明代江西地区旱灾发生频次分析

Analysis of Occurrence Frequency of Drought Disaster in Jiangxi in Ming Dynasty

通过对明代江西地区历史文献中干旱灾害记载的整理统计,分析了该时期江西地区旱灾的时间变化特征、等级和成因。结果表明,在明代276年间,江西地区共有140个年份发生过旱灾,占比为50.7%。明代江西地区旱灾主要分为2个发生阶段:1370～1500年代旱灾偏少和1510～1630年代旱灾多发期。整个明代时期,江西地区旱灾发生次数较多,频次呈较明显增加趋势,特别是中后期为旱灾发生波动变化较明显的时期。明代江西地区干旱灾害可划分为4个等级:(1)一级轻度旱灾和二级中度旱灾,各发生109次和107次,分别占旱灾总次数的44.5%和43.7%;(2)三级大旱灾发生24次,平均每11.5年发生1次,占旱灾总次数的9.8%;(3)四级特大旱灾发生次数最少,仅有5次,约占旱灾总次数的2.0%。

Through the statistics of the drought disaster events recorded in historical documents,the author analyzed the temporal variation characteristics,grades and causes of drought disasters in Jiangxi in the Ming Dynasty(1368~1643).The results showed that:during 276 years of the Ming Dynasty,a total of 140 years of drought disasters occurred in Jiangxi,accounting for 50.7%.The occurrence of drought disasters in Jiangxi in the Ming Dynasty could be divided into two main periods:in 1370~1500,the frequency of drought disaster was relatively low;in 1510~1630,the frequency of drought disaster was relatively high.From the early to the late Ming Dynasty,the occurrence frequency of drought disasters in Jiangxi revealed an obvious increasing trend,especially in the middle and later Ming Dynasty.The drought disasters in Jiangxi area in the Ming Dynasty could be divided into 4 grades:the grade-1 slight drought disaster(109 times)and the grade-2 moderate drought disaster(107 times)accounted for 44.5%and 43.7%of all drought disaster occurrence frequency,respectively;the grade-3 serious drought disaster(24 times,once every 11.5 years)accounted for 9.8%;the grade-4 heavy drought disaster(5 times)accounted for only about 2.0%.