1644-2009年黄河中游旱涝序列重建与特征诊断

Research on sequence reconstruction and characteristics diagnosis of droughts and floods in the Middle Yellow River since the Qing Dynasty(1644-2009)

据清代各县级政区的历史沿革,及现存历史文献资料的详细程度,选取黄河中游18个代表站点,在提高空间分辨率的基础上,采用旱涝等级法与面积加权法重建了1644-2009年各站点旱涝等级序列。利用小波分析、累积距平、滑动t-检验等方法,检测了全区过去366年旱涝发生的周期、阶段性和突变点。结果显示:旱涝序列存在21年、70年、114年左右的多年代际尺度周期信号;1644-1683年、1737-1775年、1885-1921年为多雨期,1684-1736年、1776-1814年、1922-2001年为少雨期;目前黄河中游开始进入雨涝多发期;1815-1895年旱涝波动频繁,气候进入不稳定期;过去366年存在2个由干旱转为雨涝期的气候突变点,分别位于1723-1726和1814-1816年。

Based on the existing historical documents and literatures about counties and basin distributions along the Middle Yellow River since the Qing Dynasty, and the research results on droughts and floods, this paper selects 18 representative stations with a high spatial resolution in order to reconstruct the regional grading sequence of droughts and floods from 1644 to 2009. The characteristics including the periodicity, phases, and mutability of droughts and floods over the past 366 years in all the regions are diagnosed by employing the methods of wavelet analysis, accumulative anomaly, and Moving t-test technique. It is believed that droughts and floods have multi-scale periods such as 21-, 70-, or ll4-year; the periods from 1644 to 1683, from 1737 to 1775, and from 1885 to 1921 are pluvial periods; the periods from 1684 to 1736, from 1776 to 1814, and from 1922 to 2001 are less-rain periods; currently, the Middle Yellow River is stepping into another pluvial period. Over the nearly 80 years from 1815 to 1895, droughts and floods occurred frequently, during which the climate change was quite unstable. Throughout the period of time studied in this paper, it is concluded that there are 2 abrupt climate changes from drought periods to pluvial periods.