关键词: 沙尘暴, 跃变, 黄土高原

Abstract: Based on the data of sandstorms and precipitation, a study of sandstorms in the Loess Plateau and the neighboring areas has been made. Through analysis of relationship between mean annual number of sandstorms and mean annual precipitation, an original sandstorm zone and a secondary high-frequency zone of sandstorms have been found. The latter was formed as a result of human activities such as vegetation destruction and waste-land cultivation. The secondary sandstorm zone is 350 km to 500 km away from the original sandstorm zone, reflecting that the sandstorm zone in the Loess Plateau area has been shifted 350 km to 500 km to the southeast, as response to human impacts. Some abrupt change has been found around the belt of mean annual precipitation of 300 mm, where the original sandstorm zone suddenly shifts to the secondary high-frequency zone of sandstorms. Hence, this transition area can be regarded as an abnormally unstable area.

Key words: sandstorm, abrupt change, Loess Plateau