Abstract: Aeolian researchers have recognized the importance of measuring the height profile of aeolian saltating flux and devoted a lot of effort to reliable measurement. In this paper, the height profiles of aeolian saltation flux are reconstructed on the basis of the profiles of mean particle velocity and relative particle concentration obtained by high-speed photography, a nonintrusive technique, in a wind tunnel. The results suggest that the mean particle velocity increases with height. The height profile of mean particle velocity can be expressed by a power function. Particle concentration decays exponentially with the square root of height. Mass flux profiles are derived by multiplying the mean particle velocity and concentration profiles. The reconstructed mass flux profiles are characterized by two sections. Above the peak point whose height was range from 1mm to 3mm, mass flux decays exponentially with height. Between the near-surface and the peak point layers, mass flux have no obvious change trend due to the influences of mid-air inter-particle collisions and initial impact on the bed. Two significant parameters, average saltation height and relative decay factor, are proposed to characterize variation with height of aeolian saltating flux. They are well correlated and imply that saltating particles can reach higher levels as wind velocity increases and particle size decreases and that mass flux decays more rapidly as wind velocity decreases and particle size increases.

Key words: aeolian saltation, mass flux, high-speed photography, measurement technique, Particle Tracking Velocimetry