As a result of centuries of farming, the landscape has become scarred with thousands of water-worn gullies. But this spectacular erosion has had an unexpected benefit. The streams which drain the gullies carry the fertile yellow soil into the plateau's major river, known to the Han people as the Mother of Chinese civilisation.


北京一直以来都依赖着中国的北部平原，这块肥沃土地接近英国国土面积的两倍。北部平原的肥沃起源于更远的西部黄土高原，黄土高原的富矿土壤，难以置信地富饶。人们已经在这儿生活了数千年，在软土中抠建而成了他们的住所。窑洞也许缺乏北京一样的魅力，对这儿的人们来说却是生活的一部分。不但温暖而且安全，最好的是能够吃得饱。