈现山区高、盆地低的特点；年降水量越少的区域，极端降水对年降水量的贡献越大。

Spatial and Temporal Differences of Extreme Precipitation during 1961-2009 in Xinjiang,China

In this study, we analyzed the temporal and spatial distribution characteristics and variation tendency of extreme precipitation from 1961 to 2009 with daily precipitation data from 61 stations of Xinjiang, China. Considering geomorphic and climatic heterogeneity, we divided Xinjiang into six sub-regions, and applied percentile method to define the threshold of extreme precipitation events, then used linear regression, M-K test and EOF method to analyze the spatial and temporal heterogeneity. The results indicated that: (1) Over the past 50 years, there was an upward trend for the extreme precipitation in the whole region. However, the spatial and temporal heterogeneity was significant. We also found the extreme precipitation was highly related with elevation. (2) There was a significant upward mutation in the sub-regions of Altay Mountains, the Junggar Basin and the Tianshan Mountains in 1986, 1983 and 1989, respectively. (3) Annual precipitation, extreme precipitation, annual extreme precipitation frequency and intensity of extreme precipitation showed a characteristic of high in mountainous area, low in plain area. The extreme precipitation contributed more to annual precipitation when annual precipitation is lower.