Aerial photo taken on July 2, 2019 shows the Hukou Waterfall in its flood period on the Yellow River in Linfen, north China's Shanxi Province. (Photo: Xinhua)

Aerial photo taken on July 2, 2019 shows the Hukou Waterfall in its flood period on the Yellow River in Linfen, north China's Shanxi Province.(Photo: Xinhua)

Aerial photo taken on July 2, 2019 shows the Hukou Waterfall in its flood period on the Yellow River in Linfen, north China's Shanxi Province. (Photo: Xinhua)

Aerial photo taken on July 2, 2019 shows the Hukou Waterfall in its flood period on the Yellow River in Linfen, north China's Shanxi Province. (Photo: Xinhua)