Dujiang Yan
都江堰
Dujiang Yan(The Dujiang River Dyke ) is a great ancient irrigation project situated about 50 kilometers northwest of Dujiang Yan City，Sichuan Province.
都江堰是一项伟大的古代水利工程，位于四川省成都市西北方向约50千米处的都江堰市。
The Minjiang River is a major tributary of the Yangtze River in its upper rea-ches.Before Dujiang Yan was built, when torrential water rushed down the mountains in summer, the Minjiang River overflowed its banks and caused serious floods on the Cheng Du Plain. When the rainfall was not plentiful，the flow of water in the Minjiang River would decrease，aggravating the drought on the western Si-chuan Plain.
眠江是长江上游的一条较大的支流，发源于四川省北部高山地区。在都江堰建成以前，每当春夏山洪暴发之时，江水奔腾而下，由于河道狭窄，常常引起洪灾，洪水一退，又是沙石千里，造成东旱西涝。
In 256BC，Li Bing was appointed governor of Sichuan. To conquer the floods of the Minjiang River, he trekked upstream until he reached the area of the present-day Aba Tibetan Autonomous Prefecture. He got a lot of hydrological data on the Minjiang River. Then he began to build Dujiang Yan. Dujiang Yan system consists of the Fish Mouth，the Sand-flying Dyke and the Precious Bottle Neck.
秦昭襄王五十一年(公元前256年)，秦国蜀郡太守李冰沿崛江逆流而上，艰苦跋涉，亲自勘察崛江的水情、地势等情况，直至今日的西藏自治区的阿坝。他吸取前人的治水经验，率领当地人民，主持修建了著名的都江堰水利工程。都江堰的主体工程包括鱼嘴分水堤、飞沙堰溢洪道和宝瓶口进水口。
The Fish Mouth is a diversion dam built of pebbles. It divides the Minjiang River into the inner river and the outer river. The water of the inner river flows through the Precious Bottle Neck to irrigate 200，000 hectares of farmland around Cheng Du.The outer river was designed mainly to release floodwater. The Sand-flying Dyke between the Fish Mouth and the Precious Bottle Neck is an overflow dyke. When there is too much water in the inner river, the surplus water brims over the Sand-flying Dyke and flows into the outer river.
鱼嘴分水堤由鹅卵石修建而成，作用是将眠江水流分成内江和外江，其中内江水流经宝瓶口进水口引人成都平原，灌溉面积达20万公顷，而外江水流则将洪水引人内江水流，剩余的水经位处内江和外江之间的飞沙堰溢洪道溢出至外江水流。这样既可以分洪减灾，又可以引水灌田、变害为利。
After Dujiang Yan was completed，Li Bing composed the rhyme easy for mem-ory:“Dredge the riverbed when the water is deep and build low dykes when the water is low.”It contains the guiding principle of dredging the waterways in ancient China.
为了观测和控制内江水量，李冰又雕刻了三个石桩人像，放于水中，以“枯水不淹足，洪水不过肩”来确定水位。他还凿制石马置于江心，以此作为每年最小水量时淘滩的标准。
Dujiang Yan serves the purposes of navigation，flood control，log floating and urban water supply. The trinity of the Fish Mouth，the Sand-flying Dyke and the Pre-cious Bottle Neck keeps an effective control of water flowing into the inner river. In case of drought，Dujiang Yan channels water into the fields. If waterlogging oc-curs，the floodwater can be diverted.With the completion of Dujiang Yan，both floods and droughts have been brought under control and famine years have gone.The Cheng Du Plain becomes“a land of abundanc”，with an irrigation area of 10 million mu(1 mu=1 / 15 hectare ).
都江堰一直发挥着航行、防洪、运木、供水等作用，它的三大部分，鱼嘴分水堤、飞沙堰溢洪道和宝瓶口进水口，有效地解决了江水自动分流、自动排沙、控制进水流量等问题，消除了水患。都江堰工程使成都平原从此沃野千里的天府之国。目前灌溉面积超过1000万亩。
Dujiang Yan has been in use for more than 2000 years. It is a miracle in the world history of water conservancy.
2000多年来，都江堰一直发挥巨大效益。它是世界水利工程的奇迹。