Fig. 2: The qualitative study of flow pathways in synthetic urban forms shows the impact of urban porosity, order, and chord length on flood velocity distribution.
Non-dimensionalized flood velocity maps for unit cells of urban forms with (a–c) square and (d–f) hexagon-like patterns with porosity ϕ=0.6 and Mermin order χ=1.0, 0.8, and 0.6, respectively. The color bar on the right represents the velocity scale for all velocity maps. Gray squares represent flow obstructions. While the unit cell lu is ~ 33D, the channel length is set to 20lu to mitigate size effects. The normalized chord length distribution \(P({l}_{c}^{{\prime} })\) for each urban form is placed below each velocity map in panels (g–l); see the text for the definition.
