近200年来关中地区干旱灾害时空变化研究

通过对历史文献资料的收集、统计和分析,对1800-2000年关中地区干旱灾害的等级序列、时间变化、空间变化和干旱变化趋势拟合进行了研究。结果表明:关中地区近200年共发生干旱灾害94次,平均2.14年发生一次;干旱灾害的等级序列可分为四级,其中发生轻旱灾24次,占旱灾总数的26.6%;中等旱灾47次,占旱灾总数的48.9%;大旱灾19次,占旱灾总数的20.2%;特大旱灾4次,占旱灾总数的4.3%;从1900年代开始,干旱灾害发生频率有明显的增加;旱灾以夏旱和春旱最多,占发生次数的32%和28.1%;关中地区中部和东部为旱灾的高发区,其中渭南地区干旱的发生次数远远高于其他地区;从19世纪至20世纪40年代,拟合曲线有增加趋势;40年代至今旱灾略有下降。

Spacial-temporal Changes of Drought Disaster in Guanzhong Area in Recent 200 Years

According to the historical materials of Guanzhong region during A.D 1890-2000,the drought disaster rank,the time variation,spacial variation and the arid change tendency fitting were studied in this paper.The results showed that drought disasters accurred 94 times and averagely occurred one time per 2.14 year.The grade sequence of drought disaster was divided into four classes.Light drought disasters were 24 times,accounted for 26.6% of drought total amount;The moderate drought accounted for 48.9%;The big drought accounted for 20.2%;The heavest drought disasters were 4 times,accounted for 4.3%.The drought disaster in Guanzhong area were remarkablly increaced from 1900s.The drought occurred in summer and in spring were the most,accounting for 32% and 28.1% of tatal disasters.The drought mainly accurred in middle and west area of Guanzhong,among them Weinan suffered the disaster more than other areas.From the 19th century to the 1940s of the 20th century,the drougth disasters increased little more.