Photo taken on Dec. 10, 2020 shows scenery of taxodium trees near the Yangtze River in Dazhou Town, Wanzhou District of southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved. (Photos: Xinhua)

Photo taken on Dec. 27, 2019 shows a wild macaque at the Small Three Gorges scenic area in Wushan County, southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Aerial photo taken on May 29, 2020 shows the view of Qutang Gorge, one of the Three Gorges on the Yangtze River, in southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Photo taken on Nov. 11, 2020 shows black-headed gulls near the Jijiang Yangtze River Bridge in Jiangjin District of southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Photo taken on May 6, 2020 shows a view of southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Aerial photo taken on Dec. 21, 2019 shows the view of Baidicheng in southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Photo taken on Dec. 10, 2020 shows scenery of taxodium trees near the Yangtze River in Dazhou Town, Wanzhou District of southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Photo taken on Dec. 27, 2019 shows wild macaques at the Small Three Gorges scenic area in Wushan County, southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

A ship sails through the Wuxia Gorge, one of the Three Gorges on the Yangtze River, in Wushan County, southwest China's Chongqing Municipality, Nov. 23, 2019. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Aerial photo taken on March 28, 2019 shows a view of the Qutang Gorge, one of the Three Gorges on the Yangtze River, in southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved. (Xinhua/Wang Quanchao)

Staff members work on a tributary of the Yangtze River in Dianjiang County, southwest China's Chongqing, July 25, 2020. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Aerial photo taken on March 6, 2020 shows workers working at the site of the ecological restoration project at Guangyang Isle of Nan'an District, southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Aerial photo taken on June 4, 2020 shows a nursery near the Yangtze River, in southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

Aerial photo taken on May 26, 2020 shows the view of Yutouwan on a tributary of the Yangtze River in Wushan County, southwest China's Chongqing. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.

A ship sails through the Wuxia Gorge, one of the Three Gorges on the Yangtze River, in Wushan County, southwest China's Chongqing Municipality, Nov. 23, 2019. In recent years, Chongqing has continuously built up important ecological barriers in the upper reaches of the Yangtze River by strengthening ecological restoration. The ecological environment in the Chongqing section of the Yangtze River has been continuously improved.