Deposition of particles to a thin windbreak: The effect of a gap

It is shown that the ‘bleed velocity’ through the ‘fabric’ of a thin windbreak or shelterbelt is practically insensitive to the existence of nearby holes or gaps in the fabric. This provides the basis for a straightforward extension of an earlier formula for particle ‘scrubbing’ by a thin windbreak, to account for irregularities of the filtering vegetation or mesh.