西北地区冰雹分布特征

冰雹具有明显的区域特征，利用西北地区(陕、甘、宁、青、新)192个气象站点41年的冰雹和雷暴资料(部分站点资料不足41年)分析了冰雹的分布特征及与雷暴、海拔的关系，探讨了西北地区5省冰雹多发的原因，综合各省的冰雹分析，给出了冰雹主要的产生源地和移动路径。西北地区冰雹分布呈3个频发中心，冰雹的发生与雷暴、海拔密切正相关，相关系数分别为0．78和0．84，冰雹移动路径多为西北一东南和西一东走向，近10年来冰雹已经大为减少。综合考虑地形和其他天气因素，给出了西北地区产生冰雹的5个主要源地。

Characteristics of Hail Distribution in Northwest China

With the 40-year hail and thunderstorm data from meteorological stations over Northwest China, an analysis was made of the distribution characteristics of hails, and the relation with altitude, topography and concomitant thunderstorms. The causes of frequently occurring hails in Northwest China are discussed. The result indicates that hails in this area are concentrated mainly around three areas; the occurrence of hails is highly correlated with thunderstorms and altitude with the correlation coefficients being 0.78 and 0.84; and in the last 10 years hail disasters decreased greatly. Considering meteorological factors and topography, five source areas of hails are pointed out.