干旱区生态环境知识资源中心

Field experiments of dust production have been seldom performed in Chinese deserts that are identified as one of main dust sources in the world, and such an experiment to validate a dust production model (DPM) has not been made in China until now. Saltation flux, dust emission flux, surface features and meteorological parameters (Lf, Zo, Ri, etc.) were investigated in Mu Us Desert of China to verify the DPM model and accumulate dust emission data during the spring of 2002. It indicates that observed saltation fluxes from 0.07 to 8.00 g(.)m(-1) (.) s(-1) are in good agreement with the ones predicted by the DPM model when the constant of the saltation flux equation is tuned to about 2.61, which corresponds to wind friction velocities from 0.26 to 0.35 m(.)s(-1). Unfortunately, during three local dust emission events, the observed dust fluxes are from 1 to 3 mu g(.)m(-2.)s(-1), lower than the modeled ones, implying that the model needs to be improved further under lower wind velocity. In comparison with data from a sandy soil with physical crust and a loam soil, saltation fluxes of the loose sandy soil in Mu Us Desert are obviously higher, which suggests that deserts and sandy land with desertification are major dust sources in northern China.