Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions
We used a compact boundary layer wind tunnel equipped with a turbulence generator and a piezoelectric blown-sand meter to investigate the effects of the surface coverage of fine gravel on wind-blown sand flux. The vertical profile of wind-blown sand over a flat sand surface showed an exponential dis...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-09-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/11/10/1029 |
| _version_ | 1797552680388788224 |
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| author | Jiaqi Liu Reiji Kimura Jing Wu |
| author_facet | Jiaqi Liu Reiji Kimura Jing Wu |
| author_sort | Jiaqi Liu |
| collection | DOAJ |
| description | We used a compact boundary layer wind tunnel equipped with a turbulence generator and a piezoelectric blown-sand meter to investigate the effects of the surface coverage of fine gravel on wind-blown sand flux. The vertical profile of wind-blown sand over a flat sand surface showed an exponential distribution at all wind speeds, whereas the profile over gravel surfaces of 20% or greater coverage showed a non-monotonic vertical distribution. At 20% to 30% gravel coverages, a peak of wind-blown sand flux developed between 6 and 10 cm above the ground at all wind speeds because of less energy loss due to grain-bed collisions at that level. To analyze the erosional state of wind-blown sand, we used the Wu–Ling index (λ) of the mass-flux density of sand-bearing wind. Values of λ for all gravel coverages were greater than 1 at all wind speeds, indicating an unsaturated (erosional) state. Moreover, we found that the wind-blown sand flux at 4 cm height accounted for about 20% of the total flux regardless of wind speed and gravel coverage. This finding can simplify future estimations of total near-surface wind-blown sand flux based on field observations because such measurements can be taken at just one height. |
| first_indexed | 2024-03-10T16:04:32Z |
| format | Article |
| id | doaj.art-387c747ab61647b48bc6fea6e80b1921 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T16:04:32Z |
| publishDate | 2020-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-387c747ab61647b48bc6fea6e80b19212023-11-20T15:01:08ZengMDPI AGAtmosphere2073-44332020-09-011110102910.3390/atmos11101029Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid RegionsJiaqi Liu0Reiji Kimura1Jing Wu2Arid Land Research Center, Tottori University, Hamasaka 1390, Tottori 680-0001, JapanArid Land Research Center, Tottori University, Hamasaka 1390, Tottori 680-0001, JapanArid Land Research Center, Tottori University, Hamasaka 1390, Tottori 680-0001, JapanWe used a compact boundary layer wind tunnel equipped with a turbulence generator and a piezoelectric blown-sand meter to investigate the effects of the surface coverage of fine gravel on wind-blown sand flux. The vertical profile of wind-blown sand over a flat sand surface showed an exponential distribution at all wind speeds, whereas the profile over gravel surfaces of 20% or greater coverage showed a non-monotonic vertical distribution. At 20% to 30% gravel coverages, a peak of wind-blown sand flux developed between 6 and 10 cm above the ground at all wind speeds because of less energy loss due to grain-bed collisions at that level. To analyze the erosional state of wind-blown sand, we used the Wu–Ling index (λ) of the mass-flux density of sand-bearing wind. Values of λ for all gravel coverages were greater than 1 at all wind speeds, indicating an unsaturated (erosional) state. Moreover, we found that the wind-blown sand flux at 4 cm height accounted for about 20% of the total flux regardless of wind speed and gravel coverage. This finding can simplify future estimations of total near-surface wind-blown sand flux based on field observations because such measurements can be taken at just one height.https://www.mdpi.com/2073-4433/11/10/1029arid regionsboundary layer wind tunnelwind-blown sand fluxvertical profilesfine gravel |
| spellingShingle | Jiaqi Liu Reiji Kimura Jing Wu Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions Atmosphere arid regions boundary layer wind tunnel wind-blown sand flux vertical profiles fine gravel |
| title | Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions |
| title_full | Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions |
| title_fullStr | Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions |
| title_full_unstemmed | Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions |
| title_short | Vertical Profiles of Wind-Blown Sand Flux over Fine Gravel Surfaces and Their Implications for Field Observation in Arid Regions |
| title_sort | vertical profiles of wind blown sand flux over fine gravel surfaces and their implications for field observation in arid regions |
| topic | arid regions boundary layer wind tunnel wind-blown sand flux vertical profiles fine gravel |
| url | https://www.mdpi.com/2073-4433/11/10/1029 |
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