Explicit and implicit ground roughness modeling

In the computational model (CFD), ground roughness effect on the wind flow is modeled either using explicit roughness element discretization (provided that the computational cost is affordable) or implicitly, for example, by using fractal surfaces.

Abdi, D. and Bitsuamlak, G.T. (2016). Wind flow simulations in idealized and real built environments with models of various level of complexity, Wind & Structures, 22 (4), 503-524.
Aboshosha, H., A., Bitsuamlak, G.T., El Damatty, A. (2015). LES of wind in the built-environment: Inflow and roughness induced by fractal surfaces. Sustainable Cities and Society, 19, 46-60.
Abdi, D. and Bitsuamlak, G.T. (2014). Numerical evaluation of the effect of multiple roughness changes. Wind and Structures, 19(6), 585-601.