| on Apr 25, 2008, 01:39 PM E.S.T.
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In nearly every presentation on global warming, we hear that floods
and droughts will be more severe as the temperature rises. Believe it
or not, and who would not believe it given thousands of websites on the
issue, there are many scientists who believe the opposite. We have
covered these topics in many previous essays, and a recent article in Quaternary Science Reviews reinforces our skeptical viewpoint.
The research was conducted by Chun Chang Huang and five associates
from China’s Shaanxi Normal University. Their goal was to reconstruct
major flooding events of the Sushui River (Figure 1) during the
Holocene period (the Holocene began approximately 12,000 years ago when
the last great glacial period ended).
Huang et al. explain “In semiarid zones, the piedmont alluvial
plains are episodically inundated by overbank floodwater during heavy
rainstorms.” They also state “However, in the semiarid loess region in
the middle reaches of the Yellow River drainage basin, the elevation of
alluvial plains also increases through dust accumulation, which is
commonly followed by soil formation that together separate fluvial
deposits produced during episodes of overbank flooding. Fine-grained
slackwater deposits of the floods are therefore preserved between the
architecture of loess and soils which also protect these flood deposit
from subsequent erosion by overland water flows, wind erosion, and
human activities.” Basically, they found a geomorphic sequence that
beautifully preserves datable information about major floods over the
past 12,000 years. They write “Thus, these loess–soil sequences provide
unique information for investigation of Holocene climatic change, flood
hydrology, geomorphic and pedogenic changes, and human impact in
semiarid zones. This stratigraphic data can provide valuable hydrologic
information to those working in engineering hydrology, flood hazard
prevention and mitigation, geomorphology, Quaternary sciences and
global change.”

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