What are the geographical divisions of China?

According to the characteristics of geographical location, physical geography and human geography, China can be divided into four geographical regions, namely, northern region, southern region, northwest region and Qinghai-Tibet region. Among them, Qinling Mountain and Huaihe River are the dividing lines between the northern region and the southern region. Daxinganling-Yinshan-Helan Mountain is the dividing line between the northern region and the northwest region. The dividing line between the Qinghai-Tibet region and the northwest, north and south regions of China is roughly the dividing line between the first step and the second step.