Chapter 51 Section 5 New fish-scale stone ponds in the Qing Dynasty

During most of the Qing Dynasty, the main channel of the Qiantang River’s tidal surge was still facing the coastal areas of western Zhejiang such as Haining, Haiyan, and Pinghu, so this area was still the focus of the seawall project.In the early Qing Dynasty, it took more than half a century and cost 7-8 million taels of silver to transform most of the sea ponds here into the strongest new fish-scale stone ponds created by Zhu Shi. During the three generations of Kangxi, Yongzheng, and Qianlong, Zhu Shi successively held important positions such as governor of Zhejiang and minister of the Ministry of officials.During his tenure, he presided over the construction of seawalls in Jiangsu, Shanghai, Zhejiang and other places many times.In the fifty-ninth year of Kangxi (AD 1720), he integrated the advanced technologies of pond management in various aspects in the past, and built a 500-foot new fish-scale stone pond in the old salt warehouse in Haining.In July of the second year of Yongzheng (AD 1724), typhoons and high tides appeared in the north and south of the Qiantang River Estuary at the same time, causing a catastrophic tide disaster.At that time, except for the new fish-scale stone pond built by Zhu Shi in the old salt warehouse, most of the seawalls in the north and south of Hangzhou Bay were severely damaged, and the loss of life and property was very heavy.At first, due to the high construction cost of Zhu Shi's new fish-scale stone pond, 300 taels of silver were needed per zhang, so only 500 zhang were built without promotion.After the test of this spring tide, it was recognized as the "sample pond" of the seawall project.For the safety of western Zhejiang, the Qing government spared no effort to spend a lot of money and decided to rebuild the northern bank of the Qiantang River, which was most threatened by tidal surges, into new fish-scale stone ponds.

The new fish scale stone pond has the following characteristics: First, the foundation is more solid.In Huang Guangsheng's fish-scale stone pond in the Ming Dynasty, only the first half of the pond foundation was reinforced with piles after dredging, and the second half was left untreated.As for the pond foundation project of the new fish scale stone pond, in addition to dredging and laying piles in the front half, piles were also laid in the second half, so that the front and rear parts have the same pressure-bearing performance, and compound soil is used to tamp it.Second, the structure of the pond body is also tighter.The specifications of the stones are the same, five feet long, two feet wide, and one foot thick. .The bottom of the pond is 12 feet wide, generally built with 18 floors and 18 feet high, each layer shrinks inward, and the top is four and a half feet wide.Compared with Huangguang Shengshitang, although it is much smaller, its overall performance is better than it.Third, the pond protection project is also more particular. On the one hand, gravel and soil are built on the backside of the stone pond to enhance the tide-control performance of the pond body and prevent tidewater from infiltrating.On the other hand, Tanshui was built on the seaward side of the stone pond, and stones were used to build obliquely from the foot of the pond to the outside.The width of the tank ranges from 12 feet to 48 feet to protect the bottom of the pond and reduce tidal wave energy (Figure 19).

Due to the floods in the fifty-ninth year of Kangxi (AD 1720) and the second year of Yongzheng (AD 1724), the damage was widespread. In addition to the severe damage to the seawalls in western Zhejiang, the seawalls south of the Qiantang River Estuary and the south of the Yangtze River Estuary were also frequently damaged. destroy.Therefore, in addition to rebuilding the seawalls in western Zhejiang, the Qing Dynasty also built large-scale seawall projects in the south of the Qiantang River and the south of the Yangtze River.For example, in Shaoxing, Shangyu, Yuyao and other places in Zhejiang Province, more than 7,000 Zhang sea ponds were rebuilt; and the dilapidated earth ponds in Huating, Songjiang, Shanghai, Nanhui, Baoshan and other places in Jiangsu and Shanghai were successively rebuilt into stone ponds.The damage caused by tidal surges in these areas is smaller than that in western Zhejiang. Therefore, the stone ponds in these areas are mostly light stone ponds, and the cost is relatively low, about 50 taels of silver per foot.

In addition, on Chongming Island, the Qing Dynasty also started to build seawall projects.Chongming Island is the third largest island in my country today, covering an area of ​​more than 1,000 square kilometers.In the Tang Dynasty, it was still a small sandbar with an area of ​​only a dozen square kilometers. Due to the sediment deposition in the river and tide, it gradually developed into a large island in the Ming and Qing Dynasties.From the end of Ming Dynasty, in order to reclaim this new land, people began to build simple seawalls on the island.During the reign of Qianlong, an earth embankment with a certain scale was built, which was more than 100 miles long.During the reign of Emperor Guangxu, Liu Kunyi, governor of Liangjiang, built a stone embankment on it.

The Qing Dynasty also made some new explorations in preventing tide surge disasters.One is to try to make the owner of the Qiantang River tide slip through the middle and small gates.Because the main tide surger slips away from the north gate and the south gate, it is easy to cause serious tide disasters, especially if you walk through the north gate, the disaster is more serious. Only when you walk through the middle and small gates, the tide disaster is less.Therefore, during Qianlong's reign, he organized forces to dredge the middle and small gate waterways to attract tides to pass through, and achieved certain results.This is a very meaningful exploration.The second is that when the seawall was built in the late Qing Dynasty, it tried to use the new building material cement in the project.Although this experiment failed due to the subsidence of the foundation at that time, it provided lessons for people.During the period of the Republic of China, the use of cement as a material for pond construction gradually increased, and some achievements were made (Figure 20).

For thousands of years, the development of seawall projects in Jiangsu, Shanghai, and Zhejiang reflects the perseverance and ingenuity of the local people in fighting against tidal disasters.The construction of the seawall is a strong guarantee for the personal safety of the people and the local industrial and agricultural production.