我国秦汉时期疫灾时空特征分析

Temporal and Spatial Characteristics of Epidemic Disasters during Qin and Han Dynasty in China

通过对各种历史文献资料的搜集、整理及统计分析,利用最小二乘法、小波分析和空间Kriging插值等方法,对秦汉时期(221BC^220AD)共441年疫灾的等级、发生频率、时空分布、成因等进行了相应的研究。结果表明,秦汉时期,共记载疫灾66次,平均6.68年发生1次。其中,疫灾以中度疫灾为主,占疫灾总数的40.9%;其次是特大疫灾和轻度疫灾,分别占疫灾总数的27.3%和22.7%;大疫灾发生的频率较低,占疫灾总数的9.1%。疫灾在8年时间尺度上显示出较强的周期性。在空间分布上,北方地区疫灾次数明显多于南方地区。疫灾发生的频率具有明显的波动性,并且随着时间的发展,在波动中有上升的趋势,东汉后期是秦汉时期疫灾发生频率最高的时期。秦汉时期发生疫灾的主要原因是气候变化,其他灾害相伴而生,战争、社会动乱等。

All kinds of historical documents involved in epidemic disasters during the Qin and Han dynasty in China were collected, reorganized and statistically analyzed, and the grade, occurrence frequency, temporal and spatial distribution, and causes of epidemic disasters in these 441 years were studied by using the methods of least squares, wavelet analysis and Kriging spatial interpolation. The results showed that： during the Qin and Han dynasty, 66 times of epidemic disasters were recorded, and the occurrence frequency was once every 6.68 years. The moderate, extremely serious, light, and serious epidemic disasters accounted for 40.9%, 27.3%, 22.7% and 9.1% of all epidemic disasters, respectively. The epidemic disasters exhibited a strong periodicity of eight years. In the spatial distribution, the times of epidemic disaster occurrence in northern area was obviously more than that in southern area. Meanwhile, the occurrence frequency of epidemic disasters was characterized by obvious fluctuation along with the development of time, and it had a rising trend in fluctuation. The late Eastem-Han dynasty had the highest occurrence frequency of epidemic disasters. The occurrence of epidemic disasters during the Qin and Han dynasty was caused mainly by climate change, other disasters, war, and social unrest.