It seemed somewhat plausible to me until I found studies that do not support the first thesis. An example is [1], apud [2] (I've got no access to the original article), where Chinese scientists found this:

Their discussion of flooding and usually cold period continued for the other episodes; they state "The overbank flooding episodes temporally overlap with the cold-dry stages. It implies that during these three episodes both extreme floods and droughts occurred in the tributaries and the mainstream of the Yellow River in its middle and lower reaches." They found flooding during the Little Ice Age stating "During the sixth episode of overbank flooding on the piedmont alluvial plain, 73 out of 110 catastrophic floods on the Sushui River in the Yuncheng Basin during the last 2200 years occurred between the 14th and 19th centuries. Extreme overbank flooding on the Sushui River occurred in AD 1570, 1662, 1745 and 1761, each resulting in hundreds of fatalities and inundation and devastation of thousands of villages and towns."

Furthermore, they found "Our data show that the last three episodes of overbank flooding, including the catastrophic floods recorded in literature, coincide with the cold-dry stages during the late Holocene. 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. For example, the last episode of overbank flooding event 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. Climate departed from its long-term average conditions and was unstable, irregular, and disastrous during these anomalous episodes."

They conclude "The persistence of geomorphic stability on the piedmont alluvial plain and the absence of overbank flooding during the mid-Holocene Climatic Optimum provide evidence that extreme floods were uncommon in the warm-humid period dominated by the southeastern maritime monsoon."

J M

References

[1] Impact of monsoonal climatic change on Holocene overbank flooding along Sushui River, middle reach of the Yellow River, China. Chun Chang Huang a,b, Jiangli Pang a, Xiaochun Zha a, Hongxia Su a, Yaofeng Jia a and Yizhi Zhu b. Quaternary Science Reviews, Volume 26, Issues 17-18, September 2007, Pages 2247-2264. doi:10.1016/j.quascirev.2007.06.006

a Department of Geography, Shaanxi Normal University, Xian, Shaanxi, PR China
b State Key Laboratory of Loess and Quaternary Geology, CAS, Xian, Shaanxi

[2] World Climate Report: Floods and Droughts and Global Cooling? April 24, 2008. http://www.worldclimatereport.com/index.php/2008/04/24/floods-and-droughts-and-global-cooling/

World Climate Report is in the skeptical side. World Climate Report About Us (http://www.worldclimatereport.com/index.php/about-us/):

Acclaimed by those on both sides of the global warming debate, World Climate Report has become the definitive and unimpeachable source for what Nature now calls the "mainstream skeptic" point of view, which is that climate change is a largely overblown issue and that the best expectation is modest change over the next 100 years.