From Yuan Shuo to Yuan Qiu (120 BC ~ 111 BC), a man named Zhuang Xiongyu wrote to the emperor and suggested that the canal should be channeled into Luoshui irrigation fields. He said that the people in Linjin are willing to dig a channel of water from Luoshui to irrigate the land east of Chongquan. If the channel is completed, more than 10,000 hectares of saline-alkali land can be irrigated and the benefits of ten stones per mu can be received. Emperor Wudi accepted this suggestion, soliciting more than 10,000 people to open a canal.
Introducing Luoshui Water to irrigate the Linjin Plain, you must open a canal in Zhengxian County upstream of Linjin. However, between Linjin and Zhengxian, there was a long and narrow Shangyan Mountain (now Tiexian Mountain). The channel passed through Shangyan Mountain, which brought great difficulties to the construction.
In the original channel excavation, the method of cut through the mountain was adopted, but because the mountain was more than forty feet high, it was all covered by loess. When excavating a deep canal, it was easy to collapse. The channel must pass through Shangyan Mountain for more than ten miles. If it is excavated from opposite ends only, there will be fewer construction surfaces, ventilation in the cave, and lighting difficulties. If several more shafts are drilled in the middle of the canal line, this will not only increase the construction work surface, but also speed up the construction progress, and also improve the ventilation and lighting conditions in the tunnel.
Then, the workers at the time invented the ditch method. The so-called well canal method means that on the slope of the tunnel line, a vertical shaft is drilled every 300 meters, so that the Longshou canal passes through the seven-mile-wide Shangyan Mountain from the ground, creating a precedent for the later tunnel construction method.
The Longshan Shoal Crossing Tunnel is the most famous hydraulic tunnel in ancient China. The well channel method is undoubtedly a new creation of the tunnel construction method. At the same time, the construction of Longshou Canal also demonstrates the high level of surveying technology . It is invaluable to accurately determine the azimuth of the canal line and the position of the vertical shaft without seeing at both ends. During the construction of Longshou Canal, people have excavated fossils of dinosaurs, so this channel is called Longshou Canal.
The completion of the Menglong Shouqu has enabled more than 40,000 hectares of saline-alkali land to be irrigated and turned it into a first-class field of ten acres per mu, which has increased its output by more than 10 times. This section of the Underground channel that passes through Shangyan Mountain is more than 5 kilometers long. It is the first underground channel in Chinese history and a great creation in the history of water conservancy in the world.
The Jingjing Canal Method was transmitted to the Western Regions through the Silk Road at that time. Until today, Xinjiang people still use this combination of canals and canals to build irrigation channels in desert areas, called Kaner Wells. This method is also used to irrigate farmland in arid regions of Central and Southwest Asia. The canal method of the Longshou Canal in the Western Han Dynasty was the crystallization of the highly intelligent working people in ancient China, and provided valuable experience for the world s water conservancy cause.
Alas, Jiang Shidu, a well-known water conservancy family, rebuilt an irrigation project in this area. Jiang Shidu not only introduced Luo River, but also introduced the Yellow River water for irrigation, and the benefits were even more significant. Since then, the irrigation regime of Yinluo has continued. After liberation, Luohui Canal further expanded, and the irrigated area increased to more than 600,000 mu.