This paper explores the aerodynamic characteristics of urban areas through the analysis of surface form, focusing on methods to estimate zero-plane displacement length (z_d) and roughness length (z_o). The study uses geographic information systems (GIS) to characterize the morphometry of 11 urban sites in 7 North American cities, including residential suburbs, industrial areas, and city centers. Various morphometric methods, such as the rule-of-thumb approach and those that consider height and plan areal fraction or frontal area index, are evaluated through sensitivity analyses. The results show that while most methods have merit, they can produce a wide range of values, and their performance varies with the complexity of the urban surface. The paper also discusses other aerodynamic characteristics like blending height (z_r) and surface conductance (g_{AM}), and compares morphometric predictions with micrometeorological estimates from wind and turbulence observations. Overall, the study highlights the challenges in accurately estimating aerodynamic parameters in urban environments and suggests recommendations for selecting appropriate methods based on the specific characteristics of the urban site.This paper explores the aerodynamic characteristics of urban areas through the analysis of surface form, focusing on methods to estimate zero-plane displacement length (z_d) and roughness length (z_o). The study uses geographic information systems (GIS) to characterize the morphometry of 11 urban sites in 7 North American cities, including residential suburbs, industrial areas, and city centers. Various morphometric methods, such as the rule-of-thumb approach and those that consider height and plan areal fraction or frontal area index, are evaluated through sensitivity analyses. The results show that while most methods have merit, they can produce a wide range of values, and their performance varies with the complexity of the urban surface. The paper also discusses other aerodynamic characteristics like blending height (z_r) and surface conductance (g_{AM}), and compares morphometric predictions with micrometeorological estimates from wind and turbulence observations. Overall, the study highlights the challenges in accurately estimating aerodynamic parameters in urban environments and suggests recommendations for selecting appropriate methods based on the specific characteristics of the urban site.