陕西地区1368-2013年冰雹灾害时空分布特征研究

Analysis of hail disasters and its spatial and temporal distribution characteristics in Shaanxi region from 1368 to 2013

通过对陕西地区1368-2013a间冰雹灾害事件的搜集整理,利用Arc GIS及Matlab等软件统计分析了该地区冰雹灾害的时空分布特征及周期变化规律。结果表明:1368-2013a间,陕西地区共发生了991次冰雹灾害事件,平均每年发生1.54次,其中初等雹灾、中等雹灾和特等雹灾分别占冰雹灾害的25.43%、61.96%和12.61%。冰雹灾害在时间尺度上存在着175a、250a和500a等3个振荡周期。在时间分布上,冰雹灾害发生的频率呈现出波浪式的上升趋势,18世纪以后,冰雹灾害的发生频次明显增加,且夏秋连雹的现象最多。在空间分布上,区域内雹灾存在明显空间的差异,冰雹灾害主要发生在关中平原西部及以北地区,存在以榆林、延安及陇县为中心的高频区域。

Hail disasters events between 1368 -2013 in Shaanxi province were collected to statistically analyze the characteristics of spatial and temporal distribution and cycle change discipline of hail disasters by using ArcGIS and Matlab software. The results showed that 991 times of hail disasters occurred in Shaanxi region during 1368-2013a, about 1.54 times occurred each year, including elementary, secondary and special hailstorms that accounted for 25.43%, 61.96% and 12.61% of total hail disasters,respectively. Hail disasters existed three periods of oscillation on time scale by 175a, 250 a and 500a. Hail disasters occurring frequency presented a wave of rising trend in time distribution, obviously increased after the 18th century; it mainly concentrated in summer and autumn. On the spatial distribution, hail disasters also existed obvious difference, mainly occurred in the western of Guanzhong plain and north region. There had three high frequency centers in Yulin, Yanan and Longxian area.