The Three Gorges of the Yangtze River

The Three Gorges of the Yangtze River

The Three Gorges of the Yangtze River starts from Baidi City, Fengjie County, Chongqing City in the West and ends at nanjinguan, Yichang City, Hubei Province in the East, with a total length of 193km. Along the way, there are steep peaks and steep cliffs on both sides of the river. From west to East, there are Qutang gorge, Wuxia gorge and Xiling Gorge.

In Wushan County of Chongqing, there are the small Three Gorges of Daning River and Madu river. Along the Yangtze River, in Chongqing, there are Baiheliang, the "forest of underwater steles", Fengdu ghost town, the "land of Oriental Divine Comedy", Shibao village with peculiar architectural style, zhangfei temple, Tuogu Hall of Liu Bei, the emperor of Shu Han Dynasty, and Wushan cultural site in Longgupo.

"Three Gorges of the Yangtze River" is one of the top ten cultural symbols in Chongqing

"The Three Gorges of the Yangtze River --- Kuimen" is the fifth set of landscape patterns on the back of RMB 10 notes.

On February 19, 2018, the south line ship lock of the Three Gorges project was put into operation for 33 days until 8:00 on March 24. The north line ship lock of the Three Gorges Project will adopt the mode of one-way passing and timing reversing.

Construction history

In 1918, Sun Yat Sen put forward the original idea of establishing the Three Gorges Project in his article "the general plan for the founding of the people's Republic of China": "when the water of the Three Gorges project is weired by the sluice, the boat can flow upstream, and its water power can be used."

After the founding of the people's Republic of China, the Yangtze River Water Conservancy Commission was established in February 1950 to carry out comprehensive management of the Yangtze River.

In 1955, the planning of the Yangtze River Basin and the survey, scientific research and planning of the Three Gorges Project began to be carried out in an all-round way, and they were basically completed by the end of 1957.

On December 26, 1970, the construction of the Gezhouba Project on the Yangtze River was approved. This is a planned and step-by-step preparation for the construction of the Three Gorges Project.

On April 3, 1992, the fifth session of the Seventh National People's Congress passed the "resolution on the construction of the Three Gorges Project", which completed the legislative process of the Three Gorges Project and entered the implementation stage.

On September 27, 1993, China Three Gorges Project Development Corporation was officially established in Yichang city.

On December 14, 1994, Premier Li Peng of the State Council announced to the world that the Three Gorges project was officially started in Sandouping, Yichang.

On November 8, 1997, the Three Gorges project successfully achieved the river closure, and the first stage construction target was completed.

In 1998, the Three Gorges project entered the second stage of construction.

In 2000, the installation of Three Gorges project units played a prelude.

On October 10, 2002, the expert group meeting of the Acceptance Committee of the second phase of the Three Gorges Project of the State Council was held in the dam area, and the acceptance work before the closure of the diversion channel was officially launched.

On October 21, 2002, the most critical flood discharge dam section of the Three Gorges dam was completed, reaching the design elevation of 185m above sea level.

On October 25, 2002, the State Council held a plenary meeting of the Acceptance Committee of the second phase of the Three Gorges project, and agreed with the opinions of the acceptance group of the pivotal project on the implementation of the diversion channel closure in November 2002.

On October 26, 2002, the dam on the left bank of the Three Gorges project with a total length of 1.6 km was capped, and the whole dam section has been raised to the design crest elevation of 185m above sea level.

On October 29, 2002, Premier Zhu Rongji presided over the 11th meeting of the Three Gorges Project Construction Committee of the State Council, agreed with the opinions of the Three Gorges Project Acceptance Committee of the State Council, and decided to close the diversion channel on November 6.

On November 7, 2002, the rotor of the world's largest hydro generator set was successfully hoisted at the Three Gorges construction site, marking the completion of the installation of the first unit in the Three Gorges Project and the beginning of the general assembly stage.

On December 16, 2002, the third phase RCC Cofferdam of the Three Gorges project started pouring. The total design pouring volume of the third stage cofferdam is 1.1 million cubic meters. It will protect the construction of the right bank dam, the power plant and the right bank non overflow dam section together with the downstream earth rock cofferdam. It is a key project to realize the water storage, navigation and power generation of the third stage project.

On April 11, 2003, the navigation of the temporary ship lock of the Three Gorges project was stopped, and the navigation of the Three Gorges water area was suspended for 67 days, and the navigation was resumed on June 16. At the same time, the work of dam overturning and transfer was started in an all-round way.

On April 16, 2003, the RCC Cofferdam of the third phase of the Three Gorges project reached the top, 55 days ahead of the contract period, reaching the design elevation of 140m.

On April 22, 2003, the project of rebuilding the temporary ship lock on the left bank of the Three Gorges project into the scouring sluice started.

On April 27, 2003, the second phase resettlement project of the Three Gorges project passed the national acceptance. This indicates that the resettlement work of the Three Gorges project has made significant achievements. The resettlement work and the bottom cleaning work of the Three Gorges Reservoir area under the 135 meter water level have been fully completed, meeting the requirements of the Three Gorges Project for water storage on schedule.

On May 21, 2003, the key project acceptance group of the State Council's Three Gorges Project Acceptance Committee officially announced that the Three Gorges project has reached the water level of 135m and the requirements of trial navigation of ships. It is agreed that the Three Gorges Project will be impounded on June 1, and the permanent ship lock can be put into trial navigation in June 2003.

geographical environment

geographical position

Located in the hinterland of China, the Three Gorges of the Yangtze River is the general name of Qutang gorge, Wuxia gorge and Xiling Gorge. It starts from Baidi city in Fengjie County of Chongqing in the west, ends at nanjinguan in Yichang city of Hubei in the East, and crosses Fengjie County of Chongqing, Wushan County of Chongqing, Badong County of Hubei, Zigui County of Hubei and Yichang city of Hubei, with a length of 193 km. It is also known as the "Great Three Gorges".

From west to East, there are three major gorge areas: Qutang gorge in Chongqing, Wu Gorge in Chongqing and Xiling Gorge in Hubei. There are high mountains on both sides of the Three Gorges, with steep cliffs and peaks generally 1000-1500 meters above the river. The narrowest part is less than 100 meters. The Three Gorges area is formed by the rising crust and the strong downward cutting of the Yangtze River.

climatic conditions

The Three Gorges of the Yangtze River belongs to the subtropical monsoon climate zone. In 2001 (December 2000 to November 2001), the climate in the Three Gorges Reservoir area was generally characterized by drought and warm. The annual precipitation is generally low and the temperature is generally high. Compared with the normal season, the precipitation in winter is more than that in spring, summer and autumn. Compared with the normal year, the temperature in winter, autumn, early spring and midsummer is higher, and the temperature in mid spring, early summer and late summer is lower. The average wind speed in the reservoir area is slightly less than that in the whole year, and the seasonal variation is small.

In 2001, the average precipitation in the reservoir area was 932 mm, more than 15% less than that in the normal year. The annual precipitation in all parts of the reservoir area ranges from 800 mm to 1300 mm, about 15% to 30% less. From the regional distribution of precipitation, it has the characteristics of more in the Middle East and less in the West as in 2000. From the time distribution, the precipitation in this year presents a bimodal distribution, the peak appears in June and October respectively, and the precipitation in October is the largest. The precipitation concentration period occurs from April to August, but the precipitation is obviously less than that of the whole year. The average precipitation in spring and summer is 239 mm and 367 mm respectively, which is more than 20% less than that in normal years. The average precipitation in autumn is 235 mm, about 20% less than that in normal years.

In 2001, the average temperature in the reservoir area was 18.1 ℃, which was 0.5 ℃ higher than that in other years. The annual average temperature is 17.0 ~ 19.1 ℃, which is 0.4 ~ 1.1 ℃ higher than normal. The annual average temperature in the west is higher than that in the East, and that in Wanzhou is the highest, 19.1 ℃. The annual average temperature of Fengjie is the lowest, 17.0 ℃. In 2001, the temperature distribution in the reservoir area was higher in winter, autumn, early spring and midsummer, and lower in mid spring, early summer and late summer.

Hydrology and water quality

Water quality

According to the national environmental protection surface water environmental quality standard (ghzb1-1999), 13 indicators such as permanganate index, ammonia nitrogen and volatile phenol were selected for single water quality assessment.

Dry season: the water quality is good, the water quality sections of type I and II account for 87% of the total monitoring sections, and the water quality sections of type III account for 13% of the total monitoring sections.

During the normal water period, the water quality is good, the number of class II water quality sections accounts for 67% of the total number of monitoring sections in the reservoir area, and the number of class III water quality sections accounts for 33% of the total number of monitoring sections.

Wet season: the water quality is acceptable, the number of class II water quality sections accounts for 40% of the total number of monitoring sections in the reservoir area, the number of class III water quality sections accounts for 46.7% of the total number of monitoring sections, and the water quality of only one section is class IV water quality.

In 2001, chemical oxygen consumption, permanganate index and ammonia nitrogen were the main pollution factors affecting the water quality of urban river section in the reservoir area.

In 2001, 100.0%, 100.0% and 93.3% of the urban river sections in the Three Gorges Reservoir area had water quality up to or better than Class III in dry season, wet season and normal season, respectively.

In 2001, the water quality of the main stream of the Yangtze River was generally in good condition. The annual water quality of most sections was class II. Due to the high permanganate index, the annual water quality of the lower section of Wusongkou was class III. In flood season, the water quality decreased, and there was a certain degree of heavy metal pollution, and the main exceeding standard item was total lead. Water quality of tributaries in reservoir area

Chinese PinYin : Zhang Jiang San Xia