Fig. 2. Test of the single-layer model for the deposition velocity W_d, Eq. [15], against wind tunnel measurements of particle deposition to a sticky grass surface by Chamberlain (1967). Predictions are of W_d as a function of particle diameter d for vegetation of height 0.06 m and leaf area index 1, using the model of Raupach (1992)(1994) to calculate roughness length and other canopy aerodynamic properties. Data and predictions are for three wind speeds giving friction velocities of 0.35, 0.70, and 1.40 m s^-1. The solid line is the predicted terminal velocity W_t as a function of d (Malcolm and Raupach, 1991).