River

The Yangtze River is formed by the union of various and important headwaters, the main of which is scientifically that of the Yangtze River. The western headwaters are the Jinsha River, which in turn continues upstream as the Tongtian River and later as the Tuotu River. Starting from the city of Yibin, the Jinsha and Min Rivers – the northern headwaters of the Yangtze – join and the river now definitively adopts the name Yangtze. The Yangtze itself has traditionally been divided into three sections: the upper course, which is considered the section from Yibin to the city of Yichang; the middle course, the one that corresponds to the section between Yichang and Hukou County"), where the river meets Lake Poyang; and the lower course, the section that goes from Hukou to Shanghai, the mouth of the sea.

Three Gorges

The Three Gorges area is described below:

The Qutang Gorge (in Chinese: 瞿塘峡) has 8 km, which makes it the first and the shortest of the three. Downstream from the village of Baidicheng") (Chinese: 白帝城) (Fengjie area) the Yangtze River flows between the Chijia") in the north and the Baiyan") (in Chinese: 白盐山) in the south. From this point is called Kuimen (in Chinese: 夔门) and reaches the Qutang. The Qutang Gorge is 8 km long and is the smallest of the three gorges. The widest point only reaches 150 m. The mountains on both sides are up to 1200 m high. The Qutang gorge is often referred to under these exceptional features as the most beautiful of the three gorges.

The river's strong, sand-banked currents through canyons were already described in the Song era (960-1279) by the poet Su Dongpo in "A Thousand Oceans, Flow into a Cup".

In one of the cliffs there is a series of rectangular holes cut out that form the so-called Meng-Liang Staircase (in Chinese: 孟良梯). The staircase leads to a platform above the mid-height cliffs, where according to legend, the Song general Yang Jiye was killed by traitors.

The Wu Gorge (Chinese: 巫峽) begins at the mouth of the Daning River"), in the area of ​​Wushan "Wushan (Chongqing)") and has a length of 44 km.[26] According to Chinese mythology, a river dragon subdued the Goddess Yao Ji and her eleven sisters, who were frozen in the mountains, but guided the boats with wisdom to maintain safety downstream.

Along the way there is a rock inscription that says "the peaks of Wuxias grow higher and higher", made by navigators traveling during the Three Kingdoms era (220–280 AD), attributed to Zhuge Liang.

The Xiling Gorge (Chinese: 西陵峽) has a length of 66 km and is the easternmost of the gorges. It is located between Xiangxi in the Zigui area and Yichang. At the narrowest point it is 80 m wide.

Travelers from the West, on this stretch of the river, around the , reported sandbanks that emerged as barriers to the river, dangerous bush jumps and threatening rocks, so that smugglers' boats had to be supported by fried bamboo poles. Today, the passage has been restructured in accordance with maritime traffic to make it passable and safe.

Made of concrete and steel, the dam is 2335 m long and the crest of the dam is 185 meters above sea level. The work used 27.2 million cubic meters of concrete (mainly for the dam wall), 463,000 tons of steel (enough to build 63 Eiffel Towers) and about 102.6 million cubic meters of earth were moved.[27] The concrete dam wall is 181 m above the base of the rock.

When the water level is at its maximum of 175 m above sea level, which is 110 m higher than the downstream river level, the reservoir is about 660 kilometers long and 1.12 kilometers wide on average. It contains 39.3 km³ of water and has a total area of ​​1045 square kilometers. When finished, the reservoir floods a total area of ​​632 square kilometers of land, compared to the 1,350 square kilometers of the reservoir created by the Itaipú dam.[28]​.

The government estimated that the Three Gorges Dam project would cost 180 billion yuan (22.5 billion US dollars). relocation of affected residents, and 15.195 billion yuan in financing.[30] It is estimated that the construction cost will be recovered when the dam has generated 1,000 terawatt-hours (3,600 PJ) of electricity, producing 250 billion yuan. Full cost recovery is expected to occur within ten years after the dam begins operation.[29]​.

The sources of financing are the Three Gorges Dam Construction Fund, the proceeds of the Gezhouba Dam, the loan of the China Development Bank, the loans of domestic and foreign commercial banks, corporate bonds, and the income before and after the dam is fully operational. The supplements were evaluated as follows: Each province that receives power from the Three Gorges Dam has to pay ¥7.00 for each extra MWh. Other provinces had to pay an additional charge of ¥4.00 per MWh. Tibet does not pay any supplement.[31]​.

Generative capacity

Power generation is managed by China Yangtze Power, a listed subsidiary of China Three Gorges Corporation (CTGC), a public centralized company managed by SASAC. The Three Gorges Dam is the largest hydroelectric power station in capacity in the world with 34 generators: 32 main generators, each with a capacity of 700 MW, and two power plant generators, each with the capacity of 50 MW, reaching a total capacity of 22,500 MW.[32] Among the 32 main generators, 14 are installed on the north side of the dam, 12 on the south side, and the remaining six from the underground power plant") in the southern mountain range of the dam. The expected annual electricity generation will be more than 100 TWh.[33]​[34]​.

Generators

The main generators weigh over 6000 tons each and are designed to produce more than 700 MW of energy. The design hydraulic head of the generator is 80.6 meters. The flow to the generator varies between 600–950 cubic meters per second depending on the water level. The higher the level, the less water is needed to reach maximum power. The Three Gorges use Francis turbines. The turbine diameter is 9.7/10.4 m (VGS design/Alstom design) and a rotation speed of 75 revolutions per minute. The rated power is 778 MVA, with a maximum of 840 MVA and a power factor of 0.9. The generator produces electrical energy at 20 kV. The outside diameter of the generator stator is 21.4/20.9 m. The inner diameter is 18.5/18.8 m. The stator, the largest of its type, is 3.1/3 m in height. The load on the support is about 5050-5500 tons. The median efficiency is more than 94%, and reaches 96.5%.[35]​[36]​.

The generators are manufactured by two joint ventures and some may include Alstom, ABB Group, Kvaerner), and the Chinese company Haerbin Motor. Others include Voith), General Electric, Siemens (abbreviated as VGS), and the Chinese company Oriental Motor. The technology transfer agreement was signed together with the contract. Most generators are water cooled. Some newer models are air-cooled, which are simpler in design and manufacturing, and are easier to maintain.[37]​.

Generator installation progress

All 14 main generators on the north side are operational. The first (#2) began operation on July 10, 2003. The north side was fully operational on September 7, 2005 with the implementation of generator #9. Full power (9,800 MW) did not arrive until October 18, 2006 after the water level reached 156 m.[38]​.

The 12 main generators on the south side are also in operation. No. 22 began operating on June 11, 2007 and No. 15 began on October 30, 2008.[39]​ The sixth (No. 17) began operating on December 18, 2007 and the generation capacity of the Three Gorges increased to 14.1 GW, higher than that of Itaipú (14.0 GW), with which It became the largest hydroelectric plant in the world by capacity.[40][41][42][43]​.

The six underground main generators have also been in operation since 23 May 2012, when the last main generator, No. 27, completed final testing[44]​ and capacity increased to 22.5 GW. After 9 years of construction, installation and testing, the power plant is now fully operational.[13][45][46][47]​.

Exit milestones

On August 16, 2011, the plant generated 500 TWh of electricity.[59][60]​ In July 2008, it generated 10.3 TWh of electricity, its first month above 10 TWh.[61]​ On June 30, 2009, after the river flow increased by more than 24,000 m³, the 28 generators were activated, producing only 16,100 MW because the available load during the flood season was insufficient.[62]​ During the August 2009 flood, the plant achieved its first maximum production for a short period.[63]​.

During the November to May dry season, power output was limited by river flow, as seen in the diagram to the right. When there is sufficient flow, the power output is limited by the generating capacity of the plant. The maximum output energy curves were calculated based on the median flow at the dam site, assuming that the water level is 175 m and the dirty efficiency of the plant is 90.15%. The actual power output for 2008 was obtained based on the monthly electricity sent to the grid.[64]​[65]​.

The Three Gorges Dam reached its maximum reservoir design water level of 175 m for the first time on October 26, 2010, meeting the planned annual power generation capacity of 84.7 TWh.[21] In 2012, the 32 generating units generated a record 98.1 TWh of electricity, accounting for 14% of China's total electricity generation system. hydraulic.[66]​.

Distribution

State Grid Corporation") and China Southern Power Grid") paid a fixed rate of ¥250 per MWh (US$35.7) until July 2, 2008. Since then, the price has varied by province, from ¥228.7–401.8 per MWh. Customers who pay more have priority, as in the case of Shanghai.[67]​ Nine provinces and two cities consume energy from the dam.[68]​.

Power distribution and transmission infrastructure costs are around 34.387 trillion yuan. Construction was completed in December 2007, a year ahead of schedule.[69]​.

Power is distributed over multiple 500 kilovolt (kV) transmission lines. Three direct current (DC) lines to the East China Grid transport 7,200 MW: Three Gorges – Shanghai") (3,000 MW), HVDC Three Gorges – Changzhou" (3,000 MW), and HVDC Gezhouba – Shanghai") (1,200 MW). The alternating current (AC) lines to the Central China Grid have a total capacity of 12,000 MW. The HVDC direct current transmission line Three Gorges – Guangdong") to the South China Grid has a capacity of 3000 MW.[70]​.

It was anticipated that the dam would provide 10% of China's energy. However, demand for electricity has increased faster than projected. Even fully operational, on average, it supported only about 1.7% of China's electricity demand in 2011, when the country's electricity demand reached 4,692.8 TWh.[71][72]​.

Emissions

According to China's National Development and Reform Commission, 366 grams of coal produces 1 kWh of electricity during 2006.[73]​ At full power, the Three Gorges Dam reduces coal consumption by 31 million tons per year, avoiding 100 million tons of greenhouse gas emissions,[74]​ million tons of dust, one million tons of sulfur dioxide, 370,000 tons of nitrogen monoxide, 10,000 tons of carbon monoxide, and a significant amount of mercury "Mercury (element)").[75] Hydroelectricity saves the energy needed to extract, wash, and transport coal from northern China.

From 2003 to 2007, energy production equaled that of 84 million tons of standard coal, reducing carbon dioxide by 190 million tons, sulfur dioxide by 2.29 million tons, and nitrogen oxides by 980,000 tons.[76]

The dam increased the capacity of Yangtze barges six-fold, reducing carbon dioxide emissions by 630,000 tonnes. From 2004 to 2007 a total of 198 million tons of goods passed through ship locks. Compared to using trucks, barges reduce carbon dioxide emissions by ten million tonnes and costs by 25%.[76]​.

Erosion and sedimentation

There are two dangers identified with the dam.[77]​ One is that sedimentation projections are not recorded, and the other is that the dam is located on top of a seismic fault. At current levels, 80% of the land in the area is experiencing erosion, depositing some 40 million tonnes of sediment annually into the Yangtze.[78] Because flow is slower over the dam, much of this sediment is deposited rather than flowing downstream, which limits the movement of sediment beyond it.

The absence of silt downstream has three effects:

• - Some hydrologists believe that downstream banks will be more vulnerable to flooding.[79]​.

• - Shanghai, more than 1,600 km away, rests on a massive sedimentary plain. "The arrival of silt strengthens the bed on which Shanghai replenishes... with a lower arrival of sediments the vulnerability to floods in the largest Chinese city increases..."[80]​.

• - The accumulation of benthic sediment causes biological damage and reduces aquatic biodiversity.[81]​.

Earthquakes and landslides

Erosion of the reservoir, induced by rising water levels, causes frequent landslides that cause perceptible disturbances to the surface of the reservoir. For example, in May 2009 between 20,000 and 50,000 cubic meters of material was submerged in the flooded Wuxia Gorge of the Wu River.[82] During the first four months of 2010, 97 major landslides were observed.[83] Also, major earthquakes affect the Earth, as well as its rotating axis. To make a comparison about how much is displaced as a result of the earthquake, NASA scientists compare it to the Chinese dam. At its maximum capacity, it would correspond to 40 cubic kilometers of water. This change in density would increase the length of the day by 0.06 microseconds and make the Earth slightly rounder at the center and flatter at the top. This would change the position of the pole by about two centimeters.[84]​.

Waste management

The dam has improved the treatment of upstream wastewater around Chongqing and its suburban areas. According to the Ministry of Environmental Protection, as of April 2007, more than 50 new plants can treat 1.84 million tons per day, 65% of total needs. Some 32 were added to landfills, which can handle 7,664.5 tons of solid waste each day.[85]​ About a billion tons of wastewater are released annually into the river,[78]​ This generates stagnant, polluted and cloudy water.[83]​.

forest area

The Three Gorges area currently has 10% forest afforestation, a figure that was below 20% in the 1950s.[78] FAO research suggests that the Asia-Pacific region, overall, increased forest by approximately 6,000 square km in 2008. This is a reversal given the clear loss of 13,000 square kilometers of forest each year during the 1950s. 1990s. China's reforestation effort began after severe flooding in 1998), which convinced the government to restore forest cover, especially to the Yangtze basin upstream of the Three Gorges Dam.[86]

wildlife

The environmental consequences at the site have been devastating.[87]​ Concern over the potential wildlife impact of the dam predates approval by China's National People's Congress in 1992.[88]​ This region has been known for its rich biodiversity. It is home to 6,388 species of plants, belonging to 238 families and 1,508 genera. Of these plant species, 57 percent are endangered.[89]​ These rare species are also used as ingredients in traditional Chinese medicine.[90]​ The percentage of forest area in the region surrounding the Three Gorges Dam has been reduced from twenty percent in 1950 to less than ten percent as of 2002,[91]​ which negatively affects all plant species in this area. The region also provides habitat for hundreds of species of freshwater and terrestrial animals.[92] Freshwater fish are especially affected by dams due to changes in water temperature and flow regime. Many other fish are harmed by the turbine blades of hydroelectric plants. This is particularly detrimental to the region's ecosystem due to the fact that the Yangtze River basin contains 361 different species of fish and represents twenty-seven percent of all endangered freshwater fish species in China. There are other aquatic species that are endangered by the dam, notably the baiji, or Chinese river dolphin,[92] a species endemic to the Yangtze River, which had been critically endangered. of extinction for decades. The construction of this dam has pushed the conditions that this species of dolphin could withstand to the limit, and finally, in 2008, after exhaustive searches, the baiji was officially declared extinct.[94]​.

Of the remaining 3,000 to 4,000 critically endangered Siberian cranes, a large number wintered in wetlands that were destroyed by the Three Gorges Dam.[95] The dam contributes to the functional extinction of the Yangtze River dolphin or baiji. Although it was close to this level, even at the beginning of construction, the dam further reduced its habitat and increased ship travel, which are among the factors causing what will be its final demise. Additionally, Yangtze sturgeon populations are guaranteed to be "negatively affected" by the dam.[96]​[97]​.

An important function of the dam is to control seasonal flooding, one of the problems that the Yangtze River has historically had. Millions of people live downstream from the dam, in many of the major cities such as Wuhan, Nanjing, and Shanghai located along the river. Next to the river there are large areas of farmland and the most important industrial area in China.[98]​.

The flood storage capacity of the reservoir is 22 cubic kilometers. This capability reduces the frequency of major downstream floods from once every ten years to once every 100 years. The dam is expected to minimize the effect of even a large flood.[99]​[100]​ In 1954, the river flooded 193,000 km², killing 33,169 people and forcing the displacement of 18,884,000 people. The flood covered Wuhan, a city of eight million people, for more than three months, and the Jingguang railway line was out of service. for more than 100 days.[101]​ If there were a flood like those in 1954, which moved 50 cubic kilometers of water, the dam could only divert water above Chenglingji, diverting between 30 to 40 km³.[102]​ Likewise, the dam does not protect against some of the large tributaries downstream, including those of Xiang"), Zishui, Yuanshui"), Lishui"), Hanshui "Han River (Hanshui)"), and the Gan&action=edit&redlink=1 "Gan River (Jiangxi) (not yet drafted)").

In 1998, a flood in the same area caused damages valued at billions of dollars, as 2,039 km² of agricultural land was flooded. The flood also affected 2.3 million people, causing the death of 1,526 people.[103]

The floods of early August 2009 were a trial by fire for the dam, since it was the largest flood it had suffered up to that point. The dam limited the flow to less than 40,000 cubic meters per second, raising the upstream level from 145.13 meters on August 1, 2009, to 152.88 on August 8, 2009. Some 4.27 cubic kilometers of water were captured and the river flow was lowered to 15,000 cubic meters per second. second.[63]​.

The dam discharges its reserve during the dry season between December and March each year.[104] This increases the velocity of the river water downstream, and provides fresh water for agricultural and industrial use. It also improves the conditions of river boat traffic. The level of the reservoir falls from 175 m to 145 m,[105]​ preparing the rainy season. The water also feeds the Gezhouba Dam) downstream.

Since filling the reservoir in 2003, the Three Gorges Dam supplies an extra 11 cubic kilometers of fresh water to downstream cities and farms during the dry season.[106]

During the 2010 South China floods in July, inflows to the Three Gorges Dam peaked at 70,000 m³/s, higher than the maximum during the 1998 Yangtze River floods. The dam's reservoir rose almost 3 m in 24 hours and reduced the outflow of 40,000 m³/s in downstream discharges, alleviating serious impacts to the middle and lower reaches.[107][108][109]​.

Locks

The locks serve to increase river navigation from ten to 100 million tonnes annually, and reduce transport costs by between 30 and 37%. River navigation is safer through the locks, as the gorges are very dangerous to navigate. Ships of much deeper construction will be able to navigate 2,400 km upstream from Shanghai to Chongqing. Chongqing's shipping is expected to increase five-fold.[110]​[111]​.

Near the dam there are two series of boat locks installed, each of which consists of five stages and takes about four hours to make the transit. It is prepared by ships with a maximum size of 10,000 tons.[112]​ The locks are 280 m long, 35 m wide, and 5 m deep.[113]​[114]​ It is 30 m longer than those in the San Lorenzo seaway, but half as deep. Before the dam was built, the maximum carrying capacity in the Three Gorges area was 18.0 million tons per year. From 2004 to 2007, a total of 198 million tons of cargo passed through the locks. The carrying capacity of the river increased six-fold and the cost of boat transportation was reduced by 25%. The total capacity of the ship locks is planned to reach 100 million tons per year.[76]​.

These locks are ladder types, through which the pair of interior gates serve as the upper and lower gate at the same time. Since there are different sets of locks for ascending and descending traffic, this system is more efficient than bidirectional stair locks.

boat lifts

In addition to the canal locks, a boat lift, a type of lift for boats, is under construction. The ship lift is designed to be capable of lifting ships of up to 3,000 tons.[115] According to the original plans there was to be a lift with the capacity to lift 11,500 tons of vessels. The vertical distance traveled had to be 113 meters,[116] and the measurement of the basin of the elevator nave would be 120 x 18 x 3.5 meters. When completed, the boat lift will require 30 to 40 minutes for transit. Before these works it takes between three and four hours to pass through the locks.[117]​ A complicating factor is that the water level can vary considerably. The boat lift will work whenever water levels vary from 12 meters at the bottom, and 30 meters at the top.

The boat lift was not yet finished when the rest of the project was officially opened on May 20, 2006.[118]​[119]​

In November 2007, local media were informed that construction of the boat lift would begin in October 2007 and be completed in 2014.[20]​.

In February 2012, Xinhua reported that the four towers supporting the ship elevator were almost finished, that the most advanced had reached a height of 189 meters of the 185 planned, that the concreting work would be completed in June 2012 and that the elevator would be finished in 2015.[120]​.

The dam's elevator, the largest in the world designed for boats, began operating in 2016, which according to the official press meant the end of 23 years of work on the dam. The structure allows ships with a maximum displacement of 3,000 tons to overcome a difference in level of about , which separates the level of the river before and after the dam.[3]​.

Ships on rails

There are plans to build a short railway line near the dam area. Two short railway lines would be built, one on each side of the river. The 88 km northern railway line (北岸翻坝铁路) would pass through the Taipingxi port facilities (太平溪港) on the north side of the Yangtze, upstream of the dam and through the Yichang East Railway Station) to the Baiyang Tianjiahe port facilities in Baiyang City (白洋镇), by Below Yichang.

At the end of 2012, preliminary work began along the two future railway axes.[122]​.

Contenido

Tanto el Banco Mundial, como diversas organizaciones no gubernamentales y algunos países han criticado la obra desde el principio. Los motivos han sido diversos, no sólo relacionados con el impacto ambiental que supone, sino también por los altos niveles de corrupción a la hora de gestionar los fondos, sobre todo aquellos fondos destinados a llevar a cabo la más grande reubicación de personas de la historia debida a causas de desarrollo. Muchos científicos han criticado esta construcción debido al gran impacto ambiental que representa. Dai Qing, escritora y ecologista china, fue una de las primeras personas que levantó la voz desde el interior, iniciando las actividades de protesta con la realización del documento Yangtsé-Yangtsé!. Fue detenida durante años acusada de ser una de las instigadoras de las protestas de la plaza de Tian'anmen de 1989, y su libro fue prohibido.

Archaeological losses

The flooding of the land caused great losses of objects of historical relevance around the river. Elements from the Paleolithic era, fossil remains, Neolithic settlements, ancestral burials, aristocratic tombs and works from the Ming and Qing dynasties were left below the water level. In 1995, a race against time began to save the largest possible number of these elements.[123]​.

The reservoir, which has a length of 600 km, flooded some 1,300 archaeological sites and altered the appearance of the Three Gorges, as the water level rose by an additional 91 meters.[124] Objects with cultural and historical relevance that could be recovered were moved to higher areas as they were discovered, but the floods inevitably covered those that had not been recovered. Some of those that were located could not be moved due to their location, size or design. A significant example is the area of ​​hanging coffins at the Shen Nong Gorge, which is part of the cliffs.[125]​.

National security

Taiwan used the destruction of the dam as a deterrence policy to defend itself against China, the US Department of Defense reported. Specifically, he indicated that “proponents of attacks against the mainland seem to hope that the mere presentation of credible threats against the urban population of mainland China or high-value targets, such as the Three Gorges Dam, would deter Chinese military coercion.”[126]​.

Reports that military forces in Taiwan were planning to destroy the dam sparked an angry response from mainland Chinese media. People's Liberation Army General "People's Liberation Army (China)") Liu Yuan&action=edit&redlink=1 "Liu Yuan (politician) (not yet redacted)") told China Youth Daily") that the People's Republic of China would be "seriously on guard against threats from Taiwanese independence terrorists."[127]​.

Structural integrity

Days after the reservoir was filled for the first time, some 80 cracks were observed in the dam's structure.[128]​[129]​[130]​ On the other hand, the structure of the submerged water gates could pose a cavitation risk similar to that which severely damaged the poorly designed spillways that affected the Glen Canyon Dam in the state of Arizona, which could not withstand river flooding. Colorado 1983").[131]​ However, the 163,000 concrete units of the Three Gorges Dam passed quality tests and the deformation was within the expected limits. A group of experts concluded that the project as a whole deserved to receive a good quality rating.[132]​.

Displaced and homeless

The Three Gorges Dam forced the displacement of 1.24 million people until June 2008. Of the twelve cities that have been submerged, the last has been Gaoyang"), in Hubei province,[133][134]​ where around 1.5% of the province's 60.3 million inhabitants lived, and the municipal area of Chongqing, which had 31.44 million. people.[135]​ Around 140,000 residents were relocated to other provinces.[136]​ At least 10.2 million people have lost their homes due to the construction of dams throughout China since 1949. The main disadvantage for many of the displaced from the Three Gorges is the loss of their source of income: farmland. 35% of those relocated are landless farmers in the highest areas of the Three. Gorges, where the majority of the population has moved, cultivation becomes more difficult because the relief is mountainous and the quality of the soil is poor.[137]​ This monumental work left 19 cities and 322 towns below the water level, affecting almost 2 million people and submerging some 630 km² of Chinese territory.[138]​.

Furthermore, from the dam to the end of the reservoir, the bank of the Yangtze is a type of framework of cement stakes that cover the base of areas with a high risk of soil erosion. The landslides are a consequence of the growing pressure of too much water, the deforestation that the river has suffered for centuries and the effect of the construction of new cities on already unstable terrain. Under these conditions, the central government has reported that four million more people need to be relocated due to lack of space.[24] The displacement of the population was completed on July 22, 2008.[134] Some reports from 2007 indicated that the municipal area of Chongqing will cause four million more people to decide to move away from the dam in the urban area of Chongqing until 2020.[139]​[140]​[141]​

However, the municipal government defends that the transfer is due to the urbanization, and not to the dam, and the people involved are also from other areas of the municipality.[142]​.

It is claimed that funds for the relocation of 13,000 farmers across Gaoyang disappeared after being sent to local governments, leaving residents without compensation.[143] In total, the work leaves 12 cities and 326 villages under water, covering 630 km² of Chinese territory, affecting a total of 1.24 million people.[144]

Pollution and navigability

In Wuhan (Hubei province), a city of seven million inhabitants located 350 kilometers past the dam, in 2009 the river water level was the lowest in the last 140 years, despite the fact that it had been a winter of heavy rainfall. The main reason was the effort to quickly fill the Three Gorges Reservoir and the increase in urban consumption. The Yangtze was circulating 15 meters below the level it had last year at the same time. The situation was such that the sewage flowed into the river in plain sight of everyone. Furthermore, concern about the state of the river was not only exclusive to China: universities in Japan presented evidence that the reservoir was altering marine currents and the ecosystem of the China Sea, where it flows.[24]​.

The authorities want to build a series of dams downstream of Jinsha to maximize the utility of the Three Gorges and reduce sedimentation of the Jinsha River, upstream of the Yangtze River before reaching Yibin (Sichuan). Among these planned new dams are the Wudongde Dam, Baihetan Dam, government approval. Eight more dams are midstream of the Jinshan and eight more upstream.[147]

• - Still Life (2006) "Still Life (2006 film)"): Chinese film that tells the story of people who are forced to leave their city due to the construction of the dam.

• - World records for buildings and structures.

• - Three Gorges Museum.

• - Wikimedia Commons hosts a multimedia category on Three Gorges Dam.

• - Three gorges in the Aquae foundation: includes interactive graphics.

• - The Three Gorges Dam on the Yangtze River, one of the most iconic water projects in China on CGTN in Spanish.

• - This is the Three Gorges Dam, the largest in the world.

River

The Yangtze River is formed by the union of various and important headwaters, the main of which is scientifically that of the Yangtze River. The western headwaters are the Jinsha River, which in turn continues upstream as the Tongtian River and later as the Tuotu River. Starting from the city of Yibin, the Jinsha and Min Rivers – the northern headwaters of the Yangtze – join and the river now definitively adopts the name Yangtze. The Yangtze itself has traditionally been divided into three sections: the upper course, which is considered the section from Yibin to the city of Yichang; the middle course, the one that corresponds to the section between Yichang and Hukou County"), where the river meets Lake Poyang; and the lower course, the section that goes from Hukou to Shanghai, the mouth of the sea.

Three Gorges

The Three Gorges area is described below:

The Qutang Gorge (in Chinese: 瞿塘峡) has 8 km, which makes it the first and the shortest of the three. Downstream from the village of Baidicheng") (Chinese: 白帝城) (Fengjie area) the Yangtze River flows between the Chijia") in the north and the Baiyan") (in Chinese: 白盐山) in the south. From this point is called Kuimen (in Chinese: 夔门) and reaches the Qutang. The Qutang Gorge is 8 km long and is the smallest of the three gorges. The widest point only reaches 150 m. The mountains on both sides are up to 1200 m high. The Qutang gorge is often referred to under these exceptional features as the most beautiful of the three gorges.

The river's strong, sand-banked currents through canyons were already described in the Song era (960-1279) by the poet Su Dongpo in "A Thousand Oceans, Flow into a Cup".

In one of the cliffs there is a series of rectangular holes cut out that form the so-called Meng-Liang Staircase (in Chinese: 孟良梯). The staircase leads to a platform above the mid-height cliffs, where according to legend, the Song general Yang Jiye was killed by traitors.

The Wu Gorge (Chinese: 巫峽) begins at the mouth of the Daning River"), in the area of ​​Wushan "Wushan (Chongqing)") and has a length of 44 km.[26] According to Chinese mythology, a river dragon subdued the Goddess Yao Ji and her eleven sisters, who were frozen in the mountains, but guided the boats with wisdom to maintain safety downstream.

Along the way there is a rock inscription that says "the peaks of Wuxias grow higher and higher", made by navigators traveling during the Three Kingdoms era (220–280 AD), attributed to Zhuge Liang.

The Xiling Gorge (Chinese: 西陵峽) has a length of 66 km and is the easternmost of the gorges. It is located between Xiangxi in the Zigui area and Yichang. At the narrowest point it is 80 m wide.

Travelers from the West, on this stretch of the river, around the , reported sandbanks that emerged as barriers to the river, dangerous bush jumps and threatening rocks, so that smugglers' boats had to be supported by fried bamboo poles. Today, the passage has been restructured in accordance with maritime traffic to make it passable and safe.

Made of concrete and steel, the dam is 2335 m long and the crest of the dam is 185 meters above sea level. The work used 27.2 million cubic meters of concrete (mainly for the dam wall), 463,000 tons of steel (enough to build 63 Eiffel Towers) and about 102.6 million cubic meters of earth were moved.[27] The concrete dam wall is 181 m above the base of the rock.

When the water level is at its maximum of 175 m above sea level, which is 110 m higher than the downstream river level, the reservoir is about 660 kilometers long and 1.12 kilometers wide on average. It contains 39.3 km³ of water and has a total area of ​​1045 square kilometers. When finished, the reservoir floods a total area of ​​632 square kilometers of land, compared to the 1,350 square kilometers of the reservoir created by the Itaipú dam.[28]​.

The government estimated that the Three Gorges Dam project would cost 180 billion yuan (22.5 billion US dollars). relocation of affected residents, and 15.195 billion yuan in financing.[30] It is estimated that the construction cost will be recovered when the dam has generated 1,000 terawatt-hours (3,600 PJ) of electricity, producing 250 billion yuan. Full cost recovery is expected to occur within ten years after the dam begins operation.[29]​.

The sources of financing are the Three Gorges Dam Construction Fund, the proceeds of the Gezhouba Dam, the loan of the China Development Bank, the loans of domestic and foreign commercial banks, corporate bonds, and the income before and after the dam is fully operational. The supplements were evaluated as follows: Each province that receives power from the Three Gorges Dam has to pay ¥7.00 for each extra MWh. Other provinces had to pay an additional charge of ¥4.00 per MWh. Tibet does not pay any supplement.[31]​.

Generative capacity

Power generation is managed by China Yangtze Power, a listed subsidiary of China Three Gorges Corporation (CTGC), a public centralized company managed by SASAC. The Three Gorges Dam is the largest hydroelectric power station in capacity in the world with 34 generators: 32 main generators, each with a capacity of 700 MW, and two power plant generators, each with the capacity of 50 MW, reaching a total capacity of 22,500 MW.[32] Among the 32 main generators, 14 are installed on the north side of the dam, 12 on the south side, and the remaining six from the underground power plant") in the southern mountain range of the dam. The expected annual electricity generation will be more than 100 TWh.[33]​[34]​.

Generators

The main generators weigh over 6000 tons each and are designed to produce more than 700 MW of energy. The design hydraulic head of the generator is 80.6 meters. The flow to the generator varies between 600–950 cubic meters per second depending on the water level. The higher the level, the less water is needed to reach maximum power. The Three Gorges use Francis turbines. The turbine diameter is 9.7/10.4 m (VGS design/Alstom design) and a rotation speed of 75 revolutions per minute. The rated power is 778 MVA, with a maximum of 840 MVA and a power factor of 0.9. The generator produces electrical energy at 20 kV. The outside diameter of the generator stator is 21.4/20.9 m. The inner diameter is 18.5/18.8 m. The stator, the largest of its type, is 3.1/3 m in height. The load on the support is about 5050-5500 tons. The median efficiency is more than 94%, and reaches 96.5%.[35]​[36]​.

The generators are manufactured by two joint ventures and some may include Alstom, ABB Group, Kvaerner), and the Chinese company Haerbin Motor. Others include Voith), General Electric, Siemens (abbreviated as VGS), and the Chinese company Oriental Motor. The technology transfer agreement was signed together with the contract. Most generators are water cooled. Some newer models are air-cooled, which are simpler in design and manufacturing, and are easier to maintain.[37]​.

Generator installation progress

All 14 main generators on the north side are operational. The first (#2) began operation on July 10, 2003. The north side was fully operational on September 7, 2005 with the implementation of generator #9. Full power (9,800 MW) did not arrive until October 18, 2006 after the water level reached 156 m.[38]​.

The 12 main generators on the south side are also in operation. No. 22 began operating on June 11, 2007 and No. 15 began on October 30, 2008.[39]​ The sixth (No. 17) began operating on December 18, 2007 and the generation capacity of the Three Gorges increased to 14.1 GW, higher than that of Itaipú (14.0 GW), with which It became the largest hydroelectric plant in the world by capacity.[40][41][42][43]​.

The six underground main generators have also been in operation since 23 May 2012, when the last main generator, No. 27, completed final testing[44]​ and capacity increased to 22.5 GW. After 9 years of construction, installation and testing, the power plant is now fully operational.[13][45][46][47]​.

Exit milestones

On August 16, 2011, the plant generated 500 TWh of electricity.[59][60]​ In July 2008, it generated 10.3 TWh of electricity, its first month above 10 TWh.[61]​ On June 30, 2009, after the river flow increased by more than 24,000 m³, the 28 generators were activated, producing only 16,100 MW because the available load during the flood season was insufficient.[62]​ During the August 2009 flood, the plant achieved its first maximum production for a short period.[63]​.

During the November to May dry season, power output was limited by river flow, as seen in the diagram to the right. When there is sufficient flow, the power output is limited by the generating capacity of the plant. The maximum output energy curves were calculated based on the median flow at the dam site, assuming that the water level is 175 m and the dirty efficiency of the plant is 90.15%. The actual power output for 2008 was obtained based on the monthly electricity sent to the grid.[64]​[65]​.

The Three Gorges Dam reached its maximum reservoir design water level of 175 m for the first time on October 26, 2010, meeting the planned annual power generation capacity of 84.7 TWh.[21] In 2012, the 32 generating units generated a record 98.1 TWh of electricity, accounting for 14% of China's total electricity generation system. hydraulic.[66]​.

Distribution

State Grid Corporation") and China Southern Power Grid") paid a fixed rate of ¥250 per MWh (US$35.7) until July 2, 2008. Since then, the price has varied by province, from ¥228.7–401.8 per MWh. Customers who pay more have priority, as in the case of Shanghai.[67]​ Nine provinces and two cities consume energy from the dam.[68]​.

Power distribution and transmission infrastructure costs are around 34.387 trillion yuan. Construction was completed in December 2007, a year ahead of schedule.[69]​.

Power is distributed over multiple 500 kilovolt (kV) transmission lines. Three direct current (DC) lines to the East China Grid transport 7,200 MW: Three Gorges – Shanghai") (3,000 MW), HVDC Three Gorges – Changzhou" (3,000 MW), and HVDC Gezhouba – Shanghai") (1,200 MW). The alternating current (AC) lines to the Central China Grid have a total capacity of 12,000 MW. The HVDC direct current transmission line Three Gorges – Guangdong") to the South China Grid has a capacity of 3000 MW.[70]​.

It was anticipated that the dam would provide 10% of China's energy. However, demand for electricity has increased faster than projected. Even fully operational, on average, it supported only about 1.7% of China's electricity demand in 2011, when the country's electricity demand reached 4,692.8 TWh.[71][72]​.

Emissions

According to China's National Development and Reform Commission, 366 grams of coal produces 1 kWh of electricity during 2006.[73]​ At full power, the Three Gorges Dam reduces coal consumption by 31 million tons per year, avoiding 100 million tons of greenhouse gas emissions,[74]​ million tons of dust, one million tons of sulfur dioxide, 370,000 tons of nitrogen monoxide, 10,000 tons of carbon monoxide, and a significant amount of mercury "Mercury (element)").[75] Hydroelectricity saves the energy needed to extract, wash, and transport coal from northern China.

From 2003 to 2007, energy production equaled that of 84 million tons of standard coal, reducing carbon dioxide by 190 million tons, sulfur dioxide by 2.29 million tons, and nitrogen oxides by 980,000 tons.[76]

The dam increased the capacity of Yangtze barges six-fold, reducing carbon dioxide emissions by 630,000 tonnes. From 2004 to 2007 a total of 198 million tons of goods passed through ship locks. Compared to using trucks, barges reduce carbon dioxide emissions by ten million tonnes and costs by 25%.[76]​.

Erosion and sedimentation

There are two dangers identified with the dam.[77]​ One is that sedimentation projections are not recorded, and the other is that the dam is located on top of a seismic fault. At current levels, 80% of the land in the area is experiencing erosion, depositing some 40 million tonnes of sediment annually into the Yangtze.[78] Because flow is slower over the dam, much of this sediment is deposited rather than flowing downstream, which limits the movement of sediment beyond it.

The absence of silt downstream has three effects:

• - Some hydrologists believe that downstream banks will be more vulnerable to flooding.[79]​.

• - Shanghai, more than 1,600 km away, rests on a massive sedimentary plain. "The arrival of silt strengthens the bed on which Shanghai replenishes... with a lower arrival of sediments the vulnerability to floods in the largest Chinese city increases..."[80]​.

• - The accumulation of benthic sediment causes biological damage and reduces aquatic biodiversity.[81]​.

Earthquakes and landslides

Erosion of the reservoir, induced by rising water levels, causes frequent landslides that cause perceptible disturbances to the surface of the reservoir. For example, in May 2009 between 20,000 and 50,000 cubic meters of material was submerged in the flooded Wuxia Gorge of the Wu River.[82] During the first four months of 2010, 97 major landslides were observed.[83] Also, major earthquakes affect the Earth, as well as its rotating axis. To make a comparison about how much is displaced as a result of the earthquake, NASA scientists compare it to the Chinese dam. At its maximum capacity, it would correspond to 40 cubic kilometers of water. This change in density would increase the length of the day by 0.06 microseconds and make the Earth slightly rounder at the center and flatter at the top. This would change the position of the pole by about two centimeters.[84]​.

Waste management

The dam has improved the treatment of upstream wastewater around Chongqing and its suburban areas. According to the Ministry of Environmental Protection, as of April 2007, more than 50 new plants can treat 1.84 million tons per day, 65% of total needs. Some 32 were added to landfills, which can handle 7,664.5 tons of solid waste each day.[85]​ About a billion tons of wastewater are released annually into the river,[78]​ This generates stagnant, polluted and cloudy water.[83]​.

forest area

The Three Gorges area currently has 10% forest afforestation, a figure that was below 20% in the 1950s.[78] FAO research suggests that the Asia-Pacific region, overall, increased forest by approximately 6,000 square km in 2008. This is a reversal given the clear loss of 13,000 square kilometers of forest each year during the 1950s. 1990s. China's reforestation effort began after severe flooding in 1998), which convinced the government to restore forest cover, especially to the Yangtze basin upstream of the Three Gorges Dam.[86]

wildlife

The environmental consequences at the site have been devastating.[87]​ Concern over the potential wildlife impact of the dam predates approval by China's National People's Congress in 1992.[88]​ This region has been known for its rich biodiversity. It is home to 6,388 species of plants, belonging to 238 families and 1,508 genera. Of these plant species, 57 percent are endangered.[89]​ These rare species are also used as ingredients in traditional Chinese medicine.[90]​ The percentage of forest area in the region surrounding the Three Gorges Dam has been reduced from twenty percent in 1950 to less than ten percent as of 2002,[91]​ which negatively affects all plant species in this area. The region also provides habitat for hundreds of species of freshwater and terrestrial animals.[92] Freshwater fish are especially affected by dams due to changes in water temperature and flow regime. Many other fish are harmed by the turbine blades of hydroelectric plants. This is particularly detrimental to the region's ecosystem due to the fact that the Yangtze River basin contains 361 different species of fish and represents twenty-seven percent of all endangered freshwater fish species in China. There are other aquatic species that are endangered by the dam, notably the baiji, or Chinese river dolphin,[92] a species endemic to the Yangtze River, which had been critically endangered. of extinction for decades. The construction of this dam has pushed the conditions that this species of dolphin could withstand to the limit, and finally, in 2008, after exhaustive searches, the baiji was officially declared extinct.[94]​.

Of the remaining 3,000 to 4,000 critically endangered Siberian cranes, a large number wintered in wetlands that were destroyed by the Three Gorges Dam.[95] The dam contributes to the functional extinction of the Yangtze River dolphin or baiji. Although it was close to this level, even at the beginning of construction, the dam further reduced its habitat and increased ship travel, which are among the factors causing what will be its final demise. Additionally, Yangtze sturgeon populations are guaranteed to be "negatively affected" by the dam.[96]​[97]​.

An important function of the dam is to control seasonal flooding, one of the problems that the Yangtze River has historically had. Millions of people live downstream from the dam, in many of the major cities such as Wuhan, Nanjing, and Shanghai located along the river. Next to the river there are large areas of farmland and the most important industrial area in China.[98]​.

The flood storage capacity of the reservoir is 22 cubic kilometers. This capability reduces the frequency of major downstream floods from once every ten years to once every 100 years. The dam is expected to minimize the effect of even a large flood.[99]​[100]​ In 1954, the river flooded 193,000 km², killing 33,169 people and forcing the displacement of 18,884,000 people. The flood covered Wuhan, a city of eight million people, for more than three months, and the Jingguang railway line was out of service. for more than 100 days.[101]​ If there were a flood like those in 1954, which moved 50 cubic kilometers of water, the dam could only divert water above Chenglingji, diverting between 30 to 40 km³.[102]​ Likewise, the dam does not protect against some of the large tributaries downstream, including those of Xiang"), Zishui, Yuanshui"), Lishui"), Hanshui "Han River (Hanshui)"), and the Gan&action=edit&redlink=1 "Gan River (Jiangxi) (not yet drafted)").

In 1998, a flood in the same area caused damages valued at billions of dollars, as 2,039 km² of agricultural land was flooded. The flood also affected 2.3 million people, causing the death of 1,526 people.[103]

The floods of early August 2009 were a trial by fire for the dam, since it was the largest flood it had suffered up to that point. The dam limited the flow to less than 40,000 cubic meters per second, raising the upstream level from 145.13 meters on August 1, 2009, to 152.88 on August 8, 2009. Some 4.27 cubic kilometers of water were captured and the river flow was lowered to 15,000 cubic meters per second. second.[63]​.

The dam discharges its reserve during the dry season between December and March each year.[104] This increases the velocity of the river water downstream, and provides fresh water for agricultural and industrial use. It also improves the conditions of river boat traffic. The level of the reservoir falls from 175 m to 145 m,[105]​ preparing the rainy season. The water also feeds the Gezhouba Dam) downstream.

Since filling the reservoir in 2003, the Three Gorges Dam supplies an extra 11 cubic kilometers of fresh water to downstream cities and farms during the dry season.[106]

During the 2010 South China floods in July, inflows to the Three Gorges Dam peaked at 70,000 m³/s, higher than the maximum during the 1998 Yangtze River floods. The dam's reservoir rose almost 3 m in 24 hours and reduced the outflow of 40,000 m³/s in downstream discharges, alleviating serious impacts to the middle and lower reaches.[107][108][109]​.

Locks

The locks serve to increase river navigation from ten to 100 million tonnes annually, and reduce transport costs by between 30 and 37%. River navigation is safer through the locks, as the gorges are very dangerous to navigate. Ships of much deeper construction will be able to navigate 2,400 km upstream from Shanghai to Chongqing. Chongqing's shipping is expected to increase five-fold.[110]​[111]​.

Near the dam there are two series of boat locks installed, each of which consists of five stages and takes about four hours to make the transit. It is prepared by ships with a maximum size of 10,000 tons.[112]​ The locks are 280 m long, 35 m wide, and 5 m deep.[113]​[114]​ It is 30 m longer than those in the San Lorenzo seaway, but half as deep. Before the dam was built, the maximum carrying capacity in the Three Gorges area was 18.0 million tons per year. From 2004 to 2007, a total of 198 million tons of cargo passed through the locks. The carrying capacity of the river increased six-fold and the cost of boat transportation was reduced by 25%. The total capacity of the ship locks is planned to reach 100 million tons per year.[76]​.

These locks are ladder types, through which the pair of interior gates serve as the upper and lower gate at the same time. Since there are different sets of locks for ascending and descending traffic, this system is more efficient than bidirectional stair locks.

boat lifts

In addition to the canal locks, a boat lift, a type of lift for boats, is under construction. The ship lift is designed to be capable of lifting ships of up to 3,000 tons.[115] According to the original plans there was to be a lift with the capacity to lift 11,500 tons of vessels. The vertical distance traveled had to be 113 meters,[116] and the measurement of the basin of the elevator nave would be 120 x 18 x 3.5 meters. When completed, the boat lift will require 30 to 40 minutes for transit. Before these works it takes between three and four hours to pass through the locks.[117]​ A complicating factor is that the water level can vary considerably. The boat lift will work whenever water levels vary from 12 meters at the bottom, and 30 meters at the top.

The boat lift was not yet finished when the rest of the project was officially opened on May 20, 2006.[118]​[119]​

In November 2007, local media were informed that construction of the boat lift would begin in October 2007 and be completed in 2014.[20]​.

In February 2012, Xinhua reported that the four towers supporting the ship elevator were almost finished, that the most advanced had reached a height of 189 meters of the 185 planned, that the concreting work would be completed in June 2012 and that the elevator would be finished in 2015.[120]​.

The dam's elevator, the largest in the world designed for boats, began operating in 2016, which according to the official press meant the end of 23 years of work on the dam. The structure allows ships with a maximum displacement of 3,000 tons to overcome a difference in level of about , which separates the level of the river before and after the dam.[3]​.

Ships on rails

There are plans to build a short railway line near the dam area. Two short railway lines would be built, one on each side of the river. The 88 km northern railway line (北岸翻坝铁路) would pass through the Taipingxi port facilities (太平溪港) on the north side of the Yangtze, upstream of the dam and through the Yichang East Railway Station) to the Baiyang Tianjiahe port facilities in Baiyang City (白洋镇), by Below Yichang.

At the end of 2012, preliminary work began along the two future railway axes.[122]​.

Contenido

Tanto el Banco Mundial, como diversas organizaciones no gubernamentales y algunos países han criticado la obra desde el principio. Los motivos han sido diversos, no sólo relacionados con el impacto ambiental que supone, sino también por los altos niveles de corrupción a la hora de gestionar los fondos, sobre todo aquellos fondos destinados a llevar a cabo la más grande reubicación de personas de la historia debida a causas de desarrollo. Muchos científicos han criticado esta construcción debido al gran impacto ambiental que representa. Dai Qing, escritora y ecologista china, fue una de las primeras personas que levantó la voz desde el interior, iniciando las actividades de protesta con la realización del documento Yangtsé-Yangtsé!. Fue detenida durante años acusada de ser una de las instigadoras de las protestas de la plaza de Tian'anmen de 1989, y su libro fue prohibido.

Archaeological losses

The flooding of the land caused great losses of objects of historical relevance around the river. Elements from the Paleolithic era, fossil remains, Neolithic settlements, ancestral burials, aristocratic tombs and works from the Ming and Qing dynasties were left below the water level. In 1995, a race against time began to save the largest possible number of these elements.[123]​.

The reservoir, which has a length of 600 km, flooded some 1,300 archaeological sites and altered the appearance of the Three Gorges, as the water level rose by an additional 91 meters.[124] Objects with cultural and historical relevance that could be recovered were moved to higher areas as they were discovered, but the floods inevitably covered those that had not been recovered. Some of those that were located could not be moved due to their location, size or design. A significant example is the area of ​​hanging coffins at the Shen Nong Gorge, which is part of the cliffs.[125]​.

National security

Taiwan used the destruction of the dam as a deterrence policy to defend itself against China, the US Department of Defense reported. Specifically, he indicated that “proponents of attacks against the mainland seem to hope that the mere presentation of credible threats against the urban population of mainland China or high-value targets, such as the Three Gorges Dam, would deter Chinese military coercion.”[126]​.

Reports that military forces in Taiwan were planning to destroy the dam sparked an angry response from mainland Chinese media. People's Liberation Army General "People's Liberation Army (China)") Liu Yuan&action=edit&redlink=1 "Liu Yuan (politician) (not yet redacted)") told China Youth Daily") that the People's Republic of China would be "seriously on guard against threats from Taiwanese independence terrorists."[127]​.

Structural integrity

Days after the reservoir was filled for the first time, some 80 cracks were observed in the dam's structure.[128]​[129]​[130]​ On the other hand, the structure of the submerged water gates could pose a cavitation risk similar to that which severely damaged the poorly designed spillways that affected the Glen Canyon Dam in the state of Arizona, which could not withstand river flooding. Colorado 1983").[131]​ However, the 163,000 concrete units of the Three Gorges Dam passed quality tests and the deformation was within the expected limits. A group of experts concluded that the project as a whole deserved to receive a good quality rating.[132]​.

Displaced and homeless

The Three Gorges Dam forced the displacement of 1.24 million people until June 2008. Of the twelve cities that have been submerged, the last has been Gaoyang"), in Hubei province,[133][134]​ where around 1.5% of the province's 60.3 million inhabitants lived, and the municipal area of Chongqing, which had 31.44 million. people.[135]​ Around 140,000 residents were relocated to other provinces.[136]​ At least 10.2 million people have lost their homes due to the construction of dams throughout China since 1949. The main disadvantage for many of the displaced from the Three Gorges is the loss of their source of income: farmland. 35% of those relocated are landless farmers in the highest areas of the Three. Gorges, where the majority of the population has moved, cultivation becomes more difficult because the relief is mountainous and the quality of the soil is poor.[137]​ This monumental work left 19 cities and 322 towns below the water level, affecting almost 2 million people and submerging some 630 km² of Chinese territory.[138]​.

Furthermore, from the dam to the end of the reservoir, the bank of the Yangtze is a type of framework of cement stakes that cover the base of areas with a high risk of soil erosion. The landslides are a consequence of the growing pressure of too much water, the deforestation that the river has suffered for centuries and the effect of the construction of new cities on already unstable terrain. Under these conditions, the central government has reported that four million more people need to be relocated due to lack of space.[24] The displacement of the population was completed on July 22, 2008.[134] Some reports from 2007 indicated that the municipal area of Chongqing will cause four million more people to decide to move away from the dam in the urban area of Chongqing until 2020.[139]​[140]​[141]​

However, the municipal government defends that the transfer is due to the urbanization, and not to the dam, and the people involved are also from other areas of the municipality.[142]​.

It is claimed that funds for the relocation of 13,000 farmers across Gaoyang disappeared after being sent to local governments, leaving residents without compensation.[143] In total, the work leaves 12 cities and 326 villages under water, covering 630 km² of Chinese territory, affecting a total of 1.24 million people.[144]

Pollution and navigability

In Wuhan (Hubei province), a city of seven million inhabitants located 350 kilometers past the dam, in 2009 the river water level was the lowest in the last 140 years, despite the fact that it had been a winter of heavy rainfall. The main reason was the effort to quickly fill the Three Gorges Reservoir and the increase in urban consumption. The Yangtze was circulating 15 meters below the level it had last year at the same time. The situation was such that the sewage flowed into the river in plain sight of everyone. Furthermore, concern about the state of the river was not only exclusive to China: universities in Japan presented evidence that the reservoir was altering marine currents and the ecosystem of the China Sea, where it flows.[24]​.

The authorities want to build a series of dams downstream of Jinsha to maximize the utility of the Three Gorges and reduce sedimentation of the Jinsha River, upstream of the Yangtze River before reaching Yibin (Sichuan). Among these planned new dams are the Wudongde Dam, Baihetan Dam, government approval. Eight more dams are midstream of the Jinshan and eight more upstream.[147]

• - Still Life (2006) "Still Life (2006 film)"): Chinese film that tells the story of people who are forced to leave their city due to the construction of the dam.

• - World records for buildings and structures.

• - Three Gorges Museum.

• - Wikimedia Commons hosts a multimedia category on Three Gorges Dam.

• - Three gorges in the Aquae foundation: includes interactive graphics.

• - The Three Gorges Dam on the Yangtze River, one of the most iconic water projects in China on CGTN in Spanish.

• - This is the Three Gorges Dam, the largest in the world.