Name
In the early days of li bing's construction, tujiang was named “sang” because the yuji shan by tujiang used to be known as “sang” and the main people living around tujiang were “sang” who called it “sang” and thus “sang” by dujiang。
During the tri-hands, tuan district was set up in the dujiang district, which, in view of its name, is known as “dou xian”. At the same time, it is also known as the “golden embankment”, which highlights the role of the fish mouths in dividing water embankments, named after them。
Tang dynasty, dujiang has been renamed the "sniptail." for the materials and techniques used at the time to build the embankment consisted mainly of “tangled bamboo, three feet in diameter, water in stone, and water in water”, i. E., the pegged mackerel, known as “tangular tail”。
It was not until song dynasty, in song story, that for the first time it was mentioned that tujiang: “at the age of the yongkang army, to overcome the river, the cages of stones and snakes were strewn with water to fill the county fields.”
With regard to the source of the name tokujiang, the sengdu river, a chengdu river with two origins, the yangjiang river and the river, says. The river is another name for chongjiang, the capital river on the chengdu plain, and the south river, the river of chongjiang, which is upstream, the river of palai and the river of ma. “the dujiang is the chengdu river” says. Starting with song, the project to summarize the entire tujiang system, known as dujiang, has more accurately represented the entire system of hydroelectric engineering, which has continued to date。
Build background
The chengdu plain, known as the “state of the sky”, was an ancient site of severe water and drought. Lee baek's exasperation and tragedy in the famous poem "smuggles and fish." this situation is due to the natural “bad” conditions of the kanjiang and chengdu plains。
The yangtze river is a major tributary upstream of the yangtze river, and the western sichuan basin, which runs through, is a heavily rained area of china. From sichuan and gansu's border, the south is divided into east and west, east and west, from the bows and west. The two sources co-exist in the non-dambling of zorra in songpan. To the south, the city of songpan, the city of dujiang, and the city of leshan are moving to yangtze in ibein. The total length is 793 kilometres and the basin covers an area of 133,500 square kilometres. The average slope is 4. 83 per cent, with an annual average of about 15 billion m3. The river is 3560m, with more than 13 million kilowatts of hydro resources。
The yangtze river is the largest tributary of water in the yangtze river, with more than tujiang upstream, dominated by driftwood and hydro-power generation; the city of tujiang to le shan, midstream, passing through the chengdu plain area, which together with its water system and numerous artificial river networks, forms the dujiang irrigation area; and downstream, with shipping as its main route. It has more than 90 tributaries, large and small, and upwards black-water, groan-brained rivers; in midstream, black-stone, kimma, river an, ma, blank, buyang rivers, etc. In the tujiang irrigation area; and downstream, green-clothed, cross-bread, maby river, river across-brook, etc. The main source of water is from the right bank, which is in a difficult terrain, and the large tributaries, which are spilling over from the right bank's hill, mainly during the rainy season, so that the water of the river is rising rapidly and in a state of emergency。
The yangtze river runs southwards from the western side of the chengdu plain, where the whole of the chengdu plain lies on the surface of the tunnel and hangs very heavily. The entire terrain of the chengdu plain is from the yangtze river, which is tilted south-east, with a large slope of 50 km and a gap of 273 m. In ancient times, the plains of chengdu were a vast ocean when the river was flooded; in the event of a drought, the ground was red and the particles were lost. The long-standing scourge of the river and the destruction of the land by the whales is a major obstacle to the survival and development of the ancient nation。
The creation of dujiang has its specific historical roots. At the time of the war, the swords and swords rose, the war was raging, and the people who had suffered from it were eager for china's reunification as soon as possible. It is a coincidence that the qin nation, which has been reformed through commercial transformations, came out with a great deal of power. They rightly recognized the special strategic position of palestine in the process of reunification of china, “the best of all and the best of all”. In this historic context, the late king qin of the war state appointed li bing, who knows the astronomical, geography and invisibility, to be the master of the county. Upon taking office, li bing resolved first to address the drought in the yangtze river, develop sawashi agriculture for the benefit of chengdu plain and create an economic base for the reunification of china。
Construction of the environment
Dujiang project map
The dujiang river is located in the area where the river can enter the alluvial plains from the valleys, irritating thousands of agricultural land on the chengdu plain east of the irrigation county. Turning out to pass through the steep slopes of the river, water slowed suddenly as soon as it reached the plains, and a large number of sands and rocks were deposited and silted the river。
Each year, when the rainy season comes, the river and other tributaries surge and tend to flood; when rain is insufficient, it causes drought. Two or three hundred years before the dujiang river was completed, king duyu of gujong city opened a man-made river in the mountains of the yangtze river, divided between them into the yangtze river in order to remove the water。
