Zhangjiakou and Chengde in Hebei surrounding the dam is, Yongding river downstream drainage areas and three sand zone is the main area of the sandstorm sources around the world.

• 在京津周边就有张家口和承德的坝上、坝下地区及永定河下游三大沙区，是京津地区主要的风沙源之一。