What was the important irrigation and water conservancy project built in Guanzhong area during the Western Han Dynasty?

Guo Cheng Canal is an important irrigation and water conservancy project newly built in Guanzhong area during the Western Han Dynasty. 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 Weihe River as its water source. It is located in the north of Weishui, with its head in the county seat, bordering Weishui in the east, passing through Gedi (now southeast of Fufeng County), Li Huai (now southeast of Xingping County) and other counties, and its tail is connected with Mengfu Canal in Linyuan. 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.