China's Physical Regions and River Systems

Chinese geographers commonly describe the country's topography as a "three-step staircase" (san ji jieti) descending from west to east. The first and highest step is the Qinghai-Tibet Plateau, averaging more than 4,000 meters in elevation and often called "the roof of the world," bordered by the Kunlun and Himalaya ranges. The second step, at roughly 1,000 to 2,000 meters, includes the Inner Mongolian Plateau, the Loess Plateau, the Yunnan-Guizhou Plateau, and the great interior basins of Xinjiang: the Tarim Basin, home to the Taklamakan Desert and Silk Road oasis towns such as Kashgar and Khotan, and the Junggar Basin to its north, separated by the Tian Shan range. The third step, generally below 500 meters, comprises the fertile eastern lowlands — the North China Plain, the Sichuan Basin, and the middle and lower Yangtze plains — where the overwhelming majority of China's population and agricultural output is concentrated. This staircase structure was shaped over tens of millions of years by the collision of the Indian and Eurasian tectonic plates, which continues to uplift the Himalaya and Tibetan Plateau by a few millimeters annually.