重庆市110年来冰雹灾害的时空分布特征

Temporal and Spatial Distribution Characteristics of Hail Disasters in the Past 110 Years in Chongqing

利用重庆市1901—2010年有关冰雹资料,对重庆市110年来冰雹灾害的时空分布特征进行系统分析和研究。结果表明,重庆市冰雹灾害的时空分布均体现出不均衡的特点;以10年为周期对1901—2010年全部冰雹灾害进行分析还发现,重庆市在上世纪前40年冰雹灾害较少,以后每个年代均大幅度增加,直到70年代达到最高,之后近30多年来重庆市年降雹日数有所减少;重庆市除1月份外其余月份均可能有冰雹灾害;降雹主要集中在3月～8月,4月发生日数最多;冰雹主要发生在14时至次日凌晨2时这个时段;空间分布方面呈现"东多西少"的特点,同时渝东北比渝东南发生冰雹灾害的机率大。研究认为,重庆市110年来冰雹灾害的空间分布特征与地形起伏和冷空气前行路径有关。

On the base of related hail data in Chongqing from 1901 to 2010, this paper analyses and researches in detail the hail＇s spatial-temporal distribution characteristic. The results indicate that the hail disasters of Chongqing have an uneven distribution characteristic on spatial and temporal. The hail occurrence has obvious yearly, monthly and daily variation. There were less hail dis- asters in early 40 years of last century. After that it increased significantly in each age till 1970＇s. The hail＇s number is highest in 1975. But in recent 30 years, the yearly hail number of Chongqing has decreased. Except January, there has possibility of hail disas- ter in Chongqing. But the hail disaster mainly concentrated from March to August. And April has highest hail number. The hail disaster occurs mainly from 14 to 2 o＇clock in the next morning. At spatial distribution, the eastern part of Chongqing had more hails than the western part. The northeastern part had more chances of hail disaster than southeastern. The reasons of this spatial distribution are landform and cold air moving path.