Since it was recorded in literature, the Yellow River has often been flooded and diverted. According to the statistics of the Yellow River Conservancy Commission 1959, the Yellow River burst more than 1500 times in the historical period, and there were 26 major diversions. Among these 26 major diversions, 6 have great influence, involving Henan, Hebei, Shandong, Anhui and Jiangsu provinces.
The first major diversion of the Yellow River recorded in the history books was in the third year of the establishment of People's Republic of China (PRC), a new dynasty of Wang Mang (1 1). The Yellow River burst in the southwest of Linzhang County, Hebei Province, and it took more than 60 years to form a new channel. This river divides from the old river of the Western Han Dynasty in Puyang, Henan, passes through Liaocheng, Yucheng and other counties in Shandong, and enters the sea near Lijin County in Shandong. This river has been used for hundreds of years and has not changed much. The second diversion was in the eighth year of Zong Qinghou in Hongren (1048), and the Yellow River burst again in Puyang County, Henan Province. After the river overflowed, it was divided into two veins: one flowed northward into Yongji Canal, and now it enters the sea near Tianjin; Another vein flows eastward into the sea in Wudi County, Shandong Province today. Until the second year of Song Zhezong Fuyuan (1099), the eastward flow was cut off, and the whole river flowed northward, forming another new channel. In the second year of Jianyan in Song Gaozong (1 128), in order to prevent the nomads from going south, the Song Dynasty decided to cross the river in the southwest of hua county, Henan Province. The new river passes between the south of hua county and Puyang and Dongming counties, and then flows into Surabaya through the four counties of Juancheng, Julu, Jiaxiang and Jinxiang, Shandong Province. From here, it enters the Huaihe River and captures the Huaihe River into the sea. This is the third major diversion of the Yellow River, and it is also the first time in history that the Yellow River flows south to seize the Huai River and enter the sea. The fourth major diversion of the Yellow River was in the early Yuan Dynasty. Compared with the previous times, the shunt time is long and there are many branches. When the state of Jin was about to perish, the Mongolian army attacked Defu (now Shangqiu County, Henan Province), and in the northwest of Shangqiu County, the river seized water and entered Si. Later, the Mongolian army broke the river in the north of Kaifeng, and the river seized vortex water and entered the Huaihe River. Shortly after this diversion, in the 23rd year of the Yuan Dynasty (1286), the Yellow River was implemented in Yuanyang, Zhongmou, Yanjin, Kaifeng, Qixian, Suixian, Chenliu, Tongxu and Taikang counties. It is speculated that the Yellow River was divided into three shares in Yuanyang County at that time: one share entered Surabaya from Xuzhou via Chenliu, Qixian and Suixian; One flows southwest in zhongmou county, passes through Weishi, Weichuan, Yanling, Fugou and other counties, and enters the Huaihe River from Shui Ying in northern Anhui. One runs south of Kaifeng, passes through Tongxu, Taikang and other counties, and flows into Huaihe River from vortex water in northern Anhui. This is the fifth major diversion of the Yellow River and the largest river migration in history. * * * River invades four rivers (Ying, Si, Vortex and Huai) and enters the sea. Flooded rivers are all over the vast areas of central Henan, Anhui and northern Jiangsu. The last major diversion of the Yellow River was in the fifth year of Xianfeng in Qing Dynasty (1855). This year, the Yellow River has decided a new channel in Tongwa Room, lankao county. This is the river seen on the map today.
Judging from the diversion of the Yellow River mentioned above, the northernmost part of the Yellow River entering the sea is near Tianjin, and the southernmost part enters the sea together with Huaishui. If we make a triangle with the present Mengjin County, Henan Province, the present Tianjin City and the place where the Huaihe River enters the sea as three vertices, most of the land of this triangle will leave the footprints of the Yellow River wandering.
To sum up, the Yellow River entered the Bohai Sea in the Tang Dynasty.