摘要
根据延安地区历史时期旱灾资料,研究了该地区明清旱灾差异和气候的不同。结果表明,延安地区明代(1368-1643年)276年内,共发生旱灾115次,平均每2.4年发生1次;其中轻度旱灾17次,中度旱灾52次,大旱灾34次,特大旱灾12次。清代(1644-1912年)的269年里,共发生旱灾35次,平均7.7年发生1次;其中轻度旱灾6次,中度旱灾25次,大旱灾3次,特大旱灾1次。延安地区明清旱灾差异显著,明代旱灾频次是清代的3.2倍;明代旱灾等级比清代高,前者大旱灾与特大旱灾占旱灾总数的40%,后者的仅占11.6%。明代干旱气候事件频繁,清代干旱气候事件少见。延安地区明代旱灾发生频繁和等级高的原因是当时气候变干和干旱气候事件频繁出现引起的,说明明代是气候较为干旱的时期。延安地区清代旱灾频次低和等级低是当时降水量较多的结果,说明清代是较湿润的时期。明代和清代大旱灾发生时的年均降水量为440mm左右,特大旱灾发生时的年均降水量为360mm左右。
According to historical documents of draught disaster in Yan＇ an, the authors studied the draught and the climate difference between Ming and Qing Dynasty in Yan＇ an. As the results showed, there were 115 drought dis- asters in Yan＇ an in Ming Dynasty, and the disasters occurred once every2.4 years. In this period, the numbers of the slight, moderate, serious and extremely serious drought disasters respectively were 17,52, 34, 12. There were 35 drought disasters in Yan＇ an in Qing Dynasty, and the disasters occurred once every 7.7 years. In this period, the numbers of the slight, moderate, serious and extremely serious drought disasters respectively were 6, 25, 3, 1. The draught difference between Ming and Qing Dynasty in Yan＇ an was distinct. The number of draught in Ming Dynasty is 3.2 times of that in Qing Dynasty. The grades of draught disaster in Ming Dynasty are obviously higher than that in Qing Dynasty. The former＇ s serious and extremely serious drought disasters were 40 percent of the total draught numbers, and the latter＇ s were only 11.6 percent. Ming＇ s draught climate events occurred frequently, and Qing＇ s were scarce. The reasons of Ming＇ s frequent draught disasters and higher draught grades were that the climate became drier and the draught climate events occurred frequently, which indicated that Ming Dynasty was adry period. The reasons of Qing＇ s fewer draught disasters and lower draught grades were that there were much more precipitation in this period, which indicated that Qing Dynasty was a relatively wet period. When the serious drought disasters occurred in Ming and Qing Dynasty in Yam＇ an, the annual precipitation was about 440mm. When the extremely serious drought disasters occurred, the annual precipitation was about 360mm.
出处
《自然灾害学报》
CSCD
北大核心
2011年第5期82-89,共8页
Journal of Natural Disasters
基金
陕西省灾害监测与模拟重点实验室项目(09JS074)
教育部人文社会科学研究基地重大招标项目(05JJD770014)
关键词
延安地区
旱灾差异
明代
清代
灾害等级
干旱气候事件
Yam＇ an area
draught disasters difference
Ming Dynasty
Qing Dynasty
disaster grade
draught climate event
