Aerial photo taken on Sept. 23, 2020 shows a view of Caka Salt Lake in Wulan County, northwest China's Qinghai Province. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income. (Photos: Xinhua)

Aerial photo taken on Sept. 23, 2020 shows a hot air balloon by the Qinghai Lake in northwest China's Qinghai Province. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

People visit Caka Salt Lake in Wulan County of northwest China's Qinghai Province, Sept. 23, 2020. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

Aerial photo taken on Sept. 23, 2020 shows people visiting Qinghai Lake in northwest China's Qinghai Province. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

Aerial photo taken on Sept. 22, 2020 shows a village in Wulan County of northwest China's Qinghai Province. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

Aerial photo taken on Sept. 23, 2020 shows a view of Caka Salt Lake in Wulan County, northwest China's Qinghai Province. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

People visit Qinghai Lake in northwest China's Qinghai Province, Sept. 23, 2020. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

People visit Caka Salt Lake in Wulan County of northwest China's Qinghai Province, Sept. 23, 2020. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

Aerial photo taken on Sept. 23, 2020 shows a view of Caka Salt Lake in Wulan County, northwest China's Qinghai Province. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

People visit Caka Salt Lake in Wulan County of northwest China's Qinghai Province, Sept. 23, 2020. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

People visit Caka Salt Lake in Wulan County of northwest China's Qinghai Province, Sept. 23, 2020. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.

A tourist poses for photo as she visits Qinghai Lake in northwest China's Qinghai Province, Sept. 23, 2020. Thanks to the Qinghai-Tibet Railway and its extension railways, many tourist attractions in the province have been connected, which significantly promoted the tourism industry here and helped locals increase income.