Determination of the aerodynamic resistance to heat using morphometric methods

The spatial estimation of the aerodynamic resistance to heat using morphometric methods was evaluated on the example of three different approaches using a digital surface model to calculate the roughness length for momentum and heat. The digital surface model was a result of manual digitising of a GoogleEarth image and another model retrieved from two stereoscopic SPOT images. The resulting values for the building area density and frontal area index were slightly lower than comparable values found in the literature, which could be attributed to the building structure. An empirical parameter α, used for the calculation of the roughness length for heat, was fitted to observational data. α was found to be higher than suggested by literature values. The three morphometric methods proved to follow the same principle, the spatial analysis, however, showed that they produced different results in some very dense areas