过去2000年来陕西地区冰雹灾害及其对农业的影响研究

Research on Hail Disasters and Its Effects on Agricultural in Shaanxi Region for the Past 2000 Years

通过对过去2000年陕西地区冰雹灾害资料的搜集与整理,利用Arc GIS、Matlab等软件,从不同阶段、不同季节和不同影响程度等方面统计分析了冰雹灾害的时空变化特征,并探讨了冰雹灾害对区域农业生产的影响。结果表明:公元0—2014年以来陕西地区共发生1296次冰雹灾害事件,平均每1.55年发生1次,在冰雹灾害发生的等级中初等雹灾、中等雹灾和特等雹灾各发生315次、867次和114次,分别占雹灾发生次数的24.3%、66.9%和8.8%,以中等雹灾为主;依据器测观测工具的转变和发展,将历史时期陕西地区冰雹灾害在时间尺度上划分为3个阶段,即公元0—1911年、1912—1980年和1981—2014年期间冰雹灾害分别发生了375次、418次和503次,整体上呈现前期少、后期多的年代际变化特点;陕西地区的冰雹灾害具有明显的季节变化特征,且年内变化具有显著的月份差异,各阶段在季节和月份上的变化特征与过去2000年以来冰雹灾害发生规律相对应;冰雹灾害在时间尺度上存在着11年和16年左右2个振荡周期,与太阳活动周期密切相关;冰雹灾害在空间分布上存在明显的差异性,具有北多南少的空间变化特征;不同季节、不同影响程度下,冰雹灾害对陕西地区农业生产的影响不同,集中分布在关中平原及其以北地区。20世纪以来,区域人类活动方式及活动强度发生了变化,区内人口、社会经济及农业生产的集中化加剧了局部地区农业的受灾程度。

By collecting and sorting the hail disasters of historical literature in Shaanxi region for the past 2000 years,and analyzing the spatial and temporal distribution characteristics of hail disasters and discusses its effects on regional agricultural by Arc GIS and Matlab software from different stages,seasons,influence degree,and so on. The results showed that there have occurred 1296 times of hail disasters in Shaanxi region during 0 to 2014 AD,approximately once every 1. 55 years in average,hail disasters are given priority to with medium hailstorm,including elementary,secondary and special hailstorms occurred 315 times,867 times and 867 times each other,respectively accounted for 24. 3%,66. 9% and 24. 3% of hail disasters in total. According to the change and development of instrumental observation instrument,hail disasters are divided into 3 stages on the times scale,including the year 0 to year 1911,the year 1912 to 1980 and the year 1980 to 2014,during the period when hail disasters respectively accounted for 375 times,418 times and 503 times in Shaanxi region,on the whole,showing the decadal changes characteristic of hail disasters that less in early and much later in historical period of Shaanxi,hail disasters have obvious seasonal variation characteristics and present prominently monthly difference which within the year,and in each stage,characteristics of hail disasters in the seasonal and monthly are related to the occurrence with past 2000 years of Shaanxi. Hail disaster exists in 11 years and 16 years two period of oscillation on time scale,which has relationship with sunspot activity cycle. There are obvious different in the spatial distribution of hail disaster where the characteristics of the northern are more than the southern. With the influence of different seasons and different degrees,the effects of hail disasters on agricultural production in Shanxi Province are different,the distributions are mainly in the Guanzhong plain and north of the region. Since the 20 th century,regional human activity way and strength has changed,the centralization of the population,social economy and agricultural production in the area increased agricultural level of disasters of local areas.