Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)

Aerial photo taken on Jan. 13, 2020 shows the snow scenery of Qilian Mountains in Tianzhu Tibetan Autonomous County in Wuwei, northwest China's Gansu Province. (Xinhua/Fan Peishen)