Author
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Hagen, Lawrence |
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Submitted to: International Conference on Aeolian Research
Publication Type: Proceedings Publication Acceptance Date: 7/19/2002 Publication Date: 7/19/2002 Citation: In: J.A. Lee and T.M. Zobeck (eds.) ICAR5/GCTE-SEN Joint Conference; 2002; Center for Arid and Semiarid Lands Studies, Texas Tech University, Lubbock, TX. Interpretive Summary: Wind erosion control is usually achieved by combining a number of management practices in a single control system. Models that correctly simulate the wind erosion processes over a wide range of surface conditions are useful design tools. But one must still relay upon model users to develop optimum designs for various land uses. This report presents a summary of the effects of erosion processes on the selection and design of erosion controls, such as tillage ridges, field length, crop residues, strip crops, and wind barriers. Technical Abstract: Even though new models, such as WEPS, simulate wind erosion processes, one must still rely upon the model user to optimize the design of control systems. In this report, we suggest how processes can influence selection and design of erosion controls. When macro roughness is not fully armored, large ridges may be needed to maintain sufficient storage capacity to shelter mobile aggregates. In some wind regimes, control can be enhanced by separately optimizing the angles of crop strips and tillage ridges. Reducing field length limits abrasion of immobile soil aggregates and crusts by saltating aggregates. Computer simulations, revealed that one should avoid designs with intermediate field lengths that maximize soil loss per unit area. Reducing field length is also recommended for relatively stable fields that include small erodible areas that can destabilize downwind areas. Standing residue is generally 5 to 10 times more effective when combined with other controls, because their zone of erosion control expands with increases in threshold velocity of the soil surface. Barriers are often placed on strip crop borders. However, in some cases placing the carrier in the center of each strip can serve to reduce field length and thus, improve control. |
