The characterization of the climatic potentiality of urban forms at local and micro scales: proposition of a morpho-climatic indicator

For analysing the climatic environment in the urban empty spaces two approaches ca be noted: the first one is based on the numerical simulations of the climatic physical parameters and the second one consists on climatic characterization by using a number of significant indicators of these empty spaces. We propose in this paper to discuss the operational aspect of the characterization approach in the analysis of climatic urban environment and we propose an alternative to this.

The principal interest of the morphological characterization is that we can obtain information on the climatic environment without passing by complex physical simulations. But one of the problems meet by the characterization methods is that these methods are not explicit. In the most number of cases the characterisation is based on an important number of morphological indicators. Add to this, we don’t always know the interaction between these indicators.

The principal object of this paper consists on a proposition of one explicit morphological indicator based on the geometrical 3D description of the empty spaces. This indicator, called “directional opening of empty spaces”, analyse both the microclimatic and the local climate environnements. It takes information on the climatic potentiality of the urban environment. The comparison of the characterisation results with aeraulique, solar, and lightness simulations takes acceptable results. For giving explicit information, the indicator was defined both by a numerical calculation and explicit graphical representation.