Abstract:

Based on the meteorological data from eight observation stations in the Aletai region from 1954 to 2010，the characteristic of hail disasters was analyzed by using mathematical statistics method and Mann － Kendall test． Results show that the interannual variation of hail had a 3 － 5 years oscillation cycle and presented decreasing trend on the whole． After the year of 1996，the hail frequency decreased significantly，which might be related to the abrupt change of climate． The seasonal variation of hail disasters was obvious with high frequency in summer and little occurrence in winter． The hail duration generally remained about 10 min，and the duration less than 5 min，10 min accounted for 61． 2% and 89． 3%，respectively，while the duration more than 30 min accounted only for 1． 5%．The hail occurred more in Jimunai，Aletai，Qinghe and less in other counties，and little in Fuhai． The occurrence of hail was closely related to topography and altitude，with the increasing of altitude，the hail times presented logarithmic increasing trend． The gradient of the west of Aletai，Buerjin towards to Jimunai was the largest，and there was high risk in the north and east region of Altai Mountains，while less risk in the central and southern area．

Key words: Xinjiang Aletai, hail, climate characteristic, risk zoning

摘要：

利用阿勒泰地区8个观测站1954～2010年气候观测资料，应用数理统计方法，分析近57 a的冰雹灾害气候特征，用Mann－Kendall法判断冰雹气候突变得出以下结论:年际变化存在3～5 a震荡周期，总体呈递减趋势;1996年后，冰雹灾害发生频率显著降低，初步分析与气候突变有关。冰雹的季节变化特征显著，夏季频次高，秋季次之，冬季最少。冰雹灾害持续时间一般维持在10 min左右，其中持续时间＜5 min的占总次数61．2%，持续时间＜10min的占89．3%，持续时间＞30 min占1．5%落区分布规律:吉木乃阿勒泰青河居多，其他县市较少，福海最少。冰雹与地形、海拔高度关系密切，随海拔高度升高，冰雹日数呈对数关系增长。依据信息扩散理论方法，对冰雹危险性区划显示，阿勒泰地区西部沿布尔津—吉木乃一线梯度最大，北部、东部沿山一带危险性大，中部、南部的两河流域风险较小。

关键词:
新疆阿勒泰, 冰雹, 气候特征, 危险性区划