Aerial photo taken on May 24, 2019 shows workers at the construction site of an ecological management project by the Xisha River in Qian'an, north China's Hebei Province. Qian'an carried out projects to tackle environmental deterioration and water shortage of the Xisha River. (Xinhua/Yang Shiyao)

Aerial photo taken on May 24, 2019 shows workers at the construction site of an ecological management project by the Xisha River in Qian'an, north China's Hebei Province. Qian'an carried out projects to tackle environmental deterioration and water shortage of the Xisha River. (Xinhua/Yang Shiyao)

Aerial photo taken on May 24, 2019 shows workers at the construction site of an ecological management project by the Xisha River in Qian'an, north China's Hebei Province. Qian'an carried out projects to tackle environmental deterioration and water shortage of the Xisha River. (Xinhua/Yang Shiyao)