Yijing Village, Dali County: Walk into Longshou Canal to divert Luogu Irrigation District and visit the site of Cave 5 in Luohui Canal.

In Yijing Village, Xuzhuang Town, Dali County, Weinan City, there is a section of the site of Longshouqu, which was built in the Western Han Dynasty. The culvert is 3,467 meters long and covers an area of about 2, square meters. During the Republic of China, when Luohui Canal was built, it crossed Tielian Mountain from here, which was basically consistent with the route of Longshou Canal in the Western Han Dynasty. On July 3, 218, this site of Longshouqu was listed as the fourth batch of provincial-level cultural relics protection units by the Shaanxi Provincial People's Government-

On December 8, 22, at the 71st Executive Council meeting of the International Irrigation and Drainage Committee held in Morocco, the Longshouqu Irrigation Area in Shaanxi Province was successfully selected as the world irrigation project heritage. From the third year of Yuanshou in the Western Han Dynasty (12 BC) to the sixth year of Yuanfeng (15 BC), Emperor Wu of the Han Dynasty adopted Zhuang Xiongbi's suggestion and built a canal here. Because of the discovery of the keel, it was named "Longshou Canal".

on the morning of September 13th, 221, under the leadership of the unit leaders, my colleagues and I went to Dali County to visit the landscape left over by the water conservancy project of Luohuiqu. First of all, we came to the east side of Yijing Village in Xuzhuang Town, and visited the Tibetan Silver Building and the water diversion gate here.

then, we walked about 3 meters north along the side of the middle trunk canal, and a newly-built Yijing water diversion hub appeared. The main trunk canal of Luohui Canal was divided into east trunk canal, middle trunk canal and west trunk canal. Today, it still plays the role of irrigation, and it has become the entrance to visit the Longshou Canal to divert Luogu irrigation area. On the wall next to it, there is a loud propaganda slogan: A thousand years of dragons flow in the ancient rhyme, and a hundred years of Luohui Runqin East.

Go through the Yijing water diversion hub, follow the main canal of Luohui Canal, and walk northward for about 1 meters. You can see a Yijing combined sluice. Here is the intersection of the main canal of the Yellow River irrigation area and the main canal of Luohui Canal, and water is replenished into Luohui Canal to realize the joint dispatch of water resources.

passing through the Yijing combined sluice, about 3 meters to the north, the main canal of Luohui Canal bifurcates, forming two channels towards the west and east. About 1 meters behind, two open channels extend into the culvert, forming a culvert crossing Tielian Mountain. Tielian Mountain is a loess tableland across the north of Dali County. Because the tableland looks like a sickle and a rainbow, it is commonly called Tielian Mountain or Changhong Ridge. This is an east-west multi-stage platform, which has been cut by running water for a long time, forming many gullies.

From 1934 to 1946, five tunnels were built in Tielian Mountain, and Li Yizhi, a water conservancy expert, named them Chengyuan Cave, Futian Cave, Dayou Cave, Chaochuan Cave and Pingzhi Cave from north to south, which meant to irrigate Chengcheng, Pucheng, Dali, Chaoyi and Cimin counties. Among them, the fifth tunnel is the last water conveyance tunnel of the main canal, which is called "five holes" for short. Later, in order to commemorate Zhang Pingzhi, an engineer who died in the line of duty, the cave was named "the cave of peace".

The water inlet of Pingzhi Cave is located in Yangquan ditch, 2m north of Miaodi New Village, Yongfeng Town, pucheng county, which is called "Wudongkou" by local people. The outlet of Pingzhi Cave is located at the south entrance of Yijing Village, Xuzhuang Town, Dali County, 1 meters west, which is divided into two entrances, east and west, and the distance between the two entrances is about 4 meters. In 1994, in order to increase the flow of water, a branch tunnel on the east side was excavated, with a total length of about 115 meters, named "Xinyuan Cave".

above the exit of Pingzhi Cave on the west side, you can see a long and narrow ravine, which is the remains of Longshou Canal in the Western Han Dynasty. On November 7, 1983, it was announced by Dali County People's Government as a county-level key cultural relics protection unit. Today, an old monument of key cultural relics protection units in Dali County is still erected here.

This site is the excavation relic from Yijing Village to Yuanzhi Village in Tielian Mountain of Longshou Canal, with a cross-section width of 5 to 1 meters, a depth of about 3 meters and a total length of about 1,6 meters. At that time, when the Luohui Canal was built, the herringbone Chinese cypress scaffold and the so-called "keel" fossils were found in the No.13, No.16 and No.18 working wells of this channel when the No.5 tunnel was excavated. Judging from this, it should be a part of the site of Longshou Canal in the Western Han Dynasty, which provides physical data for studying the historical changes of Longshou Canal and water conservancy construction in Weibei area.