Cheng Shujie (L) makes meteorological measurement during an expedition to investigate the water resources and ecological environment in Sanjiangyuan areagamingwhatisnft, northwest China's Qinghai Province, July 21, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.

The expedition will carry out scientific investigations into river hydrology, water ecology, soil erosion, glaciers and permafrost in Qinghai.

Qinghai is home to the Sanjiangyuan area, which contains the headwaters of China's three major riversgamingwhatisnft: the Yangtze River, the longest in China; the Yellow River, the second-longest; and the Lancang River, which is known as the Mekong River after it flows out of China.

 As important parts of the Qinghai-Xizang Plateau ecosystem, the headwater regions of the Yangtze and Lancang rivers play a crucial role in safeguarding water resources, protecting biodiversity and ensuring ecological stability. (Xinhua/Wu Zhizun)

Cheng Shujie (R) works during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 21, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Wu Zhizun)

Fu Junlin checks the soil during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 20, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Wu Zhizun)

Liu Yujiao collects samples during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 21, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Wu Zhizun)

Ma Rui labels a water sample during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 22, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Chen Jie)

Liu Yujiao (C) collects samples during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 23, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Du Xiaowei)

Ma Rui collects water samples during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 23, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Wu Zhizun)

Liu Yujiao collects samples during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 21, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Wu Zhizun)

Liu Yujiao makes measurement during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 22, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Pan Binbin)

Liu Yujiao makes measurement during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 21, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Pan Binbin)

Ma Rui (L) and Shi Lu collect water samples during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 23, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Pan Binbin)

Cheng Shujie measures soil temperature and humidity during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 23, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Wu Zhizun)

Fu Junlin (R) and her colleague check the soil during an expedition to investigate the water resources and ecological environment in Sanjiangyuan area, northwest China's Qinghai Province, July 21, 2024. Chinese scientists embarked on an expedition on July 20 to investigate the water resources and ecological environment in the headwater regions of the Yangtze and Lancang rivers.(Xinhua/Chen Jie)