Қытайдың сары топырақ аймағындағы жер астындағы үйлер

Form of Earth Shelter Dwelling in the Loess Plateau

A yaodong (natively 窰 in Jin Chinese, or 窰洞 yáodòng in Beijing Mandarin) is a particular form of earth shelter dwelling common in the Loess Plateau in China's north. They are generally carved out of a hillside or excavated horizontally from a central "sunken courtyard". The earth that surrounds the indoor space serves as an effective insulator, keeping the inside of the structure warm in cold seasons and cool in hot seasons. Consequently, very little heating is required in winter, and in summer, it is as cool as an air conditioned room. The history of yaodongs goes back centuries, and they continue to be used. In 2006, an estimated 40 million people in northern China lived in yaodongs.

The first yaodongs were underground dwellings that date back to the 2nd millennium BC, China's Bronze Age, and according to Chinese tradition, the Xia Dynasty. Chinese scholars generally believe that this type of habitat was developed mainly from the Han dynasty (206 BC to 220 AD) on, along with a progressive improvement of construction techniques during the Sui (581 to 618) and Tang (618 to 907) dynasties. During the dynasties Ming (1368 to 1644) and Qing (1644 to 1912), the pace of construction reached its peak.

The yaodong homes are common on the Loess Plateau of China in the North, and are found mainly in five provinces: Gansu, Shaanxi, Shanxi, Henan, and the Hui Autonomous Region of Ningxia. In the Qingyang region, the ratio of cave dwellers to non cave dwellers is the highest found anywhere in China. The death toll of approximately 810,000 from the 1556 Shaanxi earthquake was in part because it was centered on the Loess Plateau, and collapsed many yaodongs.

More elaborate yaodongs may have a façade built with stones with fine patterns carved on the surface. Yaodongs can also be constructed with stones or bricks as stand alone structures. The inside walls are usually plastered with lime to make them white. Different types of yaodong have varying construction processes. For the cliffside yaodong, the main structure is the soil wall, and the interior is reinforced with wooden piles. The beams and columns bear the load, forming a structure intended to prevent the cave from collapsing. The usual method of this construction process is to use rock for the wall base, and clay as the top tile. In order to reinforce the cave and reduce costs, walls are made of clay inside and stones outside. Building a hoop yaodong requires a wood frame mold. Because the wood mold can be reused, and the wood consumed is limited, the overall cost can be lower than that of most housing. Moreover, because its space volume is 1/3 smaller than that of a regular house, the hoop yaodong has a strong advantage in energy conservation. The first step in the construction of a hoop yaodong is to dig the foundation, after determining the orientation. Then, the entrance position and the height and thickness of the wall is determined based on the orientation. A hoop yaodong usually has three or five caves. The second step is to excavate the cave. Because a hoop yaodong is built on flat ground, the excavation uses the existing brick wall to make the arch structure, creating the basic spatial form of each cave. The yaodong is covered with at least two meters of mud to ensure the thermal insulation of the cave. The top of the cave is normally capped with a normal house structure. The third step is to build the fence and install doors.

The most famous yaodongs in China are perhaps those in Yan'an. Edgar Snow visited Mao and his party in Yan'an and wrote Red Star Over China.