Sand dunes are scattered along the middle reaches of the Yarlung Zangbo River. The river's water volume decreases in the winter, revealing the riverbed. The freezing wind on the Tibetan Plateau blows the sand, which piles up into sand dunes on the riverbank. Planting trees is one of the main solutions to transform the sand dunes. Part of the land has turned into a dense forest after years of hard transformation efforts.