In the Western Han Dynasty, the Longshou Canal was dug earlier, from the Yuan Shou to Dingyuan years of Emperor Wu of the Han Dynasty (BC122-1165438). At that time, a man named Zhuang Xiongbi wrote to the emperor, reflecting the demands of people in Linjin (now Dali), hoping to open a canal to divert Luoshui to irrigate more than 65,438+00,000 hectares of saline-alkali land east of Chongquan (now southeast of Pucheng). Emperor Wu of the Han Dynasty adopted this idea and sent more than 10,000 troops to undertake the task of digging canals. They set out from Zhengxian County (southwest of Chengcheng County), went to Nankai Canal and reached the foot of Shangyan Mountain (now Tielian Mountain). Because of the loose soil, the excavated ditch bank is easy to collapse, so they adopted a good channel structure. Well canal consists of underground passage and shaft. The former is a waterway, and the latter is convenient for people to go up and down, dig out and light up when digging canals. The deepest shaft is over 40 feet. Because many bone fossils were dug up when digging the canal and used as keels, it was called Longshou Canal. After the channel is dug, the effect of irrigation is not significant because the landslide problem cannot be solved. But it has created advanced water well and canal technology.
The Liu Fu Canal was built in the sixth year of Ding Yuan (BC 165438+ BC 0 1) and was presided over by Zuo Neshikuan. Small in scale, it is the floorboard of six auxiliary channels. Later generations thought that small water such as Ye Ye Valley, Qing Yu Valley and Zhuo Yu irrigated the farmland north of the upper reaches of Zheng Guoqu. These farmlands are located in higher ground, so they can't be irrigated in Zheng Guoqu. After the completion of the Liu Fu Canal, in order to better play the role of this project, according to "History of Han Dynasty Ni Kuanchuan", he also stipulated a "water order". This is the earliest recorded water system in China.
After the completion of the Liu Fu Canal 16 years, that is, the second year of Liang Wudi's reign (95 BC), the construction of the White Canal began. The project was proposed and presided over by Dr. Zhao Zhong and Dr. Bai Gong. The head of the canal is also at Gukou, which is in the south of Zheng Guoqu, flows southeast, passes through Chiyang (northwest of Jingyang County), Gaoling and Liyang (northeast of Lintong County), and flows into Weishui. It is 200 miles long and irrigates more than 4,500 hectares of farmland beyond Zheng Guoqu's reach. After the completion of Baiqu, Gukou, Chiyang and other counties became high-yield areas without knowing drought and flood due to irrigation by Zheng and Baiqu. At that time, such a folk song was popular in the local area, praising the role of the two canals:
Where is the field, Chiyang Gukou.
Zheng is in the front and Bai Qu is in the back.
Carry buckets for clouds and canals for rain.
There are several buckets of mud in a stone.
Irrigation and fertilization, planting my grain and millet.
Food and clothing, the capital, hundreds of millions of people. ("Records of Han Gou Jian")
Although the irrigated farmland area of Baiqu is much smaller than that of Zheng Guoqu, it is far more reasonable than that of Zheng Guoqu, so it is not easily blocked by sediment like Zheng Guoqu. Baiqu played a long role in history, which was developed in the Tang and Song Dynasties, while the downstream Qu Zheng was soon abolished. "There are stones in the water, and the mud is there." With high silt content, alkali can be pressed to fertilize the field, and the effect is really remarkable in a short time. However, we can't just see the advantages without seeing the disadvantages. In the long run, over time, it is easy to silte up canals and farmland, resulting in the field being higher than the canal and the canal being higher than the Jing, which is bound to destroy the whole irrigation system.
Another important irrigation and water conservancy project newly built in Guanzhong area during the Western Han Dynasty was the Guo Cheng Canal. When it was built and who was in charge of the project, there is no clear record in the history books, only that it was built during the period of Emperor Wu of the Han Dynasty. This is a large irrigation canal with weishui as its water source. It is located in the north of weishui, with the head of the canal in Shan county, adjacent to weishui in the east and passing through it. [Lili] (located in the southeast of Fufeng County today), Li Huai (located in the southeast of Xingping County today) and other counties, the end of the canal is connected with the Mengfu Canal in Shanglinyuan. The length of Guo Cheng Canal is slightly smaller than that of Baiqu Canal, and the irrigation area is about 1 10,000 hectares, which is more than double that of Baiqu Canal. Later, it once developed into the most important irrigation channel in Guanzhong. Shanglinyuan is located in the west of Xianyang, 300 miles a week, spanning the north and south of Wei River. It was an amusement place for emperors to shoot and hunt in Qin and Han Dynasties. Meng Er Canal is a waterway in the royal garden, which is used for watering the garden and boating.
In the long history, Guanzhong water conservancy has been composed of three major canal systems, namely, Jingjing canal system with water mirror as water source, Weihe canal system with Wei water source and Luoshui canal system with Luoshui water source. It can be said that these three canal systems were basically formed in the Western Han Dynasty.
In addition to the famous irrigation projects mentioned above, during the period of Emperor Wu of the Han Dynasty, a number of small irrigation canals were built south of Weishui, such as Lingbi [zhǐ paper] canal and? [Wei Wei] Canal, etc. They use the mountain stream originating in Nanshan as the water source to irrigate the farmland in Weinan.