摘要
通过对榆林地区文献资料的搜集整理,运用统计方法和小波变换,研究了该地区明代旱灾的等级、频次、周期和气候特征。结果表明,榆林地区明代共发生旱灾70年次,平均0.25次/a,且以大旱灾为主,夏季是旱灾多发季节。旱灾的发生具有明显的阶段性,1375-1424年、1555-1584年、1590-1614年是3个旱灾少发阶段,1480-1504年、1520-1539年、1625-1644年是3个旱灾多发阶段。榆林地区明代旱灾的准周期是3 a,8 a,17 a,39 a。各等级旱灾准周期相近,短周期约为3～4a,大旱灾的第一主周期为39 a。提出了榆林地区明代存在6个干旱气候事件,干旱气候事件期间,该区由半干旱气候变为干旱气候;大旱灾发生年的年降水量为320 mm左右,中度旱灾年的年降水量380 mm左右。
Based on literature collection and sorting, and the methods of statistical analysis and wavelet transform, this paper analyzed the grades, frequency and periodicity of the drought disasters and characteristics of the climate in Yulin region during the Ming Dynasty. Results indicate that, droughts had occurred 70 times in this region during Ming Dynasty （0.25times/year on average）, and most are severe droughts. The drought-prone season in this region is Summer, and drought occurred with evident stages. The years of 1375 - 1424, 1555 - 1584 and 1590 -1614 are seldom-occurrence stages, and the years of 1480 - 1504, 1520 - 1539 and 1625 - 1644 are frequent-occurrence stages. In different time scales, the periods of drought disaster occurrences are 3 a, 8 a, 17 a and 39 a respectively. Various grades of droughts have similar quasi-periods with short quasi-period of 3 - 4a and the dominant fundamental period of severe droughts of 39 a. This paper concluded that, in Yulin region in the Ming Dynasty, there were six drought climate events, and during the events, semi-arid climate turned into arid climate. This paper estimates that, annual precipitation is about 320 mm in severe drought years, and about 380mm inmoderate drought years in Yulin region in Ming Dynasty.
出处
《自然灾害学报》
CSCD
北大核心
2013年第3期104-111,共8页
Journal of Natural Disasters
基金
国家社会科学基金重大项目(11&ZD097)
关键词
旱灾
等级
气候
小波分析
榆林地区
明代
drought
grade
Climate
wavelet analysis
Yulin region
Ming Dynasty
