Dust uplift potential in the Taklimakan Desert: an analysis based on different wind speed measurement intervals

Abstract

A wind speed data set at a temporal resolution of 1 min, observed in the hinterland of the Taklimakan Desert (Tazhong) from September 1, 2008, to August 31, 2010, was used to investigate the diurnal and seasonal cycles of high wind speeds and dust uplift potential (DUP), and to investigate the effect of wind speed measurement time on the DUP in different seasons. The results suggested that high wind speeds, i.e., greater than the threshold wind velocity (TWV) for wind erosion, mainly occurred during the daytime (08:00–20:00) and the frequency of wind speeds above the TWV exhibited a large variability from season to season: spring (6.4%) > summer (5.6%) > autumn (1.7%) > winter (0.8%). The cumulative DUP was 50% on June 17 and increased to 90% on September 1, with 75.4% of the DUP generated between April 1 and July 31 over the 2-year study period. The results indicated that a different temporal resolution of wind speed affected the calculation of DUP. The DUP was 9.93 × 106 m3/s3 when wind speed was measured at 1 min, 8.96 × 106 m3/s3 at 5 min, 8.51 × 106 m3/s3 at 10 min, and 8.32 × 106 m3/s3 at 15 min. The discrepancies in the DUP when wind speed was measured at different time intervals followed the order of winter > summer > autumn > spring. From an analysis of the diurnal DUP and wind speeds measured at different time intervals, it was found that the main deviation occurred in the early morning and later at night. If the mean wind speed was measured over a time interval of 10 min or longer, there was a certain error in evaluating the damage from eolian activities.