The color of Hukou Waterfall of the Yellow River turns into crystal green in Jixian County, Linfen City, north China's Shanxi Province, August 14, 2021. Due to the drought and lack of rain in the upper reaches of the Yellow River, which slows the river's flow, the waterfall turned green. (Photo: China News Service/Lu Guiming)

The color of Hukou Waterfall of the Yellow River turns into crystal green in Jixian County, Linfen City, north China's Shanxi Province, August 14, 2021. Due to the drought and lack of rain in the upper reaches of the Yellow River, which slows the river's flow, the waterfall turned green. (Photo: China News Service/Lu Guiming)

The color of Hukou Waterfall of the Yellow River turns into crystal green in Jixian County, Linfen City, north China's Shanxi Province, August 14, 2021. Due to the drought and lack of rain in the upper reaches of the Yellow River, which slows the river's flow, the waterfall turned green. (Photo: China News Service/Lu Guiming)

The color of Hukou Waterfall of the Yellow River turns into crystal green in Jixian County, Linfen City, north China's Shanxi Province, August 14, 2021. Due to the drought and lack of rain in the upper reaches of the Yellow River, which slows the river's flow, the waterfall turned green. (Photo: China News Service/Lu Guiming)