People walk on the streets wear full coverage, such as masks or other protective gear, in the ongoing sandstorm in Yinchuan, Northwest China's Ningxia Hui autonomous region on March 15, 2021. [Photo by Su Yong/For chinadaily.com.cn]

People walk on the streets wear full coverage, such as masks or other protective gear, in the ongoing sandstorm in Yinchuan, Northwest China's Ningxia Hui autonomous region on March 15, 2021. [Photo by Su Yong/For chinadaily.com.cn]

People walk on the streets wear full coverage, such as masks or other protective gear, in the ongoing sandstorm in Yinchuan, Northwest China's Ningxia Hui autonomous region on March 15, 2021. [Photo by Su Yong/For chinadaily.com.cn]

People walk on the streets wear full coverage, such as masks or other protective gear, in the ongoing sandstorm in Yinchuan, Northwest China's Ningxia Hui autonomous region on March 15, 2021. [Photo by Su Yong/For chinadaily.com.cn]

Many cities in Gansu reported very poor visibility, with the lowest reaching up to 150 meters, when the region was struck by the heaviest sandstorms since 2002, according to the local meteorological bureau on Monday. [Photo by Su Yong/For chinadaily.com.cn]

Many cities in Gansu reported very poor visibility, with the lowest reaching up to 150 meters, when the region was struck by the heaviest sandstorms since 2002, according to the local meteorological bureau on Monday. [Photo by Su Yong/For chinadaily.com.cn]

Many cities in Gansu reported very poor visibility, with the lowest reaching up to 150 meters, when the region was struck by the heaviest sandstorms since 2002, according to the local meteorological bureau on Monday. [Photo by Su Yong/For chinadaily.com.cn]