According to a history book, Qin Shihuang sent people overseas to look for the elixir of life, but in the end these people didn't come back, and this book only recorded the story about Han Zhongdong's crossing to South Korea. In Chen Han, south of the Korean peninsula, it is said that Chen Han had a close relationship with the Qin people at that time. Chen Han is also called Qin and Han Dynasties. In Korean, it is pronounced the same as Qin.
During the Qin and Han Dynasties, due to exorbitant taxes and levies, many Han Chinese in the Central Plains immigrated to the Korean Peninsula and the Japanese archipelago, which is probably a typical migration event of Han Chinese in the Central Plains in this period. At that time, the Han people took the same name in Korea as their hometown because they were homesick.
Another way of saying this is that both Hubei and South Korea have the Han River. Just like the Han River in China, where the river flows, it breeds a large area of land and population. This river has a special meaning just like the mother river, so Koreans like to use related words such as "Jiang" and "Han" to name it, and it is inevitable to have the same name.
There is also a saying that South Korea is close to China and deeply influenced by China culture. During the prosperous Tang Dynasty, South Korea greatly admired China culture. In ancient times, South Korea liked to learn from China, especially the Hanshui culture, and the mountains and rivers culture in the north of our country was also admired by them. Therefore, many names of the Hanshui River Basin have also been imitated by them, such as Xiangyang and Hanjiang River, which can be seen in Korea.