1616-1911年河南省异常洪涝灾害的时空特征及其成因

通过分类和整理1616-1911年河南省洪涝灾害记录，建立了洪涝灾害等级序列。采用Morlet小波变换、DBSCAN空间聚类等方法研究了河南异常洪涝灾害时空分异规律。探讨了洪涝发生对东亚夏季风和太阳活动变化的响应。结果表明：河南省洪涝灾害的发生存在80 a、30 a、20 a、9 a 4个主周期。在不同冷暖时期，北部地区洪涝灾害强度大于南部地区，且气候冷期洪涝强度和发生区域明显大于气候暖期，这除了与降水分布有关外，可能还与水域分布有关。河南南、北部洪涝强度对东亚夏季风强度的响应存在较大的差异，在东亚夏季风强年，季风系统位置偏北，易引起北部地区多洪涝；在东亚夏季风弱年，季风系统位置偏南，易引起南部地区多洪涝。不同时间尺度上二者相关性有显著差异，在100 a及以下时间尺度上，东亚夏季风对河南南部的洪涝影响显著；在200 a时间尺度上，东亚夏季风对河南北部的洪涝影响更显著。洪涝灾害易出现在太阳黑子数极值年及其附近，出现在极大值M年的频率高于极小值m年。河南北部的洪涝在各种不同时间尺度上对太阳黑子周期长度（SCL）的变化均有显著响应，河南南部的洪涝只在100 a尺度上对SCL的变化有显著响应，即当SCL变长（太阳活动减弱）时，有利于河南北部洪涝的少发；反之有利于洪涝的多发。河南省洪涝的变化可能是太阳活动与东亚夏季风共同作用的结果。进一步揭示历史洪涝发生规律及其成因对于正确预估未来旱涝趋势具有重要意义。

Spatial-temporal characteristics and its causes of flood disasters in Henan province from 1616 to 1911

By classifying and sorting the flood disaster records of Henan province from 1616 to 1911, the grade sequence of flood disaster is established. Moreover, the temporal and spatial difference law of the abnormal flood in Henan was studied by using the methods of Morlet wavelet transform and spatial clustering, etc., and the response of the occurring flood to the East Asian summer monsoon and the variation of the solar activity was discussed. Results show that there are four primary periods of 80 a, 30 a, 20 a and 9 a for the outbreak of flood disaster in Henan province. In the periods with different air temperature, the intensity of flood disaster in the northern areas and in the climatic cold period is greater than that in the southern areas and in the climatic warm period, which are related to the precipitation distribution and the water area distribution. The great difference of flood intensity response to East Asian summer monsoon between southern and northern Henan is obvious. In the strong (weak) East Asian summer monsoon years, the systematic position of monsoon tends to north(south), so it is easy to cause floods in the northern (southern) areas. The correlation between the two factors at different time scales has great difference. At the time scale of 100 or less than 100 years, the East Asian summer monsoon has a significant effect on the flood in southern Henan; at the 200 years time scale, the East Asian summer monsoon has a much more significant effect on the flood in northern Henan. The flood disaster tends to occur when the sunspot number reaches or nearly reaches the extreme value, and the occurrence frequency is larger during maximum value M than that during minimum value m. The decade cycle of flood in northern Henan has a significant response to the changes of Sunspot Cycle Length (SCL) at various time scales, while the floods in southern Henan only have a significant response to the changes of SCL at the 100 years time scale, that is, it will be beneficial to reduce the floods in northern Henan when the SCL becomes longer (the sun activity die down), and conversely, it will be conductive to the increasing occurrence of floods. The flood change in Henan province may be the results of the interaction between the solar activity and the East Asian summer monsoon. This paper further revealed that the historical flood occurrence and formation has an important significance for correctly predicting the future trend of drought and flood.