A tourist takes photos at the Hukou Waterfall scenic spot on the Yellow River, which is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces, March 18, 2018. Warmer temperature and melting ice in upper reaches lead to the annual spring flood of the waterfall. (Xinhua/Liu Hongda)

Photo taken on March 18, 2018 shows the Hukou Waterfall scenic spot on the Yellow River, which is located on the border area between north China's Shanxi and northwest China's Shaanxi provinces. Warmer temperature and melting ice in upper reaches lead to the annual spring flood of the waterfall. (Xinhua/Liu Hongda)