China Loess Plateau
The Loess Plateau also known as the Huangtu Plateau, is a plateau that covers an area of some 640,000 km² in the upper and middle of China's Yellow River and China proper . Loess is the name for the silty sediment that has been deposited by wind storms on the plateau over the ages. Loess is a highly erosion-prone soil that is susceptible to the forces of wind and water; in fact, the soil of this region has been called the "most highly erodible soil on earth".The Loess Plateau and its dusty soil cover almost all of Shanxi, Shaanxi, and Gansu provinces, the Ningxia Hui Autonomous Region, and parts of others.
In ancient times, some of the earliest recorded mention of this area is from travel along the Northern Silk Road. In the last part of the first millennium BC, after the explorer Zhang Qian's return to China, the Han Dynasty pushed the Xiongnu back and trade and cultural exchange flourished along the Northern Silk Road through the southern Loess Plateau. Goods moving by caravan to the west included gold, rubies, jade, textiles, coral, ivory and art works. In the opposite direction moved bronze weapons, furs, ceramics and cinnamon bark.
Historically the Loess Plateau has provided simple yet insulated shelter from the cold winter and hot summer in the region, as homes called yaodong were often carved into the loess soil; in medieval times of china people stayed here to grow rice; some families still live in this kind of shelter in modern times. During the Shaanxi Earthquake, nearly a million people were killed as a result of collapsing loess caves. The yaodongs that are best-known to the world are perhaps those in Yan'an where the Communist Party led by Mao Zedong headquartered in 1930s. When Edgar Snow, the author of Red Star Over China, visited Mao and his party, he lived in a yaodong.
The Loess Plateau was highly fertile and easy to farm in ancient times, which contributed to the development of early Chinese civilization around the Loess Plateau.
Centuries of deforestation and over-grazing, exacerbated by China's population increase, have resulted in degenerated ecosystems, desertification, and poor local economies.
In 1994 an effort known as the Loess Plateau Watershed Rehabilitation Project was launched to mitigate desertification; limited success has resulted for a portion of the Loess Plateau, where now trees and grass have turned green and farmers are busy in their croplands. A major focus of the Project was to try and guide the people living in the Plateau to use more sustainable ways of living such as keeping goats in pens not being allowed to roam free and erode the soft silty soil found in the plateau. Many trees were planted and nature is now reclaiming a portion of the Loess Plateau. Results have reduced the massive silt loads to the Yellow River by about one percent.
The Loess Plateau was formed over long geologic times, and scientists have derived valuable information about global climate change from samples taken from the deep layer of its silty soil.