(221205) -- LANZHOU, Dec. 5, 2022 (Xinhua) -- This aerial photo taken on July 13, 2021 shows the view of a restored grassland by the Yellow River in Maqu County, Gannan Tibetan Autonomous Prefecture of northwest China's Gansu Province. This year's World Soil Day fell on Monday. Located on the northeast brink of the Qinghai-Tibet Plateau, Maqu County boasts an extensive presence of grasslands and wetlands, which had suffered a lot from degeneration and desertification before the end of the 20th century. Thanks to a series of ecological preservation and soil improvement programs in recent years, a substantial part of the once damaged vegetation has been restored in the county. (Xinhua/Chen Bin)