27. China’s Loess – A Blessing and a Curse
China’s Loess Region is a plateau covering about 250,000 square miles in northern China, along the upper and middle Yellow River Valley. The good thing about the region is that the soil that gave it its name and covers the ground in layers up to 300 meters deep, is great for farming. Loess is porous, with small empty spaces in the soil that allow for excellent air circulation. It is also friable – that is, easy to break into smaller pieces. That makes loess fields relatively easy to plough, requiring less time and effort from farmers.
On the other hand, the very factor that makes loess attractive to farmers and conducive to high population densities – the ease with which it breaks and crumbles – is also a vulnerability. Loose soil might be great for farming, but buildings erected atop it are particularly prone to tumbling down if the ground shakes. Unfortunately, the ground in the Loess Region has a tendency to shake.