Wind tunnel and field calibration of five aeolian sand traps

The efficiency of five aeolian sand samplers was tested via wind tunnel exp eriments and field measurements. The samplers were: the Big Spring Number E ight (BSNE) sampler, the Modified Wilson and Cooke (MWAC) sampler, the Susp ended Sediment Trap (SUSTRA), the Pellet catcher (POLCA), and the saltiphon e. In the wind tunnel, the samplers were calibrated against an isokinetic s ampler (a modified Sartorius SM 16711 sampler with adjustable flow rate), a nd this for three sand types (median diameter: 132, 194 and 287 mum) and li ve wind speeds (ranging from 6.6 to 14.4 m s(-1)). In the field, seven cali bration tests of two weeks each were conducted. The absolute efficiencies o f the BSNE, MWAC and POLCA are more or less comparable and vary between 70% and 120%, depending on sediment size and wind speed. For the SUSTRA, the e fficiency is somewhat lower for fine sands and for wind speeds above 11 m s (-1). Finally, the saltiphone can accurately detect the periods of saltatio n transport, but in its current version, the instrument is not accurate whe n measuring the absolute saltation flux. The most recommendable sampler in the test is the MWAC, not only because of its high efficiency, but also bec ause its efficiency is independent of wind speed. (C) 2000 Elsevier Science B.V. All rights reserved.