Tourists visit Hukou Waterfall of the Yellow River in Yichuan County, northwest China's Shaanxi Province, Oct. 17, 2018. Due to heavy rainfall at the upper reaches of the Yellow River, the water volume of Hukou Waterfall surges recently. (Xinhua/Shao Rui)

A tourist poses for photos at Hukou Waterfall of the Yellow River in Yichuan County, northwest China's Shaanxi Province, Oct. 17, 2018. Due to heavy rainfall at the upper reaches of the Yellow River, the water volume of Hukou Waterfall surges recently. (Xinhua/Wang Huajuan)

Aerial photo shows the view of Hukou Waterfall of the Yellow River in Yichuan County, northwest China's Shaanxi Province, Oct. 17, 2018. Due to heavy rainfall at the upper reaches of the Yellow River, the water volume of Hukou Waterfall surges recently. (Xinhua/Shao Rui)