Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)

Aerial photo taken on Dec. 3, 2020 shows a view of the Mahuangliang Loess Geopark after snow in Yulin City, northwest China's Shaanxi Province. (Xinhua/Tao Ming)