Jiangyin: Jiangnan. In ancient times, the south of water was the shade of trees. Also refers to the south bank of the Yangtze River. In the Southern Dynasties and Song Dynasty, Bao Zhao wrote in the poem "Wangjiang Sunset to Sung Hoon": "When the sun sets, the mountains and clouds return, and the neck is covered with Wangjiang." Liang Jiangyan in the Southern Dynasties wrote "Lotus Fu": "So I was unhappy, and when I went out of Jiangyin, I saw the rosy clouds and the clouds and the dawn." "The Book of the Northern Qi Dynasty Wen Xuandi Ji": "Jiangyin told the disaster and the people were at a loss."
It can also refer to Jiangyin, Jiangsu Province (also a very old name), such as a poem called "Jiangyin Piaoyuantang Nostalgia"
Hanyang: North of Hanshui River (now Hanjiang River). In later ancient prose (late Ming or Qing Dynasty, Republic of China), it was also often called Hanyang City (one of the three towns in Wuhan today).
Huayin: North of Huashan Mountain. And Huayin city.
Hengyang: It only refers to Hengyang City, and there is no ambiguity. Hengyang is named because it is located at the southern foot of Hengshan Mountain and the south of the mountain is "Yang".