Abstract: This paper is probed into the threshold velocity(u_t) calculation of Tazhong area,Taklimakan Desert,Xinjiang,China using the parameterization scheme.Firstly,we classified the dust weather combining the date of sand saltation,and then acquired the threshold velocity through the schemes of MARTICORENA and SHAO respectively.In order to test the accuracy of the u_t,we estimated the horizontal sand flux,and the results are as follows:(1) In the non-dust weather,the number of saltation particles was less than or equal to 10 000;when the sand blowing,the number of saltation particles was between 10 001 and 20 000;and in the sand storm,the number of saltation particles was more than 20 000. (2) The average threshold velocity was 4.88 m·s^-1 with the parameterization scheme of MARTICORENA and the average threshold velocity was 6.24 m·s^-1 with the parameterization scheme of SHAO,the threshold velocity was the highest in non-dust weather and the smallest in sand storm. (3) During the study period,the total horizontal dust flux was 732.9 kg·m^-1,and the horizontal dust fluxes were 125.2,80.9 and 526.8 kg·m^-1 in non-dust weather,the sand blowing and the sand storm respectively.The parameterization scheme of SHAO was suitable to estimate the horizontal dust flux in the study period,the non-dust weather and the sand blowing,while the parameterization scheme of MARTICORENA was suitable to estimate the horizontal dust flux of sand storm.

Key words: the threshold velocity, parameterization scheme, Tazhong