Photo taken on Aug. 26, 2021 shows the scenery of Zedang Lake at Guan'egou national forest park in Dangchang County of Longnan City, northwest China's Gansu Province. (Xinhua/Ma Xiping)

Aerial photo taken on Aug. 26, 2021 shows the scenery of Zedang Lake at Guan'egou national forest park in Dangchang County of Longnan City, northwest China's Gansu Province. (Xinhua/Ma Xiping)

Photo taken on Aug. 26, 2021 shows a waterfall at Guan'egou national forest park in Dangchang County of Longnan City, northwest China's Gansu Province. (Xinhua/Ma Xiping)

Aerial photo taken on Aug. 26, 2021 shows the scenery of Zedang Lake at Guan'egou national forest park in Dangchang County of Longnan City, northwest China's Gansu Province. (Xinhua/Lang Bingbing)

Aerial photo taken on Aug. 26, 2021 shows the forest scenery at Guan'egou national forest park in Dangchang County of Longnan City, northwest China's Gansu Province. (Xinhua/Lang Bingbing)

来源：Xinhua