Grain-size Analysis of Surface Material Under Wind Erosion Using the Effective Surface Concept
✍ Scribed by Martz, Lawrence W.; Li, Long
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 254 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0360-1269
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✦ Synopsis
The grain mobility and roughness of a surface exposed to wind are dependent on the grain size of the surface particles. This paper deals with the temporal variation in the grain size of surface material using an analytical method based on the effective surface concept. The analysis of grain size data obtained from a wind tunnel experiment indicated that, above the threshold wind friction velocity for all surface particles, the grain-size distribution of surface particles was very similar to that of the parent material over a time period of 10 to 15 minutes. However, the mean grain size of surface particles apparently decreased over the initial time period of 2 to 3 minutes. We therefore confirm earlier studies that on a nonuniform grain bed a larger particle could be more mobile than a smaller particle if the wind friction velocity was higher than the threshold for the larger particle. However, this does not imply that the largest particle is most mobile due to the nonlinear dynamics of aeolian sediment transport processes.