清代华中地区干旱灾害时间特征及成因分析

Analysis of temporal characteristics and causes of drought disaster in Central China during Qing dynasty

基于清代(1644-1911年)华中地区干旱灾害历史资料的搜集与整理,利用启发式分割算法和互补集合经验模态函数等方法,分析华中地区干旱灾害的时间分布特征。结果表明:1)清代华中地区旱灾发生频繁,共208年次,占总年数的77.6%,其变化总体上呈下降趋势。2)华中地区旱灾于1694年发生突变,突变后旱灾频率明显减少。3)华中地区旱灾存在显著的周期性,存在2.6a、9.7a、21.6a、29.4a和102.1a的周期,其中9.7a和21.6a的周期与太阳黑子周期相一致。4)交叉小波分析表明太阳黑子数与华中地区旱灾变化在不同时间段内具有不同程度的相关关系。

Based on the collation of historical data about drought disaster during the Qing dynasty from 1644 to1911 in Central China,we analyzed the temporal distribution of drought disasters in central China by heuristic segmentation algorithm and complete ensemble empirical mode decomposition. The results show：（1）The drought disaster occurred frequently in Central China during the Qing dynasty,which took 208 years,accounting for 77.6% of the whole Qing dynasty. The overall trend was slight decrease.（2）The drought disaster mutated in 1694.The frequency of drought decreased significantly after the mutation.（3）Drought disaster had significant periods of2. 6a,9. 7a,21. 6a,29. 4a and 102. 1a. The periods of 9. 7a and 21. 6a were consistent with the sunspot periods.（4）Cross-wavelet analysis shows that sunspot number and drought disaster level sequence had different degree of relation in different time periods.