晚清渭河沿线地区旱涝灾害的时空特征

The Temporal and Spatial Characteristics of Drought and Flood Disasters along the Weihe River during the Late Period of Qing Dynasty

晚清时期是中国历史上自然灾害的高发期之一。通过小波分析、突变检验等方法复原晚清渭河沿线地区旱涝的时空变化状况,发现该区域旱涝灾害具有明显的阶段性、空间差异性、周期性,且存在突变。从时间上看,1844—1880年为中度、重度旱灾多发期,1880—1911年为中度、重度涝灾多发期,且短期内旱涝交替频繁。从空间上看,渭河上游沿线属于易旱地区,中下游大部分区域为易涝地区,旱涝趋势呈现出明显的东西差异。渭河沿线地区夏秋两季易发生连涝,春夏秋三季易发生连旱,季节性的旱涝对传统农业社会造成较大威胁。整体上,旱涝灾害以17到18年的周期最为突出,呈现中小周期变化特点,而在1883年、1890年及1898年存在明显的突变。晚清渭河沿线地区旱涝灾害的时空变化特征可能与ENSO、太阳活动等因素有关。

The late period of Qing Dynasty was one of the high-incidence periods of natural disasters in Chinese history,and frequent droughts and floods affected regional economic and social development.This study uses wavelet analysis,catastrophe test,and other methods to reconstruct the spatial and temporal changes of drought/flood along the mainstream of the Weihe River in the late period of Qing Dynasty.It also finds that the drought/flood disasters in this area had obvious stages,spatial differences,periodicity and mutagenicity.It was a moderate and severe droughts period in 1844-1880.But it was a moderate and severe floods period in1880-1911.Besides,another character should be noticed that droughts and floods alternated frequently in the later period.As spatial characters,it was prone to drought region along the upper reaches of the mainstream of the Weihe River,but it was prone to flooding region along the middle and lower reaches.It presented the discrepancy between the eastern region and western region.The study area was prone to continuous flood disasters in summer and autumn,and continuous drought in spring,summer,and autumn.Seasonal droughts and floods have a major impact on traditional agricultural societies.On the whole,it was about 17-18 years as a cycle of drought/flood disasters that was the most prominent,showing the characteristics of small and medium cycle changes.But there were obvious mutations in 1883,1890 and 1898.This study explores the influential factors of the characteristics of drought/flood variation and speculates that the temporal and spatial characteristics of drought and flood might be related to factors such as ENSO and solar activity.