摘要
通过对明代固原地区历史资料的搜集、整理、分析,对其干旱灾害等级化及成因等问题进行了研究。结果表明,固原地区自1368年到1644年间的277a中,共发生干旱灾害118次,平均每2.35a发生1次;其中轻度旱灾20次,占旱灾总数的16.9%;中度旱灾38次,占旱灾总数的32.3%;大旱灾42次,占旱灾总数的35.6%;特大旱灾18次,占旱灾总数的15.2%。该地区旱灾可分为4个阶段:第1阶段的1368—1424年和第3阶段的1505—1604年是旱灾的低发期;第2阶段的1425—1504年和第4阶段的1605—1644年是旱灾的高发期。该地区旱灾的季节性特征是单季旱占55.9%,其中夏旱所占比重最高,春旱、秋旱次之,冬旱较为稀少;季节性连旱占44.1%,其中春夏连旱和春夏秋3季连旱分别高达17.8%、15.3%。该地区明代处于气候的干冷期,年降水量减少是发生旱灾的主要原因。固原地区具有指示该时代气候变化特征的5次干旱气候事件,分别是明代的1437—1442年、1481—1490年、1608—1617年、1627—1634年、1637—1641年。
Based on statistics of the drought events recorded in historical documents,the temporal distribution,degree and causes of drought disasters in Guyuan region of Ningxia Province in the Ming Dynasty(1368-1644) were analyzed in this paper.Results showed that 118 drought disasters,or once every 2.35 years,occurred in Guyuan in the Ming Dynasty.In this region,the slight drought accounted for 16.9% of the total droughts,the moderate drought accounted for 32.3%,the severe drought accounted for 35.6%,and the very severe drought accounted for 15.2%.Occurrence of drought disasters in Guyuan in the Ming Dynasty can be divided into four main periods: the first phase of 1368-1424 and the third phase of 1505-1604,when the frequencies of drought disaster were relatively low;the second phase of 1425-1504 and the forth phase of 1605-1644,when the frequencies of drought disaster were relatively high.The drought disasters had obvious seasonal difference and the single-season drought frequency was 55.9%.Drought disasters occurred in summer was the most,that in spring and autumn second,and that in winter the least.The continuously seasonal drought frequency was 44.1%,of which the spring-summer continuous drought disasters were up to 17.8%,and the spring-summer-autumn continuous drought disasters were up to 15.3%.Climate was much drier and colder in the Ming Dynasty in this region,and annual precipitation reduction was the main reason for the drought.We determined 5 draught events in Guyuan region in the Ming Dynasty,which indicated the five periods of climate changes in Guyuan region in 1437-1442,1481-1490,1608-1617,1627-1634,and 1637-1641.
出处
《中国沙漠》
CSCD
北大核心
2012年第2期525-530,共6页
Journal of Desert Research
基金
教育部人文社会科学重大招标项目(05JJD770014)
中国科学院黄土与第四纪地质国家重点实验室项目(SKLLQG0605)资助
关键词
干旱灾害
灾害等级
旱灾成因
干旱气候事件
固原地区
drought disaster
disaster grade
reasons of drought
drought events
Guyuan region of Ningxia Province
