(1) Phase I Project: Bottle Mouth
Note: The main purpose of building Baokoukou is to introduce Minjiang River into Chengdu Plain for flood control and disaster reduction.
(II) Phase II Project: Fish Mouth
Note: After the completion of Baokou Port, although it played the role of water diversion and irrigation to a certain extent, it alleviated the drought in Chengdu Plain to a certain extent. However, because it is difficult for the high rivers in the east to flow into Baokou Port, the second phase of the project was started.
(iii) Phase III project: flying sand weir
Note: After the construction of Yu Zui Project, some sediment problems in dry season and wet season were solved, but the wet season may cause excessive runoff and sediment deposition in Neijiang, so the flying sand weir was built. The weir and the dike have the same point of retaining water, but the difference is that the dike must ensure that the water flow cannot overflow; Weir is to block the water and let it overflow.
Extended data
In 256 BC, during the Warring States Period, Li Bing, the prefect of Shu County of Qin State, led a crowd to build Dujiangyan Water Conservancy Project, which was located in Sichuan. On the Minjiang River in the west of Dujiangyan City in the west of Chengdu Plain, 56 kilometers away from Chengdu. Large-scale water conservancy projects are still irrigating farmland, which is a great water conservancy project that benefits the people. It is characterized by long time and no dam to divert water, and it is the originator of world water conservancy culture. This project mainly consists of Yuzui diversion dike, Sha Fei weir spillway, Baokou intake, Baizhang dike, herringbone dike and other ancillary works. Scientifically solved the problems of automatic diversion (fishmouth diversion dike divides water into four or six parts), automatic sediment discharge (fishmouth diversion dike divides sand into two or eight parts) and control of incoming water (Baokou and Sha Fei weir), thus eliminating floods. 198 The irrigated area reached 668,700 hectares, and the irrigated area has reached more than 40 counties. In memory of Li Bing and his son, people built a temple of Li Bing and his son, called Erwang Temple.
References:
Baidu encyclopedia-Dujiangyan water conservancy project