Siouxland Magazine - Volume 2 Issue 2

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UCELL team
Loess Countries: New US-China collaboration on the Loess Hills
By Graham McGaffin
While U.S.-China relations have been tense
recently when it comes to international trade, one
area that has witnessed a new era of collaboration
and cooperation between the two countries is with
the study of the loess hills and soils. In June, a small
gathering of U.S. and Chinese experts on loess soils and
restoration met in Yangling, Shaanxi Province, China to
share information on the Iowa Loess Hills and the China
Loess Plateau, their condition, value, restoration and
protection, as well as the latest research on loess soils.
Loess (pronounced as “luss,” “Lois,“ or “less”) refers to the
yellowish deposit of wind-blown rock dust found in many
parts of the world, including Germany, Argentina, New
Zealand, the U.S., and China. However, loess deposits of
significant depth (60-350m) and area occur only in two
places: in the Yellow River region in and around Shaanxi
province, China, and in the mini-mountains (bluffs)
of western Iowa. Our Loess Hills parallel the Missouri
River 220 miles from Mound City, Missouri to Westfield,
Iowa. The beautiful sharp-cliffed hills can be seen along
Interstate 29 through the western sides of Fremont,
Mills, Pottawattamie, Harrison, Monona, Woodbury, and
Plymouth Counties. They were formed from glacierground
rock powder brought down the Missouri River
and blown into dunes by westerly winds.
The Chinese Loess Plateau, which covers an area only
slightly less than the entire state of Texas, is located
several hundred miles southwest of Beijing. The loess
there eroded from various mountain areas over millions
View over city of Ansai from Loess Hills
of years, was collected in the Gobi and other deserts, and
from there was blown into the plateau region. Over the
centuries, the Loess Plateau lost much of its vegetation from
overgrazing and deforestation, with the resulting erosion
filling the Yellow River with deposits of so much loess that
devastating flooding of croplands became common—the
name Yellow River originated from the color the water
because of the sedimentation with loess soil.
A huge restoration project funded by the World Bank and
others set out to partially restore the plateau over an area
roughly the size of New Jersey. While the age and size of
the two landforms differ significantly, the natural resource
issues that have challenged China’s loess plateau are not
unlike those facing Iowa’s Loess Hills and Missouri River
system today. Similarly, many of the solutions are also
applicable to both places.