History of Tang Laiqu

By the Tang Dynasty, the old canals of the Han Dynasty had been fully renovated and newly built and expanded. The famous ones include Han Canal, Qi Level, Guanglu, Shangshu, Yushi, Bogulu, Hu Can, and Baijia Canal. , Te Jin and other channels.

The large-scale development of the Tanglai Canal Irrigation Area and the transfer of Huaiyuan County (today's Yinchuan) from the front edge of the terraces west of the Yellow River to the Tanglai Canal bank in the center of the terraces marked the transformation of the irrigation area into low-lying terrain, dense lakes and swamps, and the original saline soil The development of the central part of the plain shows that the productivity level in the Tang Dynasty increased to a new stage.

According to official history, the Yinchuan Plain was rich in rice during the Song Dynasty.

The author believes that at least in the Tang Dynasty, large-scale rice cultivation should have been developed here [8].

Because the main part of the Tanglai Canal Irrigation Area is the heavily swampy area in the middle of the plain, people have to use the methods of digging ditches for drainage and planting rice to wash out salt (this method has been around since before the Later Han Dynasty). It has been adopted by many areas in the Yellow River Basin).

The agricultural proverb "digging ditches and planting rice on alkaline soil" has been passed down from generation to generation by farmers in the Yinchuan Plain. It is a summary of the production experience of past generations.

It is said that Guo Yuanzhen was working in the fields in Hexi, making full use of water and land, and the rice harvest was bumper.

During the reign of Emperor Xuanzong, he was stationed in Lingzhou, so he must pay attention to promoting rice cultivation.

It goes without saying that since then, some lakes and swamps in the Yinchuan Plain have been destroyed at an accelerated pace due to human intervention and have gradually turned into paddy fields.

As rice fields expand and water diversion increases, residual irrigation water may gather into new lakes and swamps in the downstream depressions.

After the Ming and Qing Dynasties, the plain irrigation area expanded on a large scale. Especially in the Kangxi and Yongzheng dynasties in the early Qing Dynasty, the Daqing, Huinong, Changrun and other canals were built, and the irrigation area increased from the original 1.7 million acres. The area jumped to 2.4 million acres, but drainage facilities were not built accordingly. The problem of unbalanced irrigation and drainage suddenly became very prominent, causing a large number of depressions between canals to accumulate water and form lakes.

In the Yinchuan Plain Yellow River Diversion Irrigation Area, a multi-head canal system was gradually formed under the conditions of ancient dam-less water diversion. The main canals were arranged parallel to the Yellow River, dividing the land in the irrigation area into long strips in the north and south, resulting in the direct opening of the main canals. The mouths of fighting canals and agricultural canals are often prone to bursting during irrigation.

In the Yinchuan area, due to channel obstruction, except for the easternmost Huinong Canal, no other main canal can safely withdraw water into the river. When the river water rises or there is heavy rain, the canal water can only be discharged to people. Lakes and ditches, this has resulted in the historical situation of chaotic ditches, water accumulation in depressions, and dense lakes and swamps in the middle and lower reaches of the Yinchuan Plain.

Generally speaking, the banks of the channel are higher-lying farming areas. Obviously, the higher terrain on both sides of the channel is caused by the yearly accumulation of sediment caused by irrigation, channel breaches, etc.; between the two channels is the lake and depression area. , recurring regularly from west to east.

This kind of lake is a secondary lake that appeared with the development of irrigation areas. It began in the Han and Tang Dynasties and reached its peak after the early Qing Dynasty. It can be called a depression lake between canals.

During the Qianlong period of the Qing Dynasty, there were 48 famous larger lakes such as Chang Lake and Yue Lake near Fucheng (now Yinchuan) in Ningxia alone. There were 72 connected lakes in the east and west of the river.

The one between the two forts of Shaogang and Li Jun is the largest, with a circumference of dozens of miles. There are no weeds, but the water is deep and full of fish. It is clear and green, with reflections of the mountain light. There are trees in the distance, and there are boats coming and going from time to time. In the mist, those who passed by made me think of Jiangxiang."

In the feudal society, when water conservancy was not repaired, when there were heavy rains, flash floods, flooding of the Yellow River, or channel breaches, "the water would often flow across the land, soaking the long acres, and there would be wild borers and few seedlings." Lakes, swamps, and fields would be destroyed. The land merged into a vast ocean.

It can be seen from the "Overview of Canal Flows in Ningxia Province" and "Tanglai Canal Basin Map" surveyed and mapped in 1935 that almost the tail end of most branch canals are lakes and swamps.

The water surface in the area near Yinchuan actually accounts for about 1/4 of the total area.

"The remaining water from all the branch canals in the east of the river has nowhere to drain, so it all flows back to the lower area between the Qin and Han canals, forming a lake-beach connection and a vast ocean." It is a famous large lake beach. There are more than 20 lakes such as Balang Lake. The larger one has a circumference of more than 10 kilometers, and the smaller one has a circumference of about one or two kilometers.

The result is widespread swampiness and salinization in the inter-channel areas, which affects stable and high agricultural yields.

Therefore, although the central part of the Yinchuan Plain has been developed in the Tang Dynasty, the average grain yield has remained at a level of tens of kilograms for a long time.

In the low-lying areas of the Yinchuan Plain, there are also water-filled depressions and lakes formed after major earthquakes. The most prominent examples are Mancheng and Baofengcheng in Ningxia.

Ningxia Mancheng is a castle built in the first year of Yongzheng in the early Qing Dynasty (1723) to station Manchu banner soldiers. It is located 2.5 kilometers northeast of Ningxia Fucheng.

The city is located in a low-lying area, and every rainy season there is muddy water.

After the earthquake in the third year of Qianlong's reign (1739), all the houses collapsed, the city walls sank, and the terrain became more depressed, forming a stagnant swamp. It was impossible to rebuild the city, so the city had to be moved to a site 7.5 kilometers west of Fucheng (today's Yinchuan New Town).

Most of the former sites of Mancheng (where Manchun Township is located on the outskirts of Yinchuan City today) have become fish ponds and rice fields.

Baofeng County, newly established during the Yongzheng period, was also devastated by the earthquake and the ground sank. “After the earthquake, large caves opened up, water swirled out, and rivers overflowed. The city was a vast expanse of water, ranging from four to five feet to six or seven feet deep. Many people and livestock froze to death, and every military weapon and other items were completely submerged."

Since then, Baofeng County has been abolished. In 1981, during an inspection of Baofeng City (where Baofeng Township in Pingluo County is located), large swamps and water-filled depressions were still found inside and outside, and residents only lived in a corner of the south city.

In addition to freshwater lakes, primary and secondary salt ponds have existed on the Yinchuan Plain since ancient times.

According to records, Huaiyuan County (the Yinchuan area was Huaiyuan County and Huaiyuan Town in the Tang and Song Dynasties) “has three salt ponds... The Red Peach Salt Pond is like peach blossoms and is located 320 miles west of the county; the Wuping Salt Pond It is 12 miles northwest of the county, and the Hechi Salt Pond is 145 miles northeast of the county." Among them, the Wuping Salt Pond must be within the Yinchuan Plain.

Down to the Ming Dynasty, there were still salt ponds 15 kilometers north and south of Ningxia Fucheng. The production was not large, and officials could not help it. It was estimated to be a mixture of chloride and sulfate.

Until the founding of the People's Republic of China, there were still activities of collecting nitrate salt near the North Tower of Yinchuan City.

As we all know, all lakes and swamps on the Yinchuan Plain that are not directly connected to rivers and channels have been salted to varying degrees and become brackish water lakes, salt water lakes or even salt lakes.

After the founding of New China, due to the construction of a relatively complete drainage ditch system, many shallow lakes and water-filled depressions were drained, and the lake area dropped from about 790,000 acres before to about 240,000 acres in 1958. , in 1981 there were only 160,000 acres left.

The water depth of existing lakes has also been greatly reduced.

In addition, the area of ??seasonal waterlogged depressions has decreased more than in the past, and the geographical landscape of the Yinchuan Plain has undergone tremendous changes.

The complex process of shrinking-expanding-shrinking that plain lakes and swamps have experienced in geological periods and human history has been affected by various natural factors such as land subsidence, sedimentation, flooding of the Yellow River, and climate drying. influence of factors.

Since the development of the Yellow River Irrigation Area in the Han Dynasty, the changes in lakes and swamps have been closely related to the development activities of the irrigation areas at different stages, while various natural factors have played a relatively secondary role.

Changes in the area of ??lakes and swamps, especially lakes and swamps between canals, and the salinization or desalination of water bodies can be said to basically reflect the status of irrigation and drainage balance and water-salt balance in irrigation areas in different periods.