This aerial photo taken on Oct. 4, 2022 shows the Hulan River estuary wetland park in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This aerial photo taken on Sept. 26, 2022 shows the Yangmingtan Bridge and the surrounding wetlands in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This photo taken on Sept. 6, 2018 shows the Sun Island scenic area in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This photo take on April 15, 2022 shows people enjoying themselves along the Songhua River in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This aerial photo taken on Sept. 26, 2022 shows the Songhua River in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This photo taken on July 30, 2019 shows a child playing along the Songhua River in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This aerial photo taken on July 1, 2020 shows a wetland park in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This aerial photo taken on Oct. 4, 2022 shows a view of the Sun Island scenic area in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua

This aerial photo taken on July 1, 2020 shows a wetland park in Harbin, northeast China's Heilongjiang Province. Photo: Xinhua