川西南山地冰雹灾害的时空特征

Spatial-temporal Characteristics of Hail Disasters in the Southwest Mountain Region of Sichuan

利用川西南山地19个地面气象观测站1978-2014年的逐日观测资料,分析冰雹天气的时空分布特征。结果表明：川西南山地的冰雹日数空间分布差异较大,东北部与西北部冰雹日数最多,南部次之,中部最少;冰雹日数与海拔高度显著正相关;近37 a川西南山地冰雹日数总体呈减少趋势,冕宁减少趋势最为明显;冰雹日数春季最多,夏季次之,冬季最少;地理位置靠近和海拔高度相近的站点,降雹频率的月际变化特征相似。

Based on hail data from 19 meteorological stations in the southwest mountain region of Sichuan during 1978- 2014,the spatial and temporal characteristics of hail days were studied. The results displayed that the spatial distribution of hail days was obviously different during 1978- 2014 in the southwest mountain region of Sichuan,hail days occurred most in the northwest and northeast,less in the south and least in the middle area. The correlation between hail days and altitude was significantly positive. In the past 37 years,the annual hail days had decreasing trend,and decrease trend was the most significant in Mianning. The hail days were most in spring and least in winter. The accumulative hail days were most in April with 117 days during 1978- 2014. There were similar inter- monthly variation for hail days in stations with neighbouring geographical position and similar altitudes.