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Catastrophic Hydrologic Events of the Holocene in the Middle Reaches of China's Yellow River
Reference
Huang, C.C., Pang, J., Zha, X., Su, H., Jia, Y. and Zhu, Y. 2007. Impact of monsoonal climatic change on Holocene overbank flooding along Sushui River, middle reach of the Yellow River, China. Quaternary Science Reviews 26: 2247-2264.

What was done
The authors constructed a complete catalog of Holocene overbank flooding events at a watershed scale in the headwater region of the Sushui River within the Yuncheng Basin in the southeast part of the middle reaches of China's Yellow River, based on pedo-sedimentary records of the region's semiarid piedmont alluvial plains, including the color, texture and structure of the sediment profiles, along with determinations of particle-size distributions, magnetic susceptibilities and elemental concentrations.

What was learned
There were six major episodes of overbank flooding. The first occurred at the onset of the Holocene, the second immediately before the mid-Holocene Climatic Optimum, and the third in the late stage of the mid-Holocene Climatic Optimum, while the last three episodes coincided with "the cold-dry stages during the late Holocene," according to the six researchers. They also note that "during these three episodes there were not only catastrophic floods, but also extreme droughts over the middle and lower reaches of the Yellow River drainage basin."

Speaking of the last of the overbank flooding episodes, they note that it "corresponds with the well documented 'Little Ice Age,' during which there were frequent natural disasters including catastrophic floods, droughts, dust storms, heat waves, migratory locusts and frequent famines and plagues in the middle-lower reaches of the Yellow River drainage basin," when "climate departed from its long-term average conditions and was unstable, irregular, and disastrous," which is pretty much like the Little Ice Age has been described in many other parts of the world as well.

What it means
Once again, scientists have uncovered a situation where some -- if not most -- of the most disastrous periods of the Holocene occurred during colder as opposed to warmer times.

Reviewed 16 April 2008