Staff members patrol the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This aerial photo taken on July 7, 2023 shows the scenery of the Gahai Lake in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

A staff member checks an infrared camera in the Shouqu National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 5, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Fang Xin)

Staff members patrol the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Fang Xin)

This photo taken on July 7, 2023 shows bar-headed geese in Gahai Lake in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This photo taken on July 7, 2023 shows a tern flying over the Gahai Lake wetland in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This photo taken on July 7, 2023 shows bar-headed geese at the Gahai Lake wetland in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Zhang Keren)

This aerial photo taken on July 7, 2023 shows the Gahai Lake wetland in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This aerial photo taken on July 7, 2023 shows the scenery of the Gahai Lake wetland in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Zhang Keren)

A staff member (1st L) briefs tourists on the situation of the wild animals and plants in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This aerial photo taken on July 7, 2023 shows the scenery of Gahai Lake in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This photo taken on July 7, 2023 shows a tern flying over the Gahai Lake wetland in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This aerial photo taken on July 7, 2023 shows the scenery of Gahai Lake in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Zhang Keren)

This photo taken on July 7, 2023 shows bar-headed geese at the Gahai Lake wetland in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

Staff members observe wild animals in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

Staff members patrol the Shouqu National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 5, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

Staff members patrol the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Fang Xin)

Staff members observe wild animals in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)

This aerial photo taken on July 7, 2023 shows the scenery of the Gahai Lake in the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Zhang Keren)

Staff members patrol the Gahai-Zecha National Nature Reserve in Gannan Tibetan Autonomous Prefecture, northwest China's Gansu Province, on July 7, 2023.

Gannan Tibetan Autonomous Prefecture serves as a vital water reserve for the Yellow River, the second longest waterway in China.

Gannan has a 433-kilometer stretch of the Yellow River. The water supplement in Gannan accounted for about half the river's total runoff at the source region.

To better guard the ecology of this area, staff members of the national nature reserves in Gannan have spared no efforts in protecting wild animals and plants on the plateau.

Thanks to their long-term hard work, the deterioration of the natural and ecological environment in the region has been radically curbed, and Gannan has witnessed the rising population of diverse wild animals. (Xinhua/Chen Bin)