Modeling multirow wind barrier density

Field multirow wind reduction patterns can be expressed with a Barrier Effe ctiveness Index (BEI), but this index cannot be used to model wind barrier effects on wind erosion. The effect of barrier density on wind passing thro ugh the barrier must be described to model wind barriers. The drag effect o f the wind passing through field barriers was simulated in a laboratory win d tunnel. Total drag in the wind tunnel was measured for simulated barriers with various row number-spacings-densities and the drag was correlated wit h BEI (r(2) = 0.84). This empirical relationship permitted the development of the the Equivalent Optical Density (EOD) from optical density (OD) of ea ch row (N), barrier height (H) and spacing between rows (RS). [GRAPHICS] EOD values were computed and correlated to total drag values. The relations hip was then tested on additional barriers, and the resulting overall corre lation (r(2) = 0.92) was significant. Using the EOD equation, the wind barr ier effects were computed for one to eight row (N) barriers, five optical d ensities, and three spacings between rows EOD can be used to compute wind r eduction patterns for the Revised Wind Erosion Equation (RWEQ) model. This permits the design of a wind barrier system (number of rows and plant densi ty within each row) that will be most effective in reducing wind erosion fo r the farmer.