If you were the commentator of the scenic spot, how would you introduce Dujiangyan?

Dujiangyan is located in the west of Dujiangyan City, Sichuan Province, on the Minjiang River in the west of the Chengdu Plain. The Dujiangyan Water Conservancy Project was built in 256 BC. It is the oldest and only remaining grand water conservancy project in the world that is characterized by diversion of water without dams. It is a national key cultural relic protection unit. The scenery near Dujiangyan is beautiful and there are many cultural relics and historic sites, including Fulong Temple, Erwang Temple, Anlan Cable Bridge, Yulei Pass, Lidui Park, Yulei Mountain Park and Lingyan Temple.

The Dujiangyan Water Conservancy Project consists of three main projects: the Yuzui Diversion Dike, the Feishayan Spillway, and the Baopingkou Water Diversion Entrance when it was founded, as well as ancillary projects such as the Baizhang Dike and the Herringbone Dike. Scientifically solved the problems of automatic diversion of river water, automatic sand discharge, and control of incoming water flow, eliminating floods and turning the western Sichuan plain into a "land of abundance" where "floods and droughts follow people". For more than two thousand years, it has been playing a role in flood control and irrigation. As of 1998, the irrigation scope of Dujiangyan has reached more than 40 counties, with the irrigated area reaching 668,700 hectares.

Yuzui is a water diversion dam built in the middle of the river. It divides the turbulent Minjiang River into an outer river and an inner river. The outer river drains floods and the inner river diverts water for irrigation. Feishayan plays the role of reducing floods, discharging sand and regulating water volume. The mouth of the treasure bottle controls the flow of water. Because the shape of the mouth is like the neck of a bottle, it is called the mouth of the treasure bottle. The water from the Neijiang River flows into the western Sichuan plain through Baopingkou to irrigate farmland. The part of the hill cut off from Yulei Mountain is called "Lidui".

The Dujiangyan Water Conservancy Project makes full use of the local geographical conditions of high in the northwest and low in the southeast. According to the special terrain, water veins, and water potential at the mouth of the river, it takes advantage of the situation to divert water without dams and implement gravity irrigation, so that embankments and distribution systems can be used. Water, flood discharge, sediment discharge, and flow control are interdependent and form a system to ensure that the comprehensive benefits of flood control, irrigation, water transportation, and social water use are fully exerted. After the completion of the Dujiangyan Irrigation System, the Chengdu Plain was fertile and wild for thousands of miles. "Waters and droughts follow people, and they don't know about famine. There is no shortage of years. It is called Tianfu." Sichuan's economy and culture have developed greatly. The greatest thing about it is that the weir has endured for more than two thousand years and is playing an increasingly important role. The establishment of Dujiangyan is based on the premise of not destroying natural resources and making full use of natural resources to serve mankind, turning harm into benefit and achieving a high degree of coordination and unity among people, land and water.

The Dujiangyan Irrigation Project still exists today and is still functioning. With the development of science and technology and the expansion of the irrigation area, starting from 1936, concrete mortar cobblestone technology was gradually used to repair and strengthen the canal head project, and some water conservancy facilities, the engineering layout of the ancient weir and the "deep beach" were added. The water control strategies such as "lowering weirs", "taking advantage of the situation and adjusting measures to the times", and "cutting off corners when encountering bays and pumping out water when times are right" have not changed. The Dujiangyan Irrigation Project has become a model for the best water resources utilization in the world. After carefully watching the design of the entire project, water conservancy experts were amazed at its high scientific level. For example, the design of Feishayan makes good use of the theory of swirling flow. This weir can divert water for irrigation in normal times, and can drain water into the outer river during floods. It also has the function of discharging sand and gravel. Sometimes large stones can roll away from the weir. There was no cement at that time, so for such a large project, local materials were used. Bamboo cages were used to install pebbles as weirs, which was cheaper and more effective.

The area around Dujiangyan has beautiful scenery and many places of interest, making it an ideal tourist destination. There are places of interest such as Erwang Temple, Fulong Temple, and Anlan Cable Bridge in the Dujiangyan area.

The Erwang Temple is located on the hillside on the right bank of the Minjiang River, in front of Dujiangyan. It was originally a temple to commemorate the King of Shu. During the Jianwu period of Qi Dynasty (494-498 AD), it was renamed "Chongde Temple" to commemorate Li Bing and his son. temple". After the Song Dynasty (960-1279 AD), Li Bing and his son were successively named kings by the emperor, so later generations called it the "Two Kings Temple". The main hall of the temple enshrines statues of Li Bing and his son respectively, and also collects famous quotes on water control, poet inscriptions, etc.

Fulong Temple is located in Lidui Park. Legend has it that Li Bing subdued the evil dragon here when he was controlling floods. There are now three levels of the temple. In the center of the front hall is a stone statue of Li Bing carved during the Eastern Han Dynasty (25-220 AD). There are also stone statues of weir workers in the Eastern Han Dynasty and the Flying Dragon Cauldron, a relic of Jinxian and Princess Yuzhen from the Tang Dynasty when they practiced Taoism in Qingcheng Mountain.

Anlan Cable Bridge is also known as "Anlan Bridge" and "Couple Bridge". It was built before the Song Dynasty. Located above the fish mouth of Dujiangyan, it is known as the "Five Great Bridges in Ancient China" and is the most distinctive landscape of Dujiangyan. The cable bridge is supported by wooden rows of stone piers, and thick bamboo cables are used to hang across the river. Wooden boards are laid on top as the bridge deck, and bamboo ropes are used as railings on both sides. The total length is about 500 meters. It was destroyed by war in the late Ming Dynasty (17th century AD). The current bridge is made of steel cable concrete piles.

Dujiangyan is not only a world-famous ancient Chinese water conservancy project, but also a famous scenic spot. In 1982, Dujiangyan, as an important part of the Qingcheng Mountain-Dujiangyan Scenic Area in Sichuan, was approved by the State Council to be included in the first batch of national scenic areas. On May 8, 2007, Chengdu Qingcheng Mountain-Dujiangyan tourist attraction was officially approved by the National Tourism Administration as a national 5A-level tourist attraction.

According to the definition of cultural heritage in Article 1, paragraph 2, of the United Nations Convention for the Protection of the World Cultural and Natural Heritage: “Buildings: Buildings: architectural style, uniform distribution or A single or connected building group that has outstanding universal significance value in combination with the environmental scenery."

Dujiangyan Water Conservancy Project has a long history, large scale, reasonable layout, scientific operation, and harmonious integration with the environment. It has outstanding universal value in history and science. In 2000, Dujiangyan was designated as a world cultural heritage at the 24th session of the United Nations World Heritage Committee. .