Arid Zone Research ›› 2022, Vol. 39 ›› Issue (4): 1006-1016.doi: 10.13866/j.azr.2022.04.02

• Weather and Applied Climate • Previous Articles     Next Articles

Comparative study of the applicability of emission threshold determining method in the Taklimakan Desert

YANG Xinghua1,2(),MA Mingjie2,ZHOU Chenglong2,HE Qing2()   

  1. 1. School of Geographical Sciences, Shanxi Normal University, Taiyuan 030032, Shanxi, China
    2. National Observation and Research Station of Desert Meteorology, Taklimakan Desert in Xinjiang, Urumqi 830002, Xinjiang, China
  • Received:2021-12-01 Revised:2021-12-27 Online:2022-07-15 Published:2022-09-26
  • Contact: Qing HE E-mail:yxhidm@126.com;qinghe@idm.cn

Abstract:

Aeolian sand movement is a crucial surface process in the study of regional and global changes. As a key parameter in determining wind-sand movement occurrence, the emission threshold (threshold velocity, threshold friction velocity) is a core issue in the study of wind-sand movement. Taking the Taklimakan Desert as the target area, using synchronously observed wind-sand movement and meteorological data in the field, combined with mathematical model calculations, the applicability of five emission threshold judgment schemes from Stout, Kurosaki and Mikami (KM), Li Xiaolan and Zhang Hongsheng (LZ), Marticorena and Bergametti (MB), and Shao and Lu (SL) was quantitatively assessed, and the optimal scheme was used to determine the new emission threshold of the Taklimakan Desert. The following results are presented. (1) Uncertainties exist in all five schemes. The emission threshold determined by the KM scheme overestimates the dust emission time and the dust level flux to a certain extent. The four other schemes are opposite, but the KM scheme is the best. (2) The 2 m threshold velocity in the hinterland of the Taklimakan Desert varies from 4.0 m·s-1 to 6.0 m·s-1, and the threshold friction velocity varies from 0.24 m·s-1 to 0.36 m·s-1. Moreover, the emission threshold has seasonal differences, which is consistent with summer > autumn > spring > winter.

Key words: wind-blown sand movement, threshold velocity, threshold friction velocity, Taklimakan Desert