Boulders, trees, buildings, shrubs, and even small plants like grass and herbs can increase the frictional roughness of the surface and reduce wind velocity.
(Boulders, trees, buildings, shrubs, and even small plants like grass and herbs; can increase; the frictional roughness of the surface) (Boulders, trees, buildings, shrubs, and even small plants like grass and herbs; reduce; wind velocity)
Boulders, trees, buildings, shrubs, and even small plants like grass and herbs Boulders, trees, buildings, shrubs, and even small plants like grass and herbs
can increase reduce
the frictional roughness of the surface
wind velocity