山西省明清时期雹灾时空分布特征分析

Analysis of Spatial and Temporal Distribution of Hail Disasters in Shanxi during Ming and Qing Dynasty

通过收集明清时期（1372-1911年）山西省历史文献资料,整理并分析该地区的雹灾频次、等级,探索了其时间分布特征与空间分布特征。明清时期山西省共发生雹灾707次,其中轻度雹灾246次,中度雹灾250次,重度雹灾211次。从时间分布来看,山西省雹灾有明显的阶段性特点,总体呈前期较少,而中后期相对较多且后期尤为突出的特点;其季节变化明显,雹灾集中分布于夏季,秋季次之,冬春季最少,且夏秋两季雹灾发生频次占89%。小波分析表明：明清时期山西省雹灾分布具有明显的周期性,主要表现为2年、6~7年、10年、22~24年以及70年的周期,其中第1主周期70年与降水量周期一致。采用交叉小波分析法对山西省年雹灾发生次数和降水量情况进行分析,发现两者在不同时间尺度上具有不同程度的相关关系。从空间分布来看,明清时期山西省的雹灾频次分布与强度分布在空间上有一定的一致性,高原及高山地区较低地更易发生雹灾。

We arrange and analyze the frequencies and grades of hail disasters to explore the spatial and temporal distribution of hail disasters in Shanxi from 1372 to 1911 through the collection of historic literacy of Shanxi.There were 707 hail disasters in this province from 1372 to 1911,among them,mid,moderate and serious ones are246,250 and 211 respectively. From the temporal distribution,the hail disaster in Shanxi has obvious stage characteristics,with a general upward trend,less in the early stage,more in the middle and later,especially severe in the late stage; its seasonal change is obvious,disasters are more concentrated in summer,less in autumn,least in winter and spring,and the total occurrence frequency accounts for 89% in summer and autumn. Wavelet transform result shows： the distribution of hail disasters in Shanxi from 1372 to 1911 has significant periodicity,the disasters have three periods of 2a,6 to 7a,10 a,22 to 24 a and 70 a,among them the first main period 70 a is in consistent with the precipitation period. Using cross wavelet method to analyze the relation between the precipitation and annual numbers of hail disasters in Shanxi Province,it is found that the relation between precipitation and annual numbers of hail disasters has different degree of correlation on different time scales. Seeing from the spatial distribution,there is a certain degree of consistency of the frequency distribution and intensity distribution of hail disasters in Shanxi during Ming and Qing Dynasty,plateau and mountain area were highly prone to hail disasters than lowland.