Aerial photo taken on June 11, 2019 shows the salt lake in Yuncheng City, north China's Shanxi Province. (Xinhua/Xue Jun)

Aerial photo taken on June 11, 2019 shows the salt lake in Yuncheng City, north China's Shanxi Province. (Xinhua/Xue Jun)

Aerial photo taken on June 11, 2019 shows the salt lake in Yuncheng City, north China's Shanxi Province. (Xinhua/Xue Jun)

Aerial photo taken on June 11, 2019 shows the salt lake in Yuncheng City, north China's Shanxi Province. (Xinhua/Xue Jun)

Aerial photo taken on June 11, 2019 shows the salt lake in Yuncheng City, north China's Shanxi Province. (Xinhua/Xue Jun)

Aerial photo taken on June 11, 2019 shows the salt lake in Yuncheng City, north China's Shanxi Province. (Xinhua/Xue Jun)