Document Type : Research Paper
Authors
1 PhD Student in Rangeland Management, Department of Rangeland and Watershed Management, Faculty of Natural Resources, Isfahan University of Technology, Iran
2 Associate Professor, Department of Environmental Sciences, Faculty of Natural Resources and Desert Studies, Yazd University, Yazd, Iran
3 Associate Professor, Department of Rangeland and Watershed Management, Faculty of Natural Resources, Isfahan University of Technology, Iran
4 Associate Professor, Department of Environmental Sciences, Faculty of Natural Resources, Isfahan University of Technology, Iran
Abstract
Background and Objectives
Accurate measurement of wind erosion and dust intensity requires precise sediment traps. However, traps with varying geometric and aerodynamic properties differ in their efficiency for collecting, retaining, and selecting wind-blown particles. This study evaluates the collection efficiency, retention capacity, and particle selectivity of two widely used wind erosion sediment traps—the Cox Sand Catcher (CSC) and the Modified Wilson and Cooke (MWAC)—in Iran, where they have recently been implemented for wind erosion monitoring.
Methodology
Tests were conducted using soils from two wind erosion hotspots in Iran: God-e-Govar (Bafq) and Gavkhuni (Sajzi). A suction-type wind tunnel was equipped with custom-designed bases for the traps and soil trays. Experiments were performed in a controlled laboratory setting at wind speeds of 6.1, 7.88, 9.35, and 10.62 m/s. Collection efficiency, retention capacity, and particle selectivity were measured for both traps.
Results
For loamy sand soil, the CSC trap’s collection efficiency at wind speeds of 6.1, 7.88, 9.35, and 10.62 m/s was 20.61 ± 1.11%, 43.06 ± 2.47%, 35.90 ± 5.12%, and 29.41 ± 1.78%, respectively. For sandy soil from Bafq, efficiencies were 25.35 ± 3.35%, 47.33 ± 4.00%, 41.68 ± 5.19%, and 33.11 ± 3.83%. In contrast, the MWAC trap’s efficiencies for loamy sand were 29.75 ± 4.02%, 31.95 ± 7.18%, 57.57 ± 5.21%, and 62.84 ± 5.82%, and for sandy soil, 43.92 ± 8.83%, 44.23 ± 4.34%, and 47.19 ± 2.97% at the respective wind speeds. Both traps exhibited retention efficiencies exceeding 95% for both soil textures. Selectivity was lower for very fine particles (<100 µm) and very coarse particles (>1 mm), but the CSC trap showed greater selectivity for sand particles due to its design.
Conclusion
The MWAC trap’s collection efficiency increased with wind speed for both loamy sand and sandy soils, whereas the CSC trap’s efficiency peaked at approximately 8 m/s before declining. These differences stem from the traps’ geometric and aerodynamic designs. Both traps showed reduced selectivity for very fine (<100 µm) and very coarse (>1 mm) particles, with the CSC trap being more selective for sand particles. Collection efficiency, retention, and selectivity depend on soil particle size distribution, wind speed, and trap design.
Keywords
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