Sedimentary and hydrological studies of the Holocene palaeofloods in the Shanxi-Shaanxi Gorge of the middle Yellow River, China
Sedimentary and hydrological studies of the Holocene palaeofloods in the Shanxi-Shaanxi Gorge of the middle Yellow River, China
复制标题
黄河中游晋陕峡谷全新世古洪水沉积与水文研究
DOI：
10.1007/s00531-014-1067-9
复制
发表时间：
2015-01-01
影响因子：
2.3
通讯作者：
Ma, Yugai
中科院分区：
文献类型：
--
作者：
Li, Xiaogang;Huang, Chun Chang;Ma, Yugai
全新世静水沉积物沿着河道被用来研究的规模和频率的古洪水之前发生的测量和历史数据集在世界各地。黄河中游晋陕峡谷沿着的古水文调查发现，沿河道边缘的悬崖沿着有古森林滞水沉积。SWD被插入在全新世风成黄土-土壤剖面和碎屑斜坡沉积物中。根据磁化率和粒度分布等沉积标准和分析结果，将古森林SWD与风成黄土和土壤区分开来，这与2012年洪水SWD相似，表明这些分选良好的古森林SWD层是由洪水中的悬浮泥沙沉积而成的。他们记录了黄河流域3200 ~ 3000 aBP之间的异常古气候事件，并与前人研究的全新世土壤地层进行了对比。曼宁斜率面积计算估计，这些古冰川事件的峰值流量范围为43，290至49，830 m（3）/s。研究区流域面积489，900 km（2）。这是自1934年以来发生的最大洪水（21，000 m（3）/s）的2.0-2.5倍。这些事件也发生在黄河支流，包括渭河，泾河和淇水河。因此，这些洪水事件被认为是北方已知气候事件的区域表现，并表明全新世气候不稳定。该研究为了解半干旱半湿润地区区域水文气候系统与全球变化之间的相互作用提供了重要数据。
Holocene slackwater deposits along the river channels were used to study the magnitude and frequency of the palaeofloods that occurred prior to gauged and historical data sets all over the world. Palaeohydrological investigations along the Shanxi-Shaanxi Gorge of the middle Yellow River, China, identified palaeoflood slackwater deposits (SWDs) at several sites along the cliffs bordering the river channel. The SWDs are intercalated within Holocene eolian loess-soil profiles and clastic slope deposits. The palaeoflood SWDs were differentiated from eolian loess and soil by the sedimentary criteria and analytical results including magnetic susceptibility and particle-size distribution, similar to the flood SWDs in 2012, which indicated that these well-sorted palaeoflood SWD beds were deposited from the suspended sediment load in flood-waters. They have recorded the extraordinary palaeoflood events which occurred between 3200 and 3000 a BP as dated by the optically stimulated luminescence method in combination with pedostratigraphic correlations with the previously studied Holocene pedo-stratigraphy in the Yellow River drainage basin. Manning slope-area calculations estimate the peak discharged for these palaeoflood events to range from 43,290 to 49,830 m(3)/s. The drainage area of the study site is 489,900 km(2). It is 2.0-2.5 times the largest gauged flood (21,000 m(3)/s) that has ever occurred since 1934. These events also occurred on Yellow River tributaries, including the Weihe, Jinghe and Qishuihe Rivers. These flood events are therefore considered to be a regional expression of known climatic events in the northern hemisphere and demonstrate Holocene climatic instability. This study provides important data in understanding the interactions between regional hydro-climatic systems and global change in semiarid and subhumid regions.