The Yangtze River flows eastward, carrying hundreds of millions of sediment and nearly a trillion cubic meters of water to the sea every year, and finally creates a beautiful oasis at the confluence of the river and the sea - Chongming Island.
Chongming Island, located at the mouth of the Yangtze River, has a total area of more than 1,200 square kilometers, ranking the third largest island in China and the world's largest estuarine alluvial island.
It is not only a summer resort in Shanghai, known as the "Gateway of the Yangtze River" and the "Back Garden of Shanghai", but also has a mysterious and beautiful name - Yingzhou in the East China Sea.
It is said that this place, known as an overseas fairyland, has not been found for thousands of years, until Zhu Yuanzhang, the Taizu of the Ming Dynasty, made the capital of Nanjing, in order to pray for good luck, he gave this name to Chongming Island, making this legendary fairyland settle here.
The beautiful scenery of Chongming Island is like a living fossil of the vicissitudes of the sea, which is very commensurate with the immortal Ling Ran name of "Yingzhou in the East China Sea". Chongming Island is seventy or eighty kilometers long from east to west and more than ten kilometers wide from north to south, and its shape is like the imprint of a large sole.
Its formation is not a day's work, but a "peerless masterpiece" carefully carved by the water of the Yangtze River after thousands of years of history.
The geographical location of Chongming Island changed dramatically two or three thousand years ago. At that time, the mouth of the Yangtze River was far away in the area of Zhenjiang and Yangzhou, and the two mouths were far apart, and the estuary was in the shape of an open trumpet.
Under the influence of the Coriolis force, when the Yangtze River Estuary was advancing eastward, the north mouth was changeable, and the south mouth moved steadily eastward, and the evolution of the Yangtze River Estuary formed a complex and changeable historical map.
In the pre-Qin era, there was still a vast sea east of Rugao, and now there is a sandbar in the sea in the east of Rugao, called Fuhaizhou.
In the pre-Qin period, during the Eastern Jin Dynasty and the Northern and Southern Dynasties at the mouth of the Yangtze River, Fuhaizhou and Rugao land were gradually connected, forming a new sand spit on the north bank of the Yangtze River, making the river shoreline extend from Rugao to Rudong.
This is the first time that the north bank of the Yangtze River estuary has been connected to the mainland by a sandbar outside the mouth. At the same time, in the location of the main urban area of Nantong City, a new large sandbar has appeared in the sea area south of the North Mouth - Hu Tuozhou.
Dating back to the reign of Gaozu Wude of the Tang Dynasty, the North Mouth of the Yangtze River Estuary formed a sandbar with land for the first time. The influence of the tidal zone makes the sea area southeast of Hushuzhou ** Dongsha and Xisha two sandbanks, separated by more than 70 miles, which is the predecessor of Chongming Island.
Dongsha is located in the area of Xianghua Town and Chenjia Town in the eastern part of present-day Chongming Island, while Xisha is located in the area of Chengqiao Town in the central part of present-day Chongming Island.
In the past few decades, Dongsha and Xisha have gradually stabilized and increased, attracting more and more coastal residents to settle and reclaim. During the Five Dynasties, the mouth of the Yangtze River was the border between Wu and Yue and Southern Wu, and the two sides frequently clashed here.
In order to consolidate its rule, Southern Wu established the town of Chongming in Xisha, which is the origin of the name Chongming. It can be seen that the degree of development of Xisha was higher than that of Dongsha at that time.
At the beginning of the 10th century, Hushuzhou was connected to the Rugao continent in its northwest, which was the second sandbar connection at the northern mouth of the Yangtze River. By the middle of the 11th century, Dongbuzhou was also connected to the Nantong mainland, and the north mouth of the Yangtze River extended to the area of Lusigang in today's Qidong City.
These changes have affected the Gubei River at the mouth of the Yangtze River, making the east and west sands a new dividing point, and the sandbars in the surrounding waters have also risen faster and larger. Under the influence of Coriolis force, the sandbar of the Yangtze River estuary still showed a trend of silting in the north and collapsing in the south, so the development of Chongming Island in the Song Dynasty started from Dongsha and gradually expanded to the northwest.
In the third year of Tiansheng in the Northern Song Dynasty, a sand rose out of the northwest of Dongsha, named Yao Liusha, and later it extended to the southeast and bordered Dongsha that expanded westward, merging into a larger sandbar.
In the first year of the Yasukuni Dynasty, a large sandbar appeared in the middle of the river, which was 50 miles northwest of Yao Liusha, which was called Sansha. Because Sansha is under the jurisdiction of Chongming Town, Xisha, it is also known as Chongming Sand.
During the Song and Song dynasties, the topography of Dongsha, Yaoliusha, Xisha and Sansha laid the foundation for the formation of Chongming Island. In the fifteenth year of Jiading in the Southern Song Dynasty, Song ** set up a Tianci salt field in Yao Liusha.
In the fourteenth year of Yuan to Yuan, Tianci Salt Field was further developed, and it was renamed Chongming Prefecture under Yangzhou Road, and Sansha Town was established in Sansha, and Xisha was demoted from the town to the Inspection Division.
In the second year of Hongwu in the Ming Dynasty, Chongming Prefecture was downgraded to Chongming County. These facts show that since the Southern Song Dynasty, the Dongsha-Yaoliusha consortium has surpassed Xisha in terms of local politics and economy, and it also proves that the theory that Dongsha and Xisha collapsed during the Northern Song Dynasty is not accurate.
It can be inferred from the "Attached Map of Chongming County in the Chronicles of Suzhou Prefecture of Hongwu of the Ming Dynasty" that Sansha had been connected with Dongsha-Yao Liusha long before the Ming Dynasty to form a larger sandbar.
Under the influence of long-term sediment deposition in the Beiqi Road of the Yangtze River estuary, many new sandbanks appeared in the Ming and Qing dynasties, as can be seen from the attached map of Chongming County Chronicles of Ming Zhengde below, there were many sandbanks in the Beishan Road at that time, which can be roughly divided into three sandbar groups centered on Dongsha-Yaoliusha-Sansha Complex, Xisha and Pingyangsha.
Chongming Island was finally formed in the late Ming and early Qing dynasties, during which it went through many sandbar mergers. First, the Changsha and Yaoliusha associations on the Xisha wreckage merged into one island, and then the Pingyang sand group also joined in, and finally the shape of Chongming Island was basically stabilized.
The history of the formation of Chongming Island is a vivid history of the transformation of the vicissitudes of the sea, in which the rise and fall of the sandbar and the migration of the county seat have left a deep imprint. The establishment of Chongming County began in the 14th year of the Yuan Dynasty (1277), and has undergone five migrations and six restorations, each of which is a witness to history.
Especially in the late Qing Dynasty, in order to resist erosion, the local people built a strong stone embankment in the south of the county to keep the county seat. The history of Chongming Island's rise is like a realistic script, revealing the power of nature and human activities.