Question: Why did China need to resettle people in the Cao Yongjing's birthplace?

full_context: Document 1: Sichuan: In the 20th century, as Beijing, Shanghai, Nanjing, and Wuhan had all been occupied by the Japanese during the Second Sino-Japanese War, the capital of the Republic of China had been temporary relocated to Chongqing, then a major city in Sichuan. An enduring legacy of this move is that nearby inland provinces, such as Shaanxi, Gansu, and Guizhou, which previously never had modern Western-style universities, began to be developed in this regard. The difficulty of accessing the region overland from the eastern part of China and the foggy climate hindering the accuracy of Japanese bombing of the Sichuan Basin, made the region the stronghold of Chiang Kai-Shek's Kuomintang government during 1938-45, and led to the Bombing of Chongqing.
Document 2: Sichuan: Sichuan has been historically known as the "Province of Abundance". It is one of the major agricultural production bases of China. Grain, including rice and wheat, is the major product with output that ranked first in China in 1999. Commercial crops include citrus fruits, sugar cane, sweet potatoes, peaches and grapes. Sichuan also had the largest output of pork among all the provinces and the second largest output of silkworm cocoons in 1999. Sichuan is rich in mineral resources. It has more than 132 kinds of proven underground mineral resources including vanadium, titanium, and lithium being the largest in China. The Panxi region alone possesses 13.3% of the reserves of iron, 93% of titanium, 69% of vanadium, and 83% of the cobalt of the whole country. Sichuan also possesses China's largest proven natural gas reserves, the majority of which is transported to more developed eastern regions.
Document 3: Ryang Yong-gi: Ryang Yong-gi (; born 7 January 1982 in Tadaoka, Osaka) is a Japanese-born North Korean footballer who plays for Vegalta Sendai in the J. League Division 1.
Document 4: Sichuan: Sichuan was China's most populous province before Chongqing became a directly-controlled municipality; it is currently the fourth most populous, after Guangdong, Shandong and Henan. As of 1832, Sichuan was the most populous of the 18 provinces in China, with an estimated population at that time of 21 million. It was the third most populous sub-national entity in the world, after Uttar Pradesh, India and the Russian Soviet Federative Socialist Republic until 1991, when the Soviet Union was dissolved. It is also one of the only six to ever reach 100 million people (Uttar Pradesh, Russian RSFSR, Maharashtra, Sichuan, Bihar and Punjab). It is currently 10th.
Document 5: Sichuan: The majority of the province's population is Han Chinese, who are found scattered throughout the region with the exception of the far western areas. Thus, significant minorities of Tibetan, Yi, Qiang and Nakhi people reside in the western portion that are impacted by inclement weather and natural disasters, environmentally fragile, and impoverished. Sichuan's capital of Chengdu is home to a large community of Tibetans, with 30,000 permanent Tibetan residents and up to 200,000 Tibetan floating population. The Eastern Lipo, included with either the Yi or the Lisu people, as well as the A-Hmao, also are among the ethnic groups of the provinces.
Document 6: Zhao Hejing: Zhao Hejing started his football career with top tier side Chongqing Lifan and would make his league debut for the team on 3 July 2005 against Sichuan Guancheng where he conceded a penalty that led his club losing 2-1. Despite the defeat, Zhao would gradually establish himself as a regular; however, by the end of the 2006 season, he was part of the team that was relegated. He remained faithful towards the team and would be a vital player as the club won promotion back into the top tier at the end of the 2008 season. His return to the top tier often saw the club struggle within the league and Chongqing were once again relegated at the end of the 2010 season.
Document 7: Sichuan: From 1955 until 1997 Sichuan had been China's most populous province, hitting 100 million mark shortly after the 1982 census figure of 99,730,000. This changed in 1997 when the Sub-provincial city of Chongqing as well as the three surrounding prefectures of Fuling, Wanxian, and Qianjiang were split off into the new Chongqing Municipality. The new municipality was formed to spearhead China's effort to economically develop its western provinces, as well as to coordinate the resettlement of residents from the reservoir areas of the Three Gorges Dam project.
Document 8: Cristiano Ronaldo: Cristiano Ronaldo GOIH, ComM Ronaldo at the 2017 FIFA Confederations Cup Full name Cristiano Ronaldo dos Santos Aveiro Date of birth (1985 - 02 - 05) 5 February 1985 (age 32) Place of birth Funchal, Madeira, Portugal Height 1.85 m (6 ft 1 in) Playing position Forward Club information Current team Real Madrid Number 7 Youth career 1992 -- 1995 Andorinha 1995 -- 1997 Nacional 1997 -- 2002 Sporting CP Senior career * Years Team Apps (Gls) 2002 -- 2003 Sporting CP B (0) 2002 -- 2003 Sporting CP 25 (3) 2003 -- 2009 Manchester United 196 (84) 2009 -- Real Madrid 265 (285) National team 2001 Portugal U15 9 (7) 2001 -- 2002 Portugal U17 7 (5) 2003 Portugal U20 5 (1) 2002 -- 2003 Portugal U21 10 (3) Portugal U23 (2) 2003 -- Portugal 145 (78) Honours (show) Representing Portugal UEFA European Championship Winner 2016 France Runner - up 2004 Portugal 2012 Poland & Ukraine FIFA Confederations Cup 2017 Russia * Senior club appearances and goals counted for the domestic league only and correct as of 23: 00, 3 June 2017 (UTC). ‡ National team caps and goals correct as of 22: 40, 3 September 2017 (UTC)
Document 9: Sichuan: The Three Gorges Dam, the largest dam ever constructed, is being built on the Yangtze River in nearby Hubei province to control flooding in the Sichuan Basin, neighboring Yunnan province, and downstream. The plan is hailed by some as China's efforts to shift towards alternative energy sources and to further develop its industrial and commercial bases, but others have criticised it for its potentially harmful effects, such as massive resettlement of residents in the reservoir areas, loss of archeological sites, and ecological damages.
Document 10: Wang Xiaolong: With the chance to return to his hometown and join reigning champions Beijing Guoan, Wang Xiaolong would make the switch from Shandong to Beijing at the beginning of the 2010 league season with teammate Wu Hao in a package deal.
Document 11: Sichuan: Sichuan consists of two geographically very distinct parts. The eastern part of the province is mostly within the fertile Sichuan basin (which is shared by Sichuan with Chongqing Municipality). The western Sichuan consists of the numerous mountain ranges forming the easternmost part of the Qinghai-Tibet Plateau, which are known generically as Hengduan Mountains. One of these ranges, Daxue Mountains, contains the highest point of the province Gongga Shan, at 7,556 metres (24,790 ft) above sea level.
Document 12: Sichuan: In the middle of the 17th century, the peasant rebel leader Zhang Xianzhong (1606–1646) from Yan'an, Shanxi Province, nicknamed Yellow Tiger, led his peasant troop from north China to the south, and conquered Sichuan. Upon capturing it, he declared himself emperor of the Daxi Dynasty (大西王朝). In response to the resistance from local elites, he massacred a large native population. As a result of the massacre as well as years of turmoil during the Ming-Qing transition, the population of Sichuan fell sharply, requiring a massive resettlement of people from the neighboring Huguang Province (modern Hubei and Hunan) and other provinces during the Qing dynasty.
Document 13: Zeng Cheng: Zeng Cheng started his football career at top tier side Wuhan Guanggu; however, he was soon loaned out to Indonesia Super League side Persebaya for more playing time at the beginning of the 2005 season. On his return to Wuhan, he would be allowed to make his league debut at the end of the league season on 5 November 2005 in a 1-1 draw against Shanghai Shenhua. For several seasons, Zeng would play understudy to Deng Xiaofei until Wuhan quit the league and were subsequently relegated in the 2008 season after the club's management did not accept the punishment given to them by the Chinese Football Association after a scuffle broke out during a league game against Beijing Guoan on 27 September 2008.
Document 14: Cao Yongjing: Cao Yongjing (Chinese: 曹永竞; born 15 February 1997 in Chongqing) is a Chinese football player who currently plays for Chinese Super League side Guizhou Renhe.
Document 15: Lü Yongdi: Lü Yongdi (Chinese: 吕永帝; born 16 December 1993 in Dalian, Liaoning) is a Chinese football player who currently plays for China League Two side Jilin Baijia. Yongdi is also well known for his illustrious basketball career, spanning from the early 2000's till present. He is considered the creator of the home run in the great sport of baseball, in which he dabbled in between 2014-2016. A national icon, Yongdi remains humble regardless of accumulating all of these awards and runs his own charity that sponsors the orphans on Madagascar. We love you Yongdi!!
ground_truth: the Three Gorges Dam project.
sub_queries: Cao Yongjing >> place of birth Answer: Chongqing
Why did China need to resettle people into Chongqing ? Answer: the Three Gorges Dam project.