塔克拉玛干沙漠南缘极端降水变化趋势与突变特征

利用1966-2009年塔克拉玛干沙漠南缘16个站逐日的降水资料，运用累积频率的方法确定了塔克拉玛干沙漠南缘各站极端降水量的阈值。通过Mann-Kendall法和滑动t检验方法进行比较分析，得出极端降水指数的突变特征。结果表明：塔克拉玛干沙漠南缘极端降水量、频率、强度、年最大日降水量均呈增加趋势。极端降水量和频率的突变点分别是1998、 1997年附近，极端降水频率与极端降水量呈较好的正相关。极端降水的强度和年最大日降水量的突变点分别为1985和1981、1985年。极端降水量的增加可能是由极端降水日数的增加和极端降水强度的增强共同引起的。

The Changing Tendency and Characteristics of Extreme Rainfall on the Southern Edge of Taklamakan

Based on rainfall data of 16 stations day by day on the edge of Taklimakan during 1966 to 2009, threshold levels of extreme rainfall data on each station have been confirmed on the method of cumulative frequency. According to comparative analysis between Mann-Kendall and T-test, the prominent characteristics of extreme rainfall index were got. The results show that it has an increasing tendency of extreme rainfall data, frequency, intensity, and maximum daily rainfall data in a year in the southern edge of Taklamakan. The extreme rainfall capacity and the changing point of frequency are near the year of 1998 and 1997 respectively, and there is a better positive correlation. The intensity of extreme rainfall capacity and the changing point of maximum daily rainfall data in a year are in the year of 1985and 1981 and 1985 respectively, and the increasing extreme rainfall capacity may be aroused together by the increasing extreme daily rainfall capacity and the extreme rainfall intensity.