2. According to Zuozhuan, Guoyu and Sima Xiangru's Zixu Fu, there was a hunting ground named Yunmeng in the pre-Qin period. Yunmeng has a vast territory, bounded in the east by the foot of Dabie Mountain, Shogun Mountain and even the banks of the Yangtze River east of Wuhan, in the west by Yichang and Yidu, including Songzi and Gongan counties south of the Yangtze River, in the north by Suizhou, Zhongxiang and Jingshan, and in the south by the Yangtze River. There are various geographical forms such as mountains and rivers, and there is a lake called "Yunmengze". "Yunmengze" is named after "Yunmeng", and they do not refer to the same concept. In the Spring and Autumn Period, dream means "Lake Ze" in Chu language, which is related to Sui. Due to the siltation of the Yangtze River, Yunmengze was divided into two parts, and the north of the Yangtze River became a swamp, while the south of the Yangtze River still maintained a vast water surface.