干旱区生态环境知识资源中心

Temporal and spatial characteristics of dust storms in the Xilingol grassland of northern China were explored in this paper, based on data of dust storms from the China Meteorological Data Sharing Service System. During the period of 1954-2007, the total dust storm events (DSE) for the Xilingol grassland decreased from the 1960s to the 1990s, and abnormally increased in the 2000s with clear inter-annual and inter-decadal variations as well as spatial differences. The annual mean DSE in the northwest part was generally more than those in the southeast part of Xilingol grassland, with the DSE increasing significantly in the northwestern part of Xilingol grassland in 2000s. The wind speed has a weak correlation with frequency, duration time, and intensity of DSE during the last decades. The influence of spring vegetation condition on the frequency of DSE should be given more attention, especially in the northwest part of the Xilingol grassland. The threshold wind speeds of DSE in different sub-regions of the study area range between 7.0 and 12.8 m/s. Maximum 10-min average wind speeds during DSE tended to decline between 1980 and 2007. The abnormally frequent and strong DSE occurring with lower wind speeds in the 2000s were probably closely related to local vegetation change and serious desertification.