A sea of clouds has turned Wuqi County in northwest China's Shaanxi Province into a floating wonderland. 

Wuqi County is under the jurisdiction of Yan'an City. Before 1998, the county had a soil erosion area of 3,696 square kilometers, representing 97.5 percent of the 3,791.5-square-kilometer county. Its soil erosion modulus reached 157,700 tons per square kilometer per year, one of the most severe soil erosion cases in Yan'an. 

In 1999, 1.6 million mu (about 600,000 hectares) of farmland was returned to forest. In 2012, the county returned 184.87 million mu of farmland to forests, the fastest development in the country at the time. 

The sea of clouds, which frequently appears in summer and autumn, are a result of the reforestation.