Fig. 5.

Diagram showing the proposed recirculation region (shaded region) for a one-barrier case (top) and a two-barrier case (bottom). The recirculation region extends from the upwind barrier location (black bar) to a downwind distance of a) 6.5 h_b for the one-barrier case and b) 4 h_b for the two-barrier case. For both cases, the original source height (car icon) is denoted as z_src. If the original source is within the recirculation region, the source is moved to the location of the upwind barrier and to a source height of 0.75h_b (orange square)