江汉平原近3000年来古洪水事件的沉积记录

Sedimentary Records of Paleoflood Events During the Last 3000 Years in Jianghan Plain

洪水发生规律是洪灾预报的前提,已有的历史洪水记录时间尺度不足以认识和把握洪水的出现规律。因此,利用地质记录延长洪水时间序列,从地质记录中认识洪水的发生规律,显得非常重要和必要。江汉平原江陵地区的洪水地质记录表明,近3000年来,该区共发生了18次特大洪水漫滩事件。这些古洪水的频发与湿冷气候相对应。功率谱分析发现古洪水漫滩事件包含26、31、36、43、52、79、110年这样的周期。分析表明江陵地区古洪水发生的驱动因子可能是太阳活动。

It is well known that paleoflood predictions must depend on its occurrence rule. However, available historical records do not provide long enough temporal scale for identification of emergence law of flood events. It is very important and necessary to discover and understand floodwater geological records. The pluvial geological records of Jiangling area in Jianghan Plain, show that the area revealed 18 flood events during the last 3000 years. The paleoflood events corresponded to cold and wet climate. With the help of power spectral analysis, it is found that paleoflood events include 26, 31, 36, 43, 52, 79, 110 a cycles. It is indicated that solar activity may be driving factor of paleoflood in Jiangling area.