Submitted to: Earth Surface Processes and Landforms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2003
Publication Date: 4/23/2003
Citation: Zobeck, T.M., Stout, J.E., Van Pelt, R.S., Funk, R., Rajot, J.L., Sterk, G. 2003. Measurement and data analysis methods for field-scale wind erosion studies. Earth Surface Processes and Landforms. 28(11):1163-1188. Interpretive Summary: Accurate and reliable methods of measuring the amount of blowing dust are necessary to confirm and improve models used to predict erosion and develop new crop management systems. The equipment used to measure the dust, the properties of the fields measured and methods of analyzing the data are discussed in this paper. Characteristics of the field that should be considered include the field shape, length, uniformity of the field surface features such as texture, and roughness. The kind of samplers used will depend on how the dust is moving. Particles rolling along the ground may be caught by simply burying a bottle with the opening flush to the surface. Bouncing particles can be caught with dust traps mounted on a pole. Very small suspended particles can be captured using commercially available sampling equipment. The paper will also discuss a variety of other sampling and data analysis techniques. Topics will include a discussion of a number of samplers to use, weather station equipment needs, simple wind and dust measurement analysis techniques, and field soil surface characteristcs of importance.
Technical Abstract: Accurate and reliable methods of measuring windblown sediment are needed to confirm, validate, and improve erosion models, assess the intensity of aeolian processes and related damage, determine the source of pollutants, and for other applications. This manuscript will outline important principles to consider in conducting field-scale wind erosion studies and propose strategies of field data collection for use in model validation and development. Detailed discussions include consideration of field characteristics, sediment sampling principles, meteorological stations, and soil surface conditions. The field shape used in field-scale wind erosion research is generally a matter of preference and in many studies may not have practical significance. Maintaining a clear non-erodible boundary is necessary to accurately determine sampling fetch distance. A field length of about 300 m may be needed in many situations to approach transport capacity for saltation flux in bare agricultural fields. The types of samplers used for sampling aeolian sediment will vary depending upon the type of sediment to be measured. The BSNE and MWAC samplers appear to be the most popular for field studies of saltation. Suspension flux may be measured with commercially available instruments after modifications are made to ensure isokinetic conditions at high wind speeds. Soil surface conditions affect the wind profile and other processes such as sediment emission, transport, deposition, and soil erodibility. Knowledge of the temporal variation in surface conditions is necessary to understand aeolian processes. Use of a portable two-meter tall anemometer tower should be considered to quantify this variability of friction velocity and aerodynamic roughness in field-scale studies. Temporal soil properties that impact aeolian processes include soil surface roughness, dry aggregate size distribution, dry aggregate stability, and crust characteristics. Careful consideration of the climatic, sediment, and soil surface characteristics observed in future field-scale wind erosion studies will ensure maximum use of the data collected.