Implementation of a solar model and shadow plotting in the context of a 2D GIS

The adaptation of public spaces to episodes of intense heat is now a major challenge for cities. With this in mind, this article presents a contribution aimed at delineating and handling the shadows on the ground or in a horizontal plane at a given height, whether it comes from buildings, street furniture or the tree cover. After a comparison with shadows obtained via two reference tools, we present two urban sites that mix shadows of different origins and, in addition, different indicators. The results of the simulations are compared with pyranometric surveys carried out on site. The aim of these indicators is to assist urban designers with solutions that make it possible to distinguish the respective shadow contributions, their annual evolution and potential spatial or temporal continuities.