The historical evolution of Dujiangyan Fish Mouth

Dujiangyan Irrigation System lies on the Minjiang River in the northwest of Dujiangyan City Sichuan China. It was built over 2,200 years ago around 250 B.C. under the direction of LiBing, the governor of the Shu Prefecture of the Qin State. Construction of the Dujiangyan irrigation system began in the 3rd century B.C. This system still controls the waters of the Minjiang River and distributes it to the fertile farmland of the Chengdu plains. Since the hydraulic headwork of ancient Dujiangyan were mainly composed of three main components, namely: Fish Mouth, Flying Sand Sluice and Baopingkou. This paper emphatically summaries the evolution of Fish Mouth´s position and construction material in its over 2200 years from 250 B. C. to present.