Chapter 27 Section 5 Dredging River Courses in Yuan, Ming and Qing Dynasties

The lower reaches of the Taihu Lake Basin, with flat terrain, flow into the East China Sea in the east, the Yangtze River in the northeast, and the Hangzhou Bay in the southeast. Due to the small gradient and the top support of the tide, the flood discharge is slow.And because the economic benefits of polders are very good, some high-ranking officials often rely on their power to forcibly build polders in lake areas and rivers, which reduces the lake's water storage capacity and makes it more difficult for waterways to discharge floods. As a result, flood disasters increase sharply.Mr. Miao Qiyu, who is close to me, according to historical statistics, the frequency of floods in the Tang, Song, Yuan, Ming and Qing dynasties in the Taihu Lake Basin is: once every 20 years in the Tang Dynasty, once every six or seven years in the Northern Song Dynasty, once every four to nine years in the Southern Song Dynasty, once every three to five years in the Yuan Dynasty, and once every year in the Ming Dynasty. Once every three to seven years, once every four years in the Qing Dynasty.Therefore, the Yuan, Ming, and Qing dynasties all took dredging the waterways in the lower reaches of the Taihu Lake Basin as the focus of farmland water conservancy work here.

According to historical records, during the more than 90 years of the Yuan Dynasty, the river in the lower reaches of Taihu Lake was dredged no less than a hundred times, about once a year on average.In ancient times, the Wusong River was the most important channel for flood discharge in the Taihu Lake Basin. Jia Qiao, a Song native who has deep research on the water conservancy of Taihu Lake, said that the Wusong River "is as deep and wide as it used to be, rivaling Qianpu".Therefore, the main object of dredging in the Yuan Dynasty was this waterway.Among them, there are two treatments, and the effect is better.One was in the first year of Dade in the Yuan Dynasty (1297 A.D.), presided over by Pingzhang Cheri (Mongolian) in Jiangsu and Zhejiang provinces.There are tens of thousands of military workers engaged in this project. They removed a large amount of sediment transported by tides deposited in the Wusong River Estuary, thereby restoring the flood drainage function of the Wusong River.The other time was in the eighth year of Dade in Yuan Dynasty (AD 1305). It was presided over by Ren Renfa, a famous water conservancy expert at that time and Cheng Cheng of the capital water supervisor. The more serious 38-mile river road.

In the Ming Dynasty, the economy of the Taihu Lake Basin continued to develop.It pays the country's summer and autumn taxes every year. Only the four prefectures of Suzhou, Songjiang, Changzhou, and Zhenjiang in the north are as high as 5 million shi, which is about the sum of the two major tax-paying provinces of Shandong and Huguang (Hubei and Hunan) at that time, accounting for the entire country. One-sixth of the total 29 million shi of the two taxes.The Taihu Lake Basin was the economic lifeline of the Ming Dynasty, and floods and droughts were very serious at that time, especially floods, so the Ming Dynasty government had to use greater power to control the waterways here.The Ming Dynasty lasted 276 years, focusing on the dredging of river drainage, and more than 1,000 constructions were carried out in the Taihu Lake Basin.

Among the frequent dredging projects in the Taihu Lake Basin in the Ming Dynasty, the most important one was presided over by Xia Yuanji, the minister of household affairs in the first year of Yongle (1403 A.D.).He believes that the key to water control in the Taihu Lake Basin is to dredge the downstream channels so that the flood can flow smoothly into the sea.It is also believed that the downstream of the Wusong River is seriously silted up, and the cost of re-dredging is too high.Therefore, he led more than 100,000 river workers, not only focusing on opening Xiajiapu, diverting the water from the upper reaches of the Wusong River, and entering the Yangtze River through the Liujia River; , especially the water from the west of Zhejiang, which is discharged into the Yangtze River along the Huangpu River.This water control not only improved the drainage situation in the lower reaches of Taihu Lake, but also changed the drainage pattern, from the Wusong River as the main drainage channel to the Huangpu River as the main drainage channel. This situation has continued to this day. .

Following Xia Yuanji, Zhou Chen, Xu Guan, Li Chongsi, Lin Yingxun, Lu Guangxun, Hai Rui, etc. all had large-scale governance of the Taihu Lake waterway, and they all played a certain role in flood drainage. more significant.Lin Yingxun presided over the management of the Taihu Lake waterway in the fifth to eighth years of Wanli (AD 1577-1580), with the strong support of the academician Zhang Juzheng.He believes that although the Huangpu River and Liujia River in the lower reaches of Taihu Lake can discharge water, there are still many floods, which are related to the silting of the Wusong River, the main discharge channel in history.Therefore, his water control focused on dredging the Wusong River, and also dredged a number of other waterways such as the Huangpu River and Baimao Port.Successively dredged 140 miles of Wusong River, more than 90 miles of Huangpu River, 45 miles of Baimao Port, and dozens of other ports.This is a relatively comprehensive treatment of the Taihu Lake waterway, the project quality is also good, and the flood discharge effect has been improved.

Due to the special economic status of the Taihu Lake Basin, the Qing Dynasty also carried out frequent water conservancy construction here. According to statistics, in the 267 years since its founding, there were more than 2,000 constructions focusing on dredging rivers.It has repeatedly treated some major discharge channels in the Taihu Lake Basin, such as Wusong River, Huangpu River, Liuhe River, Baimao River, Mengdu River, etc., especially the Wusong River and Liuhe River, which have been dredged as many as 10 or 20 times.Some projects are also large in scale. For example, in the 10th year of Kangxi (1671 AD), the 23rd year of Jiaqing (1818 AD), and the 7th year of Daoguang (1827 AD), the Wusong River was dredged three times, all of which were 10,000 feet (150 feet long). more than one mile).These flood control projects in the Qing Dynasty had positive significance for alleviating flood and drought disasters in the Taihu Lake Basin.

The construction of rivers and lakes and other projects (including the transformation of natural rivers and lakes and the drilling of artificial rivers and lakes) has achieved remarkable results in preventing drought and general floods, and it has promoted the development of agriculture in the Taihu Lake Basin.However, the Taihu Basin is often hit by typhoons, among which the daily rainfall of strong typhoons can reach hundreds of millimeters.It will cause a catastrophic flood, and in the face of a catastrophic flood, these projects will appear weak.As far as Hepu is concerned, it is restricted by the dish-shaped topography of the Taihu Lake Basin, and its slope is extremely small, so it cannot quickly discharge the extremely large flood to the river and sea.As far as the lake is concerned, it is not like the strong and tall embankments built around the later large reservoirs, which are unable to accommodate a large amount of flood.Floods have a large amount of water and weak drainage and storage capacity, so it is inevitable to cause flood disasters.The ancients were very diligent in building farmland water conservancy in the Taihu Lake Basin, but floods still occurred frequently. It should be said that this is the main reason.

In modern times, people's ability to fight against nature has been greatly enhanced, and it is possible to completely conquer the floods and droughts in the Taihu Lake Basin.In order to turn the possibility into reality, after the establishment of the People's Republic of China, it started to implement such a comprehensive water conservancy construction plan in the Taihu Lake Basin.Its main content is to build seven large reservoirs in the upstream to effectively store the upstream flood. It can not only irrigate the local farmland, but also reduce the flood pressure in the middle and lower reaches; in the middle reaches, build a solid concrete embankment around Taihu Lake. It can greatly increase the water storage capacity of Taihu Lake, and on the other hand, it can prevent the flooding of Taihu Lake from flooding; in the downstream, in addition to dredging the old drainage channels, more than 10 new flood discharge channels must be drilled to improve flood discharge capacity; (Yangtze River, Qiantang River), build eight high-power electric pumping stations to quickly pump flood water into the river when it is flooded, and pump water from the river for internal irrigation when it is dry.Some of these planned projects have already been completed, and when they are all completed, the flood and drought disasters in the Taihu Lake Basin can be basically relieved.In terms of the most difficult flood disaster, it can be increased from the current once every three to five years to once every 50 years.After the completion of this plan, it will be able to solve the industrial water use and urban people's domestic water use in the region.It can also meet the needs of increasing water for the Jiangnan Canal after expansion.At that time, the Taihu Lake Basin will be the real paradise on earth.

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