What are the "three articles and four pillars" put forward by scholars in the Han Dynasty?

After the pre-Qin philosophers roughly demarcated the mountains and rivers of Yugong, the Han philosophers founded the famous "Three Articles and Four Columns Theory" on this basis.

They are:

Beitiao: Dunzhi (north bank of Weihe River in Shaanxi)-Jingshan-Hukou-Leidao (between Shaanxi and Shanxi)-Taiyue-mainstay-Xicheng-Wuwang (south of Shanxi)-Taihang-Hengshan-Guishi (Hebei)

Medium-length: Xi-Zhu-Bird and Mouse-Taihua (Longshan) Bear Ear-Foreign Party-Tongbai-Companion Tail (Lunan). Sub-bureau: Panzhong (southern Shaanxi)-Jingshan-Waiwai-Dabie (Hubei, Anhui)

Southern zone: Minshan-Hengshan-Fushanyuan (Lushan)

The first column: Wa-Jieshi (that is, the northern column)

Article 2: tilt to the west-with the tail (that is, the middle trunk)

Article 3: intraday-big difference (that is, middle branch)

Article 4: Minshan-Fushan Source (i.e. Nantiao)