[Academic] The water in the south of Shannan is Yang in the north. Why is Hanyang in the south of Hanshui?

It is an ancient place name of South Korea, and now it is the seat of the capital of South Korea. It's called Seoul, which is Seoul. 14-15th century, the Korean regime changed, and the aristocratic forces headed by Li Chenggui replaced the Wangs' Koryo and established a new dynasty. According to the requirements of the new dynasty and the approval of Emperor Chengzu of the Central Plains, the emerging dynasty used the name of the first formed country on the ancient peninsula-Korea, which means "the land of bright sun and sunrise". The Li Dynasty was founded in 1392, and moved to Yangzhou in 1394. In order to express his admiration for the Han Dynasty in the Central Plains (not the Han Dynasty) and his determination to "serve the Han Dynasty wholeheartedly", Li Chenggui wrote to Zhu Yuanzhang, demanding that Yangzhou be renamed "Seoul", that is, "hansung" in English. Because Seoul is located on the north bank of the Han River, the city is also called Hanyang according to the geomantic principle of "Hebei is Yang". There is a university in Korea called "Hanyang University", from which the name comes.